While I have the head and manifolds off....

[Matt Wilson]

Hi folks – my apologies in advance for the long message….

I have the head and manifolds off the 230 engine in my 1949 Power Wagon, so I can paint and do other work to them. While I have them off, I am wondering if I should do something to address the valves. Let me explain....

Some 8 - 9 years ago, I rebuilt the engine, being meticulous about everything, but when I checked for proper valve-to-seat contact, some had narrow contact widths, which widened and narrowed all the way around the pattern (not consistent width). The manuals state that the seat width (and presumably the width of the contact area) should be 1/16" (0.0625"), not to exceed 3/32"(0.094"). My notes from that time indicate that all exhaust valves were right on the money, having contact widths of 4/64” (i.e., 1/16"). However, some intake valves had contact widths as low as 0.020 - 0.030" (less than half of required specs). To check the patterns, I used Prussian Blue and a technique of "popping" the valves against the seats to mark the pattern, then measured the contact widths.

I went ahead and installed the engine, and it ran pretty well, but not as smoothly as expected. So with probably less than a thousand miles on the engine, I did a compression test, cold and warm. Readings were between 140 - 155 psi either way. So far, so good. I then did a cylinder leak down test, and most cylinders showed 15 - 20% pressure drop. Not so good. Two showed between 5 – 10%. Although the exhaust valve contact patterns had looked fine, hissing could be heard from the exhaust pipe when testing some of the cylinders. Some cylinders also produced a noticeable hissing from the crankcase (oil filler cap), indicating leakage past rings. None had any significant hissing from the intake, despite these valves having poor contact patterns. So the leak down results did not necessarily correspond to valve contact patterns. I have now put 7,000 - 8,000 miles on the engine, with no noticeable degradation in performance, but the leak down test results, and the poor valve contact pattern, have lingered at the back of my mind.

So.....now that I have the head and manifolds removed, would it be advisable to do some light lapping to make the contact widths more correct and uniform? Perhaps this would help the leak down readings and maybe make the engine run smoother? But if the valves were really the culprits, would they have burned by now? I know lapping is not the preferred method of improving valve sealing for some folks (this thread discusses it http://www.powerwagonadvertiser.com/...hlight=lapping), but there don't seem to be any machine shops with portable valve grinders around here, and the engine is NOT coming out of the truck for the foreseeable future, unless something really major happens.

I should probably repeat the valve contact checks first, now that the engine has run a few thousand miles. Correct me if I’m wrong, but I think the contact check (and lapping, for that matter) could be done without removing the camshaft.

Can I use a vacuum device to check the sealing of the valves while the head is off? I have an electric vacuum pump for A/C use, and also a hand vacuum pump, so I suppose I could adapt one of those to fit the intake or exhaust ports and see if the valves will hold vacuum. I’d appreciate any suggestions on this, though.

Thanks and Merry Christmas!

[Charles Talbert]

Curiousity

Did you replace both the intake and exhaust seats when the engine was overhauled? Did you do a 3 angle seat job at this time? Having the proper seat angles at the onset will make a world of difference. Were the old valves ground and reinstalled or did you replace with new valves? Were the springs replaced with new? Did you install appropriate valve spring shims in relation as to whether old springs were reused or new ones were installed? Is there a chance any of the springs got installed upside down?

Answers to these questions, I could likely share more.

[Gordon Maney]

I am understanding from your remarks that your seat widths vary around their perimeter. When this previous work was done, were the valve guides and valves replaced?

If the guides are not round and straight, if the valve stems are worn, you will not get a concentric seat. The eccentric seats you describe point to worn parts. I am speaking from ideals which include perfection.

I am interested in Charles' comment about upside down valve springs. I have none in front of me here and currently have no disassembled engine to examine.. Charles, what is the effect of that?

[Charles Talbert]

Valve springs in a 230 have a defined top and bottom. If you look at a spring, you can easily see the coils are wound tighter on 1 end than they are on the other. The closer wound coils always go toward the top when installed. If they are installed tight coils down, it can effect the valve action, especially at higher RPM. This is especially true if some are installed correctly while others may be wrong, as would be the likely situation if the installer was not aware of the difference.

