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Two things: One, I checked the cam by putting the dial indicator directly on the lifter. It may very well be one tooth off. Getting the nudge about 10° BTDC.
Two, I wondered if the oil pressure was too high. I ordered a standard pump. However, I ordered from Rock Auto. Thinking they may have shipped a high pressure/high volume because, well, they're Rock Auto.
Experts, you tell me. I slapped the valve cover back on to test oil pressure. Over 65psi when started. Didn't settle down much.
Cold oil pressure around 60 psi is normal; that's where most pumps are regulated at internally. As the engine warms up, it should go down, but no lower than about 20 psi at idle.
Cold oil pressure around 60 psi is normal; that's where most pumps are regulated at internally. As the engine warms up, it should go down, but no lower than about 20 psi at idle.
Good. That's one less thing to concern myself with.
Two things: One, I checked the cam by putting the dial indicator directly on the lifter. It may very well be one tooth off. Getting the nudge about 10° BTDC.
Two, I wondered if the oil pressure was too high. I ordered a standard pump. However, I ordered from Rock Auto. Thinking they may have shipped a high pressure/high volume because, well, they're Rock Auto.
Experts, you tell me. I slapped the valve cover back on to test oil pressure. Over 65psi when started. Didn't settle down much.
I think you're on the right track with the timing gear being a tooth off. You should see a big difference in vacuum and performance once it's right, plus get your compression where it should be.
Hopefully, the reason for the the low compression was this.
Didn't want to bet everything on it though. I made a side bet on the shims. All lifters now have right at a half turn preload. Most used a .030" shim. One used a .040" and two or three, a .020".
I would say the tooth off will have a huge effect on compression. You were overlapping the valves and bleeding off compression before the valves closed.
With the valve timing correct, the truck runs great... except I'm still plagued by the failure to idle. While vacuum jumped to 18", compression is lacking at 125-130 psi. I decided to throw in the towel and yank out the Mustang cam. I have a 1988 Crown Vic cam that is a 99% direct replacement for the original cam.
After pulling the intake, I went to crank it around to TDC. That's when I notice the engine is not all that hard to crank (with eight plugs in). With the intake closing completely at 76* ABDC maybe I shouldn't expect much resistance. But I can hear the air hissing out the intake ports. Some of you read "Machined Block". I will say here that the same guy rebuilt my heads. Valves and seats ground.
Anyway, at just 130 psi compression on a brand new engine, I'm planning to pull it. I really don't expect that the rings didn't seat because the vacuum at the PCV air inlet is way too good. Maybe I got crap work on the heads too.
Tested four cylinders for leak down, 1=25% loss, 2=30%, 4 (with some oil) 20% loss. Five showed about 5% loss with some oil. I can hear air in the crankcase on all. Five's valves were sealed tight, no detectable air. The other three, especially two, air leaking out the intake valves.
Opinion question: If you just had the head's redone professionally, valves and seats reground and assembled, how much air leakage would you say is acceptable? My opinion is none.
EDIT: On right side, 1,2 and 4 leak, 3 does not. None leak on drivers side.
Opinion question: If you just had the head's redone professionally, valves and seats reground and assembled, how much air leakage would you say is acceptable? My opinion is none.
None, this is the correct answer.^
Upon removal of the head and disassembly, it is revealed that the heads got a very poor grind job. One angle with concentric ridges cut into the seat with the odd, random burr. The second machinist I took them to said that these heads, with this work quality, should not be expected to seal.
So, I got unsatisfactory work, nothing more. Now moving forward.
Glad you found that problem out. It's hard to trust anyone's work anymore.
Plus, what they want paid, for their, crap shoot work, then the money spent, to have it re-done, and gaskets, fluids, plus, your time, to tear it BACK! apart, and throw in, what if its how you make your living, just like them, now your waiting again, and how much that cost you, that you cant recoup, they dont care...never have...never will
Just this past summer, I had this 'ol boy that has been doing it for almost 50 years, bore the block 0.030" (93 5.0 roller), and clean it, plane the heads 0.010", and valve job. Also polished the crank as it did not need machining. It cost me $750. But it took him over two months to do it as he only worked on it when he felt like it. However, I brought the parts home and put everything back together with some new goodies of course and turned the key and it fired up only needing to twist the distributor a bit. Now I say all that to say this. I am not a super mech. and by no means a fast one but I do know I didn't have the energy to tear that thing apart again. My friends gave me a hard time for the machinist taking so long but I knew his work would be great when completed. I really don't know if I paid too much or too little but it is worth every penny and the time waiting for it to have it done correctly by someone you have confidence in.
Basically, I just wanted to say that there are still good machinist out there as well as some you can trust.
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