Hello friends,

I have been chasing the zero oil pressure at idle on my Bird for a while, already opened before threads for my opti rotor and cap issue and now I have a little more time to spend for engine rebuild because of this oil pressure problem which persists for a while.

The whole engine has been pulled from the car and now I see the problems with the camshaft bearing, first on the camshaft housing was literally fell out, the second one deformed and latter are on their positions when we removed the camshaft.

The main problem so far is the damaged cam housing at the entrance from camshaft moving because of the bearings and now I contacted you to find out the info which diameter is of cam housing where the bearings come in, in order to find out what is the best possible scenario to fix an issue and remain in the GM engine ervice manual specifications.

​​Also, the camshaft doesn't looks so god, so I'm in a chase to buy another one with stock specs, don't plan anything to tune, because all of the stock parts are on the engine, 56k miles so far, want to replace with another stock parts if it is possible.

Which parts do you prefer as necessary for rebuild? I have already bought the gaskets, engine workshop will inspect the engine block and heads and with measures to buy a new crankshaft bearings, I suppose new piston rings, new connecting rod bearings and to find out what is appropriate for camshaft bearings because of this problem with the little damaged cam housing.

If it something important, I suppose many other things which I don't know yet, just be free to inform me and I will pay attention to the details and work best as possible in order to complete this rebuild very well.

So far, inspected pushrods, valve rocker arms, valve lifters, pistons, connecting rods, oil pump, everything looks fine and on its place.

If there is necessary and important to buy a more new parts to replace especially for this case, I will do it without any hesitation, what has to be done will be done, no doubt, I have an enough time and a solid amount of budget for this, so not a problem.

Thanks in advance, big greetings from Europe,

Nikola

 

Are you aware of this book:

"Small-Block Chevy LT-1/LT-4 (sic) Engines" Should be "LT1/LT4", no hyphen.

"Step-by-step rebuild to factory specifications. Covers 1992-1997 GM cars and trucks."

Mike Mavrigian
HP Books ISBN: 1-55788-393-9


Can't believe the price US$69.99. When I bought it 25+ years ago it was US$18.95

Just a caution.... this website is almost "dead". There are maybe 6-10 knowledgeable members who come here occasionally. Might take a while to get answers. I try to answer most posts, but in this case, I have not rebuilt a stock engine. I had a shop build the high performance engine described in my signature.

 

Given the motor is completely disassembled now but had low milage for a 26-year-old motor, send block to machine shop for mic and if all checks out have the cyl hones, rods resized with ARP fasteners, crank polished and new bearings and new rings. The machine shop can install new cam bearings and freeze plugs. Replace cam housing

Heads get a valve job and new valve springs and valve seals. Many would advise on an aftermarket cam but if you want to stay stock, I assume GM has new stock cams available. It is always recommended new lifters (look into Lunati) with any different cam than what was in the car. stock PR may be straight but going 5/16 with .080 thick walls would be prudent. Confirm any of your rockers are not galled.

Get a 1 piece oil pump shaft as the stock one with plastic collar is prone to breaking on re-install because of aged plastic collar.. A standard Mellig oil pump is fine. Some swap out the spring to the "high pressure" one.Be very carefull installing the oil pump drive gear relative to torque tightening (just hand snug using loc tite) as the plastic aged is prone to cracking if to tight

Your injectors are likely fine but given the age sending them out for cleaning and testing is a good idea. You get a B/A sheet on flow.

 

Thanks Fred for your fast reply as usual, I will buy a kindle version to add valuable details to service manual which I already have.

Okay, I understand, you and just a couple of people are still active, thank you very much

 

Thanks a lot Chim for your fast reply also, will be done that as you said. Stock fasteners I suppose are not recommended for re-use again, as I don't see any thread damage on them. Okay, understood, will check for freeze plugs. The cam housing where the camshaft enters in the centre of the block don't know how to fix it and didn't know that part can be changed, i thought about some work at the workshop with their suggestion.

I will try to find out the same one stock GM cam, because I don't want to change lifters, since they are stock ones and very fine, in good shape without any bad sound and noise even with this zero pressure problem and also visually without any damages. Will inspect for rockers, great suggestion. What did you mean for pushrods, replacement, didn't understand you for that very well?

