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Old 12-31-2012, 04:07 PM   #1
roadrunner-europe
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2/4 and 2 or 4 bolt main bearing?

Hello everybody,

after having new problems with my engine, i search some informations about this engine.
The engine # 3970014
Now i find out, that the engine did his work in a camaro and was built between 1970 and 73. This website says, that itīs either a 2/4 or a 2 or 4 bolt main bearing is? Because there is a difference?
I have to change the intake manifold gasket. could anybody tell me, if I have to install the restrictor(s) at these gaskets or not. If so, on both sides or only left or right?
could anybody tell me, if I have to use a sealant under and up the gaskets especially under these small (rubber) one at the front and the end of the motorblock.
I changed these gaskets 3 weeks ago and 3 days later iīve seen, that the small one at the end and at the front were pressed out. I installed them with sealant.

Thank you for informations

Chris
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Old 12-31-2012, 04:30 PM   #2
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Re: 2/4 and 2 or 4 bolt main bearing?

Don't use the seals. Jus a big bead of silicone. Make sure the surfaces are cleaned with ISO alcohol and dry.

The restrictors just help keep the intake cooler for better power.
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Old 12-31-2012, 07:11 PM   #3
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Re: 2/4 and 2 or 4 bolt main bearing?

You don't need to add restrictors. If it's cold, you want to heat the intake fast for the carb to work better.

Dab silicon under the intake corners. Dap around the water jackets too. Use a very thick bed on the block wall ends.
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Old 01-13-2013, 05:29 AM   #4
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Re: 2/4 and 2 or 4 bolt main bearing?

Hello,

damn, I think I installed a new bug.
I changed the intake manifold (got it from a friend), itīs a Weiand, donīt know exactly wich one. torque optimizer.
Do I generally need a cam shaft kit for weiand intake manifolds or is stock sufficient?
No more power at the moment.
max speed 25 mls/h
0-25mls/h >30 sec
urgently need info

Thanks

Greets Chris
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Old 01-13-2013, 05:41 AM   #5
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Re: 2/4 and 2 or 4 bolt main bearing?

Hey Chris,
you have to find out what intake it is exactly! When it is a high performance or race application there should be a matching cam.
But these problems sound more as if the carb settings and spark timing is completely out of tolerances!
Is there some misfiring or strong fuelsmell?
Do you have the other intake to compare or maybe forgot a rag under the intake?
Just guessing!
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Old 01-13-2013, 05:52 AM   #6
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Re: 2/4 and 2 or 4 bolt main bearing?

Hi Volker,

no, thereīs no fuelsmell, I run the car with LPG. With normal fuel not possible to keep the engine running since change. Even misfiring there is nothing.
Have worked with a friend at the engine. If I had forgotten a rag, he would have seen it.
Will go to the car now (itīs in a garage 10km away from my home).
I guess (hope) thatīs only a spark timing problem

Will report then.

Thank you

Chris
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Old 01-13-2013, 05:58 AM   #7
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Re: 2/4 and 2 or 4 bolt main bearing?

Chris,

maybe the LPG is not distributed properly?
Check the fuel system for a blocked or kinked line and the carb for debris in the jets.
Good luck - iīll wait for the report!

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Old 01-13-2013, 10:47 AM   #8
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Re: 2/4 and 2 or 4 bolt main bearing?

Iīve had luck.
It was only a spark timing problem.
Engine runs, not yet well, but rideable.
But now Iīve found a leak in the intake manifold I got from a friend (Weiand 7546). It lose water.

It seems, that the neverending story goes on. Christine lives again.
Will buy a new Holley intake manifold. "Holley Contender" Has anyone an experience with this one? According to the description itīs an intake manifold for heavy trucks and offroad-use. Power band 0-4800 rpm. No camshaft kit required.
I wonīt install the old one.
Now I have to ride my motorbike again. Cold

Waiting what will happens next.
I LOVE MY CHEVY TRUCK

Chris
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Old 01-13-2013, 03:20 PM   #9
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Re: 2/4 and 2 or 4 bolt main bearing?

hope it works for you
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Old 01-13-2013, 04:13 PM   #10
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Re: 2/4 and 2 or 4 bolt main bearing?

Quote:
Originally Posted by roadrunner-europe View Post
Iīve had luck.
It was only a spark timing problem.
Engine runs, not yet well, but rideable.
But now Iīve found a leak in the intake manifold I got from a friend (Weiand 7546). It lose water.

