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Discussion Starter · #1 · (Edited)
Well some of you may have followed my ordeal with the oil consumtion of my 383. After 1000 miles on a fresh rebuild (#1) it went to the shop for a complete rebuild. There is 500 miles on the new rebuild (#2) and I am having exactly the same oil consumption issues despite the bores being checked and the correct hone being done. Looking at my records after an oil change (oil black contaminated by blowby) it looks like I used 6 qts give or take in 500 miles and I just talked to the builder (he is going to troubleshoot...leakdown test, cold and hot compression etc) but off the top of his head he is puzzled and never had a problem like this. His guess is I have a bad block casting and experiencing cylinder wall distortion when the block heats up. It is bored 040 over. Without further troubleshooting looks like I may need a new block to swap over the top end and rotating assembly to. :(

I guess ideally block should of been sent out and paid the $80 to get sonic tested.

Also I was researching the casting 3932386 1969 4 bolt 350, 2 bolt 327 or 4 bolt 302. Originally I was led to believe it was the 4 bolt 350 and when my builder told me it was only 2 bolt I did not think much of it until now I realize it originally was a 327. Since it is 040 over and stroked is their any difference between an equivalent 350 block ?
 

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oil burner

You need to find another machinist, I have worn out motors that don't use that kind of oil.What ever the problem is it should be easy to spot.How much blow-by does it have,do the valves have oil build up on back of valves,how bad does it smoke .Are the rings to loose or to tight in the pistons.302,327 and 350 same bore different stroke. Early 327 small journal crank. How about some pictures
 

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Discussion Starter · #3 ·
SDLuck said:
You need to find another machinist, I have worn out motors that don't use that kind of oil.What ever the problem is it should be easy to spot.How much blow-by does it have,do the valves have oil build up on back of valves,how bad does it smoke .Are the rings to loose or to tight in the pistons.302,327 and 350 same bore different stroke. Early 327 small journal crank. How about some pictures

Engine is still in the car. Different machinist/builder the second time but same exact problem. Went through entire engine and only thing he can think of is the cylinder walls too thin, maybe this block couldn't take the 040 over- may be a bad casting. Smokes a little at idle and if you rev at idle also during driving you notice a cloud burst when you shift. He is going to troubleshoot to confrirm that this is the potential problem.
 

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y2k600f4 said:
Engine is still in the car. Different machinist/builder the second time but same exact problem. Went through entire engine and only thing he can think of is the cylinder walls too thin, maybe this block couldn't take the 040 over- may be a bad casting. Smokes a little at idle and if you rev at idle also during driving you notice a cloud burst when you shift. He is going to troubleshoot to confrirm that this is the potential problem.
If you ever make it down my way, I have a 10054727, 5.7L 2-bolt, 1-pc. RM seal, std. bore. You can have it. Heads, too, if you want them. Throw your junked parts (from 1st. time- not your good parts you're now using) in the trunk for me.

This is just to say I'm thinking is the same thing you and your current builder is thinking: Bad block casting. Core shift can get you- even when the outer indications look OK (like the cam hole compared to the boss, lifter holes to their bosses, etc.).
 

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I would try to find a block that is bolt main, std. bore and in mint shape- or just buy a new one. DOn't even overbore it, run a std. 4" bore and a 3.75" stroke- you lose a few cubes but gain a little better ring seal and don't have to sorry about core shift.
 

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Discussion Starter · #6 ·
:(
cobalt327 said:
If you ever make it down my way, I have a 10054727, 5.7L 2-bolt, 1-pc. RM seal, std. bore. You can have it. Heads, too, if you want them. Throw your junked parts (from 1st. time- not your good parts you're now using) in the trunk for me.

This is just to say I'm thinking is the same thing you and your current builder is thinking: Bad block casting. Core shift can get you- even when the outer indications look OK (like the cam hole compared to the boss, lifter holes to their bosses, etc.).
Cobalt...thanks for the offer ! Hopefully my builder will make it right. However he has been talking to some collegues and one says the problem was that he used Rotella T SAE30 for break in (Zn for cam); that he had the same problem that Shell changed the fromula to a semi-sythetic (as we all know sythetic not good for ring seals) but I told him I disagreed and heard nothing of the sort and that others use Rotella T (mostly 15W40) for break in with no problems...but he insists to try and seat the rings with conventional motor oil. He is going to do his thing (compression tests, leak down...before and after) I guess I will let him do his thing, but I am sure the engine is going to come out again
 
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