​​​​​​Okay, will find it, if you suggest Melling or some other oil pump or just shaft, be free to tell which one precisely is the best one from your experience and knowledge.

Injectors were replaced whole set last year, they are in great shape, also put a couple a days ago a new ACDelco fuel pump because of the bad check valve in stock one.

 

Saved oil pump recommendation from the old days:

Melling Select 10554 pump (std vol, 3/4" inlet. Should come with Melling IS-55E shaft with metal coupler and 70# pink spring).
GM pickup tube, 12550042 (3/4").
GM oil pump drive gear 1103868 (if needed).

Oil pump may have changed design since then.

I haven't been able to figure out what the "cam housing" means. Is there a picture?

 

Thanks a lot Rob for jumping in the thread and help, I will do like you and Chim said, will buy the Melling standard volume oil pump version and oil pump metal shaft guide.

Since I'm not American and don't know every your words and phrases in communication here, I am using occasionally a translator for some words to figure it out and send you.

The problem is with the damage on the entrance where camshaft comes in the block, the first two bearing almost fell out and the camshaft was loose because of that and have a some undesirable movement in the block while car was driven and damaged the housings/sockets where the bearings come in, the first two are in the problem, the third, fourth and fifth are fine, I don't know better to explain with my English, don't know how you call it precisely. I'll attach the pictures just to better understand what is the main problem to solve now and what is the best possible to do in this situation?

Thanks guys for help a lot, all of you!











​​​​​​​

 

I would get an opinion from a competent machine shop on the cam bearing journal surfaces. They can measure the bores and inspect the damage to see if there is a real problem that can't be remedied.

 

Okay Rob, thank you. I was searching for cam bore diameter measurements, but haven't find anything so far, only found for the LT1 V gen engines.

I found the cam housing bore diameter measurements when searching on RockAuto and Enginetech site for cam bearing specs for a listed options for our engine. I find something, maybe that can be useful information for machine shop.



If you or anyone knows any of these info, please let me know, because machine shop asked me for that info since they didn't know that measurements also, but I didn't know to tell them. Hope to resolve this unpleasant issue soon and continue to progress with the repair process further.

 

If nothing else, a shop should be able to measure any of the bores that have no damage and use that to compare.

 

Thanks for help Rob, I contacted them a couple of hours ago and provided them the cam bearings measurements so they can compare with the cam bores in the block and figure it out what is the best solution.

In the meantime, if anything you remember and have it on your mind, some good tips and hints like replacing some parts during this engine rebuild process, since it is easier now to access to everything because of disassembled engine, anything important that you and others have on your mind, just type me here, it would be very precious, I really appreciate it.

 

The rebuild book Injuneer noted is VERY complete. I would encourage you to read it several times. The gen 2 LT1 is different in some aspects compared to regular SBC. One note is about the ball bearing in the oil galley, rear under one of the main caps IIRC. It needs to be removed to properly clean block but more importantly, need to be put back in

 

Thank you Chim for your participating, I'll read the book a couple of times which Fred suggested, looks very detailed and rich with many valuable information.

Okay, understood, I'll tell the machine shop to pay attention on ball bearing in the oil galley, to do that cautiously, precisely and thoroughly.

If anything else you remember in the meantime, whatever you think it's important to do or replace during this work, just reply me to note that and pay attention. Thanks in advance one more time.

 

Do you have a copy of the 1996 factory service manual? If not, it can be downloaded here, courtesy of member GaryDoug:

https://www.mediafire.com/?40mfgeoe4ctti

On page 6A3B-53 it does have some camshaft data, including journal diameter, end play, lobe lift. But that's all. However there are detailed assembly procedures.

 

Thank you very much Fred on your help as always. I have a service manual, printed from PDF, easier to look at the paper form and work.

I found a measurements for a whole bunch of things and I think it will be more than enough, now should concentrate on your advice for LT1 book on kindle and search if there's more valuable and detailed information about whole procedures in rebuild.

In the meantime, if anything comes to your mind, some useful tips and hints from your abundant knowledge and experience with these cars and engines, please let me know and note what to pay attention for some parts to replace and anything else you think that would be important for this work, it will be very useful to me, thanks in advance.