I was getting ready to go out for a family gathering when I did the post asking the questions earlier this afternoon; I should have also thought of the guides, and if they were replaced. The scenerio this gentleman described makes me wonder about worn components in play as well, that was the reasoning behind the various questions.

[Matt Wilson]

Hi Gordon & Charles, since some of your questions overlap, I will try to answer both at the same time.

All valves were brand new, although the second machinist opted to grind them a bit, informing me that new ones often are not true out of the box. I say "second machinist" because much of the work done by first machine shop, which had been highly recommended, had to be re-done (long story). The first machinist, by the way, did the work on the valve seats.

I believe the exhaust seats were replaced, but my memory does not let me be 100% sure of this, and I cannot find any notes or receipts for this. I have notes and receipts for most other items pertaining to the truck, but not this. I don't think the intake seats were replaced. I am certain that both sets of seats were ground, or at least were supposed to be ground. At the time, I think I assumed they would be done with a 3-angle grind, since I thought this was the industry standard, and I don't recall whether I specifically asked the machinist about it, and we all know what happens when we assume.

All valve guides were replaced with new ones. I believe I would have checked for excessive play between the new valves and new guides, using a dial indicator, but I don't have any notes to prove it. Beyond this, I'm not sure if I would have performed any other checks on the guides. I may have taken some caliper measurements of the I.D.'s, but I can't be sure. Again, though, they were new parts (or maybe NOS).

The springs were new, and came with the camshaft. The camshaft was a high-performance one from VPW, intended to improve highway driveability, and the springs were supposedly of a higher spring rate than stock, to go with the camshaft. I don't remember if any shims came with the springs or not, but of course, I could easily check. I also don't remember the springs having a "correct end up," but I am aware that some springs are this way, and I would likely have checked for that. I have wondered if the high-performance cam could be causing the less-than-smooth running.

To answer one of Gordon's questions, yes, for several of the seats, the seat width, or at least the width of the contact pattern revealed by the Prussian Blue, varied along the perimeter of each seat, being wider in some places and narrower in others on the same seat. As I mentioned before, I used the method of "popping" the valves against their seats to check the contact patterns. I did not use the method of rotating the valves while in contact with the seats. Maybe that would have given me a different-looking result?

Looking through my notes some more, I see that I performed a test on each valve to determine how long it would take for some kind of liquid (probably carb or brake cleaner) to seep past the closed valves. My notes aren't so good, but I think I probably turned the engine upside-down on the stand and sprayed some cleaner into each intake and exhaust port and waited for signs of liquid seepage past the valves. The notes indicate that none of the valves showed signs of any seepage after several minutes, except for the #1 cylinder intake valve, which produced one drip about every two minutes. Based on this, I guess I decided to go ahead and button up the engine and install it.

[Charles Talbert]

Hi Gordon & Charles, since some of your questions overlap, I will try to answer both at the same time.

All valves were brand new, although the second machinist opted to grind them a bit, informing me that new ones often are not true out of the box. I say "second machinist" because much of the work done by first machine shop, which had been highly recommended, had to be re-done (long story). The first machinist, by the way, did the work on the valve seats.

I believe the exhaust seats were replaced, but my memory does not let me be 100% sure of this, and I cannot find any notes or receipts for this. I have notes and receipts for most other items pertaining to the truck, but not this. I don't think the intake seats were replaced. I am certain that both sets of seats were ground, or at least were supposed to be ground. At the time, I think I assumed they would be done with a 3-angle grind, since I thought this was the industry standard, and I don't recall whether I specifically asked the machinist about it, and we all know what happens when we assume.

All valve guides were replaced with new ones. I believe I would have checked for excessive play between the new valves and new guides, using a dial indicator, but I don't have any notes to prove it. Beyond this, I'm not sure if I would have performed any other checks on the guides. I may have taken some caliper measurements of the I.D.'s, but I can't be sure. Again, though, they were new parts (or maybe NOS).

The springs were new, and came with the camshaft. The camshaft was a high-performance one from VPW, intended to improve highway driveability, and the springs were supposedly of a higher spring rate than stock, to go with the camshaft. I don't remember if any shims came with the springs or not, but of course, I could easily check. I also don't remember the springs having a "correct end up," but I am aware that some springs are this way, and I would likely have checked for that. I have wondered if the high-performance cam could be causing the less-than-smooth running.