It seems, that the neverending story goes on. Christine lives again.
Will buy a new Holley intake manifold. "Holley Contender" Has anyone an experience with this one? According to the description itīs an intake manifold for heavy trucks and offroad-use. Power band 0-4800 rpm. No camshaft kit required.
I wonīt install the old one.
Now I have to ride my motorbike again. Cold

Waiting what will happens next.
I LOVE MY CHEVY TRUCK

Chris
The contender is an old old old design. Not that its worse than stock but it really isn't better by much. Just a regular performer from edelbrock will do the job.
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Old 01-13-2013, 09:57 PM   #11
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Re: 2/4 and 2 or 4 bolt main bearing?

It depends on which Contender you have, there were two different part numbers. You can find the number cast into the bottom of the intake. There's a 300-36 and 300-38. The 38 is a low rise mild performance intake, where the 36 is a high rise. Is is a copy of the old GM Z/28 intake without the heat riser. While it is dated the 36 is still a really good manifold, I'd say better than an Edelbrock Performer, about the same as the Performer RPM.

However, I don't know hard American speed parts are to come by where you are. If you already have either manifold I'd say use it.
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Old 01-14-2013, 12:39 PM   #12
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Re: 2/4 and 2 or 4 bolt main bearing?

Hello,

good news for me: a friend will try to weld the hairline. He has everything to do this work. If itīs works, ok. If not, I can still buy a new one.

*cross fringers


Quote:
Originally Posted by Aaron_L View Post
It depends on which Contender you have, there were two different part numbers. You can find the number cast into the bottom of the intake. There's a 300-36 and 300-38. The 38 is a low rise mild performance intake, where the 36 is a high rise. Is is a copy of the old GM Z/28 intake without the heat riser. While it is dated the 36 is still a really good manifold, I'd say better than an Edelbrock Performer, about the same as the Performer RPM.

However, I don't know hard American speed parts are to come by where you are. If you already have either manifold I'd say use it.
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Must be the 300-38, cause in the description is marked, that it is a low rise manifold.

First waiting till saturday, then we will try to weld it.

Last edited by roadrunner-europe; 01-14-2013 at 01:04 PM.
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Old 01-14-2013, 01:03 PM   #13
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Re: 2/4 and 2 or 4 bolt main bearing?

Quote:
Originally Posted by INSIDIOUS '86 View Post
The contender is an old old old design. Not that its worse than stock but it really isn't better by much. Just a regular performer from edelbrock will do the job.
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Hi

Problem of this solution, in the catalog of my spare part dealer is written, that i need a camshaft kit, a spacer under the carb and at least a 750cfm carb.
Will even work w/o it, but not so good.
Donīt know why.
And the Holley manifold is to be better than the stock and will perform better than the Edelbrock w/o tuning kit.
Am I on the wrong way?
Cross fingers for saturday. Will weld the broken Weiand. The engine runs very well with this.

Thank you
Chris

Last edited by roadrunner-europe; 01-14-2013 at 01:11 PM.
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Old 01-26-2013, 09:40 AM   #14
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Re: 2/4 and 2 or 4 bolt main bearing?

Hello,

the welding of the intake manifold has been successful. No more water leak. But now I lose a lot of oil instead. It comes from the rear side of the engine. Takes its way down along the gearbox. Valve covers are tight.
Now my question: is there an oil passage in the distributor to the top of it?

the problem is that the new distributor has a narrower foot than the new one and the clamp, that hold the distributor on the intake manifold, is a little bit to large, whereby the clamp slides over the foot.
Is it possible that I lose oil over the distributor foot. I canīt see anything. After cleaning the engine, I drove out for a testdrive. after returning in the garage, take a look at the engine: in a sink of the manifold under the distributor a lot of oil. Where does it come from? Large oil stains on the floor within 5 minutes after the engine was turned off.
I hope, I explain myself good enough.
Need urgent help.

Greetings Chris
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Old 01-26-2013, 10:57 AM   #15
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Re: 2/4 and 2 or 4 bolt main bearing?

hello Chris,
a picture would help!
Maybe it is from the oil pressure sender?
If the distributor doesnīt fit in right it may cause that leaking. It drives the oilpump!!
There is also a possibility that the oil squezes throug the screws in the intakemanifold if they are not screwed in with sealer!
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Old 02-09-2013, 03:40 PM   #16
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Re: 2/4 and 2 or 4 bolt main bearing?

Hi everyone,
work is done, ride out for a testdrive this evening. Seems that everything is tight.
Have changed the shaft sealing ring at the rear end of the engine today. Found a leak there last week.
The oil on the intake manifold came from the foot of the distributor. The point at which the screw holds the clip, is 3 mm higher than the point on the standard intake manifold. It was firm enough to hold the distributor on the good timing position, but not enough to press it downwards.
Now I even know, that it is a ī70 two bolt Camaro engine.
Thanks to everybody

Greetings Chris
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