The machine shop just called and said the line bore was out by .010. They're honing it and it should be ready in the next day or two. Hopefully I'll put it together this weekend.
Just to voice another opinion, in my experience with line bore problems, .010 should bind the crank to the point of either not tuning freely or spinning with great difficulty. Can't really see where it would affect any pressure loss as you have. Wonder if the machine shop is being real honest about the findings, or are covering up some other mistake and charging you for the line hone. Line honing is a very precise operation and very few places have the machine to do it, anymore. I may be barking up the wrong tree but hate to see you get bit on this. Something just does not feel right on their findings and cures. JMO
Personally I was leaning toward a cam bearing installed wrong:16suspect A rod or main bearing issue would have gotten noisy very fast. Sounds classic cam bearing to me.
I'm with OLDGUY. For a .10 core shift to happen there had to be problems with oil pressure a long time before the rebuild. I would have them put a new set of cam barrings in just in case that the line bore is not the problem. will save on a engine removal later if it does not fix the problem. Of corse you will not know if the cam barrings or the line bore fixed the problem. The end result is that the problem is no longer there. The front barring has a lot of load on it with the timing chain and the dist drive and tends to wear out. I have taken 302s apart that I have had to cut the babbot away from the barring to remove the cam. Good luck Don
Cam bearings are relatively cheap. Of course, I'll put them in. For all I know, this block ran low oil pressure before the rebuild. I pulled this from a 73 Torino and immediately took the block to the machine shop - I never heard it run before. When I put the motor together and had the problem, I first thought of cam bearings as well. Either way, it will be line honed AND have new cam bearings, so hopefully I won't have the problem anymore. I've never heard this motor make any noise - it's always sounded really good. But I haven't really driven it either. Once I saw the pressure drop I knew something was wrong and killed it. I tried a few things along the way with no success - that's why I pulled it out again. Also, the cam retainer plate is in excellent condition as the end-play is in check.
Always keep in mind that when there is good pressure cold and bad pressure warm, it will usually not be something like missing galley plugs are installation problems. I have found that in about 95% of the cases on windsor Fords that good pressure cold-bad pressure warm is crank and rod bearing clearances.
OMG so I was right . Well Im gonna have to tell the wife about this one. When I put the new crank in my block it turned freely. Thats why I didnt think it was that to begin with. I thought if it was out a little that would seriously bind a crank. After driving it down the road about 3 times the noise and oil pressure was making in apparent that the problem was coming from that area. Then after tearing it down and seeing the bearings it was pretty evident.
Dave, I didn't see this post earlier. I hope this isn't the case - I could have used the extra money. He is a well known machinist locally and builds for alot of race teams. I think I can trust him. I picked up everything last night. The block has been line honed and new cam bearings have been installed. I don't remember the crank binding when I put it together, that would have thrown up a red flag. But like I mentioned before the #3 and #4 upper half of the main bearings looked brand new while all the others had some sort of wear on them. I assume this would be caused by a line bore problem, being that it looked like a tolerance issue. I guess the other option is that the bearings were mis-labeled and the upper part of the main bearing was a standard instead of .010 under. Ideas?
Bearing deal could very well have been the problem. Wish the machine shop's here were as quick to get my stuff done. Just picked up my 347 block the other day, been at the shop for six months or better. Was getting a little antsy about it, but they are good guys and know their Ford's. Bore and deck height are dead on, as well as all other clearances etc. Check all my bearings with micrometer' or snap gauge on the cam bearings. Everything went well during assy. till I fought with the spiral locks on the pistons. If you don't do them everyday, they can be a booger till you get on to it, especially when there are two on each side of the pin. But got them all in and the rods and pistons installed(already had file fit the rings and a few other block preperations). Worst part was fitting up the main girdle and oil pump. Grind and fit, grind and fit, maybe a better quality girdle would fit better? Then the oil pan had some clearance probs, a little light hammer work and the short block is done until I decide on what cam to use etc. Hope the old 331 holds up till end of the year, have built three race engines in the past three weeks. My youngest son has been home on leave for two weeks, before deploying to Iraq. Enjoyed being with him, and his manual labor along with Todd. Hope to race against him this weekend, will mean a lot to both of us no matter who wins. Glad you have solved the problem, keep us informed how it all works out.