To answer one of Gordon's questions, yes, for several of the seats, the seat width, or at least the width of the contact pattern revealed by the Prussian Blue, varied along the perimeter of each seat, being wider in some places and narrower in others on the same seat. As I mentioned before, I used the method of "popping" the valves against their seats to check the contact patterns. I did not use the method of rotating the valves while in contact with the seats. Maybe that would have given me a different-looking result?

Looking through my notes some more, I see that I performed a test on each valve to determine how long it would take for some kind of liquid (probably carb or brake cleaner) to seep past the closed valves. My notes aren't so good, but I think I probably turned the engine upside-down on the stand and sprayed some cleaner into each intake and exhaust port and waited for signs of liquid seepage past the valves. The notes indicate that none of the valves showed signs of any seepage after several minutes, except for the #1 cylinder intake valve, which produced one drip about every two minutes. Based on this, I guess I decided to go ahead and button up the engine and install it.

Very lightly grinding new valves is fine, then you know they are right. Of course I'm unaware of 1st machinist issues, so I might could comment further if details with whatever issues concerned you there were made known.

From what you say about the valve seats, it is still unknown as to whether either was replaced. My assumption would be that possibly the exhaust seats may have been, and likely the intake seats were not since originals are machined into the block deck and are not replaceable except to counter bore the deck so new replaceable seats can be installed. This is the better option for a number of reasons. 2 reasons why I like it is that by installing new, the actual seat area can be held higher, and closer to original height. If regrinding the original seat area using the 3 angle process; the original intake valve seat area is lowered somewhat because of metal removal. Close monitoring of needed valve spring shim is very important in this process so that correct spring pressure is maintained. What I'm saying here is the more material that is removed, the lower the valve sits in its seat. The lower it sits, the lower the spring pressure becomes. I'm not familiar with the upgrade cam and springs you got from VPW; so I can't comment on any changes that may have brought about and maybe should have been considered when building up the valve train. However, I'll assure you without doubt that there should have been some special attention paid when doing this change. I would have thought that very detailed info should be furnished with any upgrade component explaining everything in fine detail for the installer. The message I'm getting from you is telling me that was not the case; if I'm correct, that prompts me to say that I do not understand once again why VPW does some of the things they do, or don't do. All else I can say is that isn't my style of doing business, I'll have to leave it there unless I had more info to go on.

If guides were new current production, they are bored very close to correct guide/stem clearance. Intake and exhaust guides are a different bore. We always run a correct sized reamer through the guides after installation just as a double check, but most of the time the bore is good and the reamer cuts very little or nothing at all. If NOS guides were used, this is very different. They will always require reaming to size after installation. This requires and exact size reamer for the process. If the machinist did not have the exact sized reamer, chances are he grabbed something out of his box that was close and went at it. I've seen this happen many times and it is one huge reason why we do our own engine build up in house. We have the right tooling for a precision fit. Getting back to seat grinding, the seat grinder must have a centering pilot to locate it and keep a perfect center. The pilot uses the bore of the guide to achieve a perfect center. If the guides are not reamed precisely and a precisely sized pilot used, the seat will not be precisely ground. The unknown story of the 1st machinist has me wondering about precision in all this. There is another issue also, exhaust guides go in 1 way, while intake guides go in the exact opposite. This gives the needed heat relief to the exhaust valve stems so they don't tend to stick in the guides as a result of the higher heat they experience. Were the guides installed correctly?

I'm not a fan of the valve pop method for checking anything. I do believe lapping to a minimal degree is necessary and helpful in these engines. Let me say that if you begin a lapping process and it reveals that obviously something isn't coming together as it should; you don't need to get extensive with lapping in trying to correct an obvious seating issue, but instead it is time to look back at the person that did the valve set up at the machine shop, or back at yourself if you did it. If minor lapping doesn't bring things together quickly, lapping isn't the proper fix for something that didn't happen like it should have during a prior step. The drip test you described was a killer with the drip you had on #1. There should have been no drip, you should have corrected that absolutely before continuing; lapping likely would have corrected the dripping. Whatever your reason was to overlook that and continue to button it up, well I just don't get it. Why do the drip test unless you intended to take care of any issue it brought out before moving on? If liquid will gravity drip past, 120# pressurized air certainly will leak past. I'd guess this is most likely the reason for the things you hear and don't like right now. Assuming a proper 3 angle job was done because you thought that was the norm; well that doesn't make sense either; either YOU KNOW it was done right or it is not wise to proceed. It is possible to achieve a good valve job without lapping if all the precision machining necessary to achieve that has been done well. However nobody can just assume that has happened, even the precision machinist himself, unless he uses fool proof testing methods to check his work, he simply cannot know for sure. The newer engines of today are much more precisely machined when built, that makes successful no lap valve jobs much easier to achieve. Remember that with a 230 you are working with an engine that was machined in many cases over 60 years ago using equipment not even close to the precision machinery used in new engine manufacturing today. If no lapping at all was done, it is my opinion that likely you are now reaping the undesireable result of that. We always lap a modest amount and check visually around the valve face/seat area with light injected through the intake/exhaust ports with no pressure applied against the valve. When satisfied with the result, the valve is removed and the valve face and seat contact areas are examined very closely checking seat width, contact area location on the valve face, etc. It is a method that has never failed us, and we KNOW there will be a tight, leak proof seal when the spring is installed. Proper shimming also plays a huge role; even a new spring will take on a heat set and lose some tension as soon as the engine heats up the first time. Proper shim will put the original specific spring tension back into place. Rule of thumb is to use .030" thick shim with new original type springs to overcome the heat set tension loss. If the valves and seats were ground and reused, it will take at least .060". This really needs to be calculated in accordance with exactly what was done during your specific repair process. In your case, you would need info based on the update springs you used as well as calculation based on what was done to the seats. The fact that the new valves were faced before installing must come into the equasion also. Without all this being considered, proper spring tension is not likely to be achieved in your set up.

[Matt Wilson]

Charles,

The first machinist came highly recommended by a co-worker who had done many auto restorations and mods, and was regarding by other "motor heads" as having very high standards. He said this machinist was the only one who had ever provided him with satisfactory results in every aspect of the job. My experience, however, was that the results were DIS-satisfactory in practically every aspect of the job. Most of the troubles arose with parts of the engine not related to the valve train, and I ended up having to purchase some parts to replace ones that he ruined, and also took some parts to another shop to have the first guy's work corrected. Too much to go into here, unless you are interested.

As for seat replacement, your assumption that exhaust seats were replaced and intakes were not is fair enough, since I have no other information at present. However, with the head removed, I can see what appears to be circular outlines around some of intake seats, indicating that someone may have installed intake seats in some places at some point in the past.

I do not recall any special instructions from VPW regarding shimming or spring orientation, and I certainly would have paid attention to that. I pulled the valve covers and actually removed the valves yesterday. I could not get the springs out, though, as they tend to hang up on the valve guides on the upper end, and the tappets on the lower end. However, looking at them installed in the engine, I could see no difference in coil spacing between upper and lower ends of the springs. It could be that these springs, being aftermarket to go along with the hi-performance camshaft, may not have a difference from one end to the other. I will call VPW to inquire.

With the valves removed, I got a good look at the valve guides. They are indeed installed correctly, with the counter-bored end upward for the exhaust valves, and downward for the intakes. I don't know if they are new or NOS guides.

As for not addressing the #1 cylinder intake valve with the leak that showed up during the liquid leak test, I was under the impression at the time that if there was a problem, the liquid would begin to seep out in a matter of a few seconds. How long is required to hold a valve in place with no leaks before the test is considered complete? I understand that you say there should never be a leak, but I'm wondering how long do I hold the valve in place before I can deem it to have no leaks, and move on to the next valve. 5 minutes? 15 minutes? 1 hour? Just wondering. This particular valve, by the way, did NOT indicate a problem during the air pressure leak down test. In fact, during the compressed air leak down test, this cylinder showed the best leak down results of all the cylinders, with only 6% pressure loss. As I mentioned before, the leak down test did not provide results that I would have expected based on the valve contact pattern checks that I performed.

Also, the engine runs as well now as it did the first day I fired it up after the rebuild. I just have concerns that it may not stay that way for long if the valves were not done right. And it never was 100% smooth to begin with, which I'm not sure if that has anything to do with valves or not. How long does it take for valves to burn when the valve job is not quite right? (In reality, the last time I ran the engine was 4 years ago, as I was performing other work on the truck, and then life got busy and I had no time to complete it. I am in the process of getting it back together so I can fire it up and start driving it again.)

You mention springs taking on a heat set. I'm confused by this, as the factory did not install shims to correct for this, at least not to my knowledge.

With the valves now out of the engine, I can get a better look at them. I do not see any obvious signs of burning of the valves or seats. It seems that the contact wear patterns are still inconsistent, showing wide areas and thin areas, all on the same valve. I'll try to post some photos to see if I am looking at it correctly. I am also going to pick up my head from the machine shop, so I will take the valves there for them to look at. One thing I noticed is that there seems to be a large amount of carbon build-up on the intake valves. Seems like a lot for just a few thousand miles. I will post a photo of that, as well.

Today I plan to measure the valve stem diameters, as well as how much play the valves have when installed in their guides. I'll post here again with the results.

Your input is very much appreciated. Thanks!

[Charles Talbert]

Charles,

The first machinist came highly recommended by a co-worker who had done many auto restorations and mods, and was regarding by other "motor heads" as having very high standards. He said this machinist was the only one who had ever provided him with satisfactory results in every aspect of the job. My experience, however, was that the results were DIS-satisfactory in practically every aspect of the job. Most of the troubles arose with parts of the engine not related to the valve train, and I ended up having to purchase some parts to replace ones that he ruined, and also took some parts to another shop to have the first guy's work corrected. Too much to go into here, unless you are interested.

As for seat replacement, your assumption that exhaust seats were replaced and intakes were not is fair enough, since I have no other information at present. However, with the head removed, I can see what appears to be circular outlines around some of intake seats, indicating that someone may have installed intake seats in some places at some point in the past.

I do not recall any special instructions from VPW regarding shimming or spring orientation, and I certainly would have paid attention to that. I pulled the valve covers and actually removed the valves yesterday. I could not get the springs out, though, as they tend to hang up on the valve guides on the upper end, and the tappets on the lower end. However, looking at them installed in the engine, I could see no difference in coil spacing between upper and lower ends of the springs. It could be that these springs, being aftermarket to go along with the hi-performance camshaft, may not have a difference from one end to the other. I will call VPW to inquire.

With the valves removed, I got a good look at the valve guides. They are indeed installed correctly, with the counter-bored end upward for the exhaust valves, and downward for the intakes. I don't know if they are new or NOS guides.

As for not addressing the #1 cylinder intake valve with the leak that showed up during the liquid leak test, I was under the impression at the time that if there was a problem, the liquid would begin to seep out in a matter of a few seconds. How long is required to hold a valve in place with no leaks before the test is considered complete? I understand that you say there should never be a leak, but I'm wondering how long do I hold the valve in place before I can deem it to have no leaks, and move on to the next valve. 5 minutes? 15 minutes? 1 hour? Just wondering. This particular valve, by the way, did NOT indicate a problem during the air pressure leak down test. In fact, during the compressed air leak down test, this cylinder showed the best leak down results of all the cylinders, with only 6% pressure loss. As I mentioned before, the leak down test did not provide results that I would have expected based on the valve contact pattern checks that I performed.

Also, the engine runs as well now as it did the first day I fired it up after the rebuild. I just have concerns that it may not stay that way for long if the valves were not done right. And it never was 100% smooth to begin with, which I'm not sure if that has anything to do with valves or not. How long does it take for valves to burn when the valve job is not quite right? (In reality, the last time I ran the engine was 4 years ago, as I was performing other work on the truck, and then life got busy and I had no time to complete it. I am in the process of getting it back together so I can fire it up and start driving it again.)

You mention springs taking on a heat set. I'm confused by this, as the factory did not install shims to correct for this, at least not to my knowledge.

With the valves now out of the engine, I can get a better look at them. I do not see any obvious signs of burning of the valves or seats. It seems that the contact wear patterns are still inconsistent, showing wide areas and thin areas, all on the same valve. I'll try to post some photos to see if I am looking at it correctly. I am also going to pick up my head from the machine shop, so I will take the valves there for them to look at. One thing I noticed is that there seems to be a large amount of carbon build-up on the intake valves. Seems like a lot for just a few thousand miles. I will post a photo of that, as well.

Today I plan to measure the valve stem diameters, as well as how much play the valves have when installed in their guides. I'll post here again with the results.

Your input is very much appreciated. Thanks!

If the adjustment screws on the tappets are all the way down original type springs will come out; since yours are not original, I can't comment further about that.

You should not have liquid leaks if you held it until infinity; that is why we use a light test as an initial check without spring pressure. The valve is simply sitting on its seat without even thumb pressure applied. When you see no light visible, it will be a leak proof assembly.

How long does it take for a valve to burn; impossible question. That would mostly depend on the degree of what was not correct.

Can't answer ifs and ands about what was or was not done during manufacture. It is a fact that valve springs take a heat set, you are best off adjusting to counter act that in order to keep spring pressure at or very near original specs. Shimming for what ever your particular situation is takes care of the particular issues. How this may apply to the springs you have in place now, I can't answer as I have not used them.

Inconsistent contact patterns definitely suggest that things could be better than they are in this particular case. Not being able to see, measure, check loose motion as to stem to guide clearance, etc, inspect seats and valve faces; that's all I can say without more info.

As for carbon build up on the intake valves, this very likely is related to gas being in the tank too long. When you run gas that is old, it tends to break down and will absolutely cause excessive build up on the intakes. If this practice continues, it will build into a hard tar like substance and will eventually stick the valves in the guides. You can't leave the gasoline we buy today in the tank for very long without this becoming a huge issue. Best advice I have, run the tank and carb DRY before it is to sit for more than a couple of weeks. This issue is argued as not happening in some areas of the US and may suggest gas sold in some areas may not break down as quickly as others. We have seen it go stale in 2-3 weeks to the point of being no good for anything. Some suggest I'm nuts, however I've seen them stuck so bad it took a slide hammer puller to remove the valves. What you have seen on intake valves is the beginning of a real nightmare. Clean the stuff off using a scratch wheel before you reinstall, and keep the gas fresh. Sta-Bil will help some in the short term, (extremely short) but is no good for extended storage; never mine what the label says. I'm talking seeing is believing proof.

[Matt Wilson]

Ok, I measured the stem diameters of all valves using a micrometer that reads to 4 decimal places (I guess most of them do, but I'm just clarifying). I measured each stem in 6 places - 3 along the length of the stem in one plane, then rotated the valve 90 degrees, and measured in another 3 places along that plane. All valves were within spec for brand new parts, being between 0.340 - 0.341". I also checked some of them in areas where there is no contact with the guides, just to get an un-worn dimension, and came up with diameters consistent with those of the contacted regions. That's good news.

I then cleaned out the valve guides with solvent and placed the valves in them and took lateral (left-to-right) measurements of the play between each valve and its respective guide, using a dial indicator mounted to the deck of the block. Per the repair manual requirements, I performed the measurements with the valve head 5/16" above the block deck. I also checked to see if the guides were the required 7/8" below the deck. Most were, but some were 15/16" or 1" below, so I adjusted the dial indicator and valve head downward accordingly to maintain the proper distance between the valve head and the guide.

Results are that the exhaust valve total indicated readings are at or near 0.020" for all valves. Per repair manual requirements, I multiplied this by 0.44 to get the true clearance, yielding a value of 0.0088, which is well beyond the specified range of 0.002 - 0.004" for new parts, and even beyond the wear limit of 0.007".

Intake valves all had total indicated readings of about 0.008". When taking half of this, per manual requirements, the valves are about 0.004", which is beyond the 0.001 - 0.003" required for new parts, and approaching the wear limit of 0.005".

My first question is whether I am supposed to take the calculated clearances and divide by 2 to get the final answer on the clearance? Some dimensions (at least on machine drawings) are specified with tolerances expressed as "Nominal Dimension +/- Tolerance" which in this case would make the exhaust valve +/-0.0044", which would be a much closer to being reasonable. The intake would then be +/-0.002" which would be right within specs. I realize this is not likely the case, but I am asking, just so I can be sure before deciding to replace the guides. Also, I have to wonder about this because I am surprised the engine runs as well as it does with clearances like this. Hopefully my question is clear.

Second question is: If the 0.0088" for exhaust clearance, and 0.004" for intake clearance, are correct, then I don't suppose it's reasonable to expect the valves and seats to last a whole lot longer, is it? Also, if these clearances are correct, then it may explain the deposits on the intake valves. They may have been sucking oil through the guides, and the appearance of the deposits is oily. By the way, since the rebuild, the truck has only been run about twice on gas that was older than 2 weeks old. Those couple of times, the gas was probably about 2 - 3 months old, and it only ran a few minutes. The remaining hours/miles were put on with fresh gas, as I was driving the truck every day as my only means of transportation for over a year.

Thanks again.

[Charles Talbert]

I think your first calculation for valve / guide clearance was correct.

I would replace the guides, as close as you are with access, it's kind of a no brainer.

What you have found would most definitely cause the irregular seat / valve contact surfaces you have noticed as the valve can wobble around in the guide rather that work straight up and down as it should. Once new guides are installed at the correct height, you will need to lap reasonably to get valve / seat surfaces mated correctly. It probably is not to a point of needing to cut the seats and grind the valves again to fix it, lapping some will verify that so you can make the correct decision.

Running gas that was 2-3 months old will cause the issue I described earlier. I have seen valves stuck tight with only 15 minutes of idling on stale gas. This is a potentially serious issue. It's easy to eliminate by not letting gas go stale in the tank, but I'm telling you, it will become serious before you know it, then you will be doing a full on intake valve job again for sure.

[Matt Wilson]

Thanks, Charles. I will begin working on the guide replacement, and will try the valve lapping. Hopefully it will not require too much lapping to get a good fit. If it does, I suppose it may not be the proper solution. I may continue to look for a shop with a portable grinder and someone who will come to the house to do the work, as that still sounds like the preferred solution. And I will certainly ask to be sure it is a 3-angle grind.

Looking through the repair manuals, it appears that the guide replacement is something I could do myself. Can you comment on pitfalls or speciall attention needed? The main concern I would have is how hard I have to strike with a hammer against a drift in order to get the old guides out and new guides in. I am paranoid about cracking the cast iron block. I will use a brass drift. Is there any prep work that needs to be performed to the block bores or the OD's of the new guides to ensure proper fit? The manual only mentions a basic cleaning.

I see that NAPA has new guides on their website, p/n's SEP VG419 and SEP VG420. Since the originals were the same for intake and exhaust, I'm guessing the different part numbers from NAPA must mean that they are already reamed to size. You mentioned that new ones come this way. You also mentioned that you still make it a point of running a reamer through them to be sure of the correct ID. Is it worthwhile for me to find a reamer somewhere and do the same? Perhaps I could take the guides to a shop to be reamed, but I don't know if that will yield the correct ID's, since they would not be installed in the engine with whatever effect the interference fit would have.

By the way, I called VPW and asked about valve spring orientation with regard to the springs that came with the hi-perf cam, and they said there is no preferred orientation, as the springs are the same from one end to the other. When looking at the stock factory springs, is it obvious to the eye that there is a difference?

Thanks once again.....

[Charles Talbert]

Thanks, Charles. I will begin working on the guide replacement, and will try the valve lapping. Hopefully it will not require too much lapping to get a good fit. If it does, I suppose it may not be the proper solution. I may continue to look for a shop with a portable grinder and someone who will come to the house to do the work, as that still sounds like the preferred solution. And I will certainly ask to be sure it is a 3-angle grind.

Looking through the repair manuals, it appears that the guide replacement is something I could do myself. Can you comment on pitfalls or speciall attention needed? The main concern I would have is how hard I have to strike with a hammer against a drift in order to get the old guides out and new guides in. I am paranoid about cracking the cast iron block. I will use a brass drift. Is there any prep work that needs to be performed to the block bores or the OD's of the new guides to ensure proper fit? The manual only mentions a basic cleaning.

I see that NAPA has new guides on their website, p/n's SEP VG419 and SEP VG420. Since the originals were the same for intake and exhaust, I'm guessing the different part numbers from NAPA must mean that they are already reamed to size. You mentioned that new ones come this way. You also mentioned that you still make it a point of running a reamer through them to be sure of the correct ID. Is it worthwhile for me to find a reamer somewhere and do the same? Perhaps I could take the guides to a shop to be reamed, but I don't know if that will yield the correct ID's, since they would not be installed in the engine with whatever effect the interference fit would have.

By the way, I called VPW and asked about valve spring orientation with regard to the springs that came with the hi-perf cam, and they said there is no preferred orientation, as the springs are the same from one end to the other. When looking at the stock factory springs, is it obvious to the eye that there is a difference?

Thanks once again.....

I would lap in lieu of grinding the seats again unless they are just too bad. Every bit of material that is cut from the seat shortens life expectancy. Lapping will take a very minimal amount. Of course if you find out recutting is the only way, then so be it.

Guides are cast, they can be broken easily if you don't use correct tooling for driving. You will need a guide driver with a pilot of the correct size. Goodson tools is a good source for valve tools in general. You will have to drive them pretty hard, they are a tight fit. Using a driver will keep your strikes square on top of the guide greatly reducing the chance of damage. No prep necessary other than cleanliness. A wire bore brush does a good job.

The part # difference is the ID bore. Whether you invest in 2 reamers of the correct spec to verify guide bore is up to you, like I said we always do that just to be safe. Reamers are also available from Goodson. The main concern is that sometimes burrs left behind from the driving process need to be removed; reaming takes care of that precisely. Reaming prior to installing the guides is not effective and will be of no use.

[maineSS]

You will be well rewarded by spending whatever time and effort needed to get your valves seated correctly, as this area is about the most critical for power production in the entire engine.

Generally, the intake valve will flow only a third or less of the total flow capability of the intake port, and the radius formed by the valve angles and valve seat greatly influence how the fuel/air mixture enters the engine. Most of the time and money spent on a professional porting job will be spent on the valve job and bowl work, it's not unusual to see 10-15 hrs in a top-level race engine valve/seat prep.

If your valves fail to seal due to inaccurate machine work or insufficient spring pressure for the cam, you'll also lose bigtime, and the 230 doesn't have lots of extra HP to throw away. I would be skeptical of buying a cam without knowing its airflow requirements at its peak torque/HP ranges, as you're likely to be disappointed, especially with a flow-starved engine like the stock 230. In order to make more power at reasonable rpm, you need airflow, which means more intake and exhaust flow, and you won't get that out of the stock 230 without work on the head, intake & exhaust.

You should be very demanding about your valve work, only the highest standards of accuracy are "good enough", and you should let the machinist know you will expect that, and will check up on his work.

[Matt Wilson]

Ok, I've got guides on order from NAPA, and will order tools shortly from Goodson. The driver is reasonably priced at about $20.

MaineSS, that is good info. I didn't realize valve work was so critical to production of power. If I ever have valve work done again, I will be paying close attention to the work performed. I thought I had paid close attention this time, but I obviously missed the improperly fitting guides. Also, this being my first full-up rebuild, there were obviously things I wasn't familiar with. The machinist I used came highly recommended, and was not cheap. I like getting high quality work and products, even if I have to pay more for them. Unfortunately, as in this case, some times you don't get what you pay for.

I wish I had more info on the cam. It's one that VPW sells quite a bit, I think. The most I know is that it is supposed to help with the upper end, but I don't have torque curves, and I don't think VPW does either. Knowing a little more nowadays, I realize that while I may (or may not) have gained power on the upper end, I may have lost some torque on the lower end. For now, the cam will stay in the engine. I have thought about putting the truck on a dyno to see what the HP and torque curves look like, but of course, I don't have a baseline with a stock cam for comparison. The closest I would have are the factory curves.

[maineSS]

The problem with performance cams for flatheads is that most were developed for racing cars, and the torque and rpm ranges are higher than what you need to motivate a heavy truck, especially from a dead stop.

The 230 had an "early" and "late" truck cam, the "early" had a max torque rpm @ 1300, the "late" cam's max torque was at 1600 rpm. The "early" cam was used up to the early or mid 50's, depending on whose info you go by.

For higher road speed, you need your torque up around 1800-2000 rpm to use an overdrive or higher rear end gears effectively. Above 2200 rpm, the 230 really starts sucking fuel, so cams that make power over that really aren't practical for road use.

I posted specs from two different grinds here on the forum, along with computer engine sims on the "early", "late", and two grinds. The "late" model was the best of all four, had I known that, I wouldn't have had it reground to the "400M" spec.

Delta Camshafts will spec your cam for a very modest fee if you send it to them (about $10 when I had it done). They make their money by regrinding your cam, so you have to resist the sales pitch...