This would circumvent the fact that I'm teaching my 17 yo on his first build. He's a really smart kid and deserves this particular challenge. Also a stock crate job is not what is required here. We chose this motor because it produces monster torque at low rpms. since no one these days is into torque because they only see rpms they would normally not consider that worthwhile. But opinions based upon ignorance are rampant.
CK5
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TBI Heads cc?
- Thread starter jimmy'sjimmy
- Start date
This would circumvent the fact that I'm teaching my 17 yo on his first build. He's a really smart kid and deserves this particular challenge. Also a stock crate job is not what is required here. We chose this motor because it produces monster torque at low rpms. since no one these days is into torque because they only see rpms they would normally not consider that worthwhile. But opinions based upon ignorance are rampant.
Good luck on that rebuild. This is the all new swirl port TBI crate engine I put together not too long ago, after crunching the numbers on rebuilding my old swirl port TBI engine with the crack prone fatigued heads would be about $2200.
I did keep my old 1991 TBI 4-bolt main block though (the heads went to the metal recycler). I am thinking of making the block into a 383 stroker, and then getting a set of aluminum swirl port heads that both Edelbrock and Summit Racing make for it. Those heads are a much thicker casting than the GM factory crack prone swirl port heads, and come with 1.80 EXH and 2.02 INT valves. They also come with screw in rocker studs, unlike the factory GM heads. I would have to change out the valve springs those heads come with because they are for flat tappet cams, and not roller cams.
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Funny that no one has any information on these heads yet you say they are crack prone. Do you have informa
In order to lower costs all of GM's factory heads from the swirl ports to Vortecs have a thin castings that crack from metal fatigue once they get about 200,000 miles are so on them. 76cc TBI heads with stock type flat top pistons yield about 8.75:1 compression. The 64cc TBI heads with stock type flat top pistons yield somewhere in the range of 9:1, but I have seen specs posted on the 64cc heads that range from 9:1 to 9.25:1, and even 9.5:1. It is hard to nail down some of GM's specs sometimes. After market heads do not suffer from wanting to lower costs, thus the cast thickness is about double what GM heads have. The set of Edelbrock heads I want to buy will probably out live me .
Another thing that kills GM heads is press-in rocker studs. After a lot of miles most heads have some oil start to seep through the valve guides. The small amount of oil that ends up on top of the piston creats a small amount of hydraulicing. This hydraulicing, thus causes the press-in rocker studs to push out of their bore. This in turn causes the valve lash to come loose, thus flatening the cam. After market heads with screw-in rocker studs do not have this problem.
Another thing that kills GM heads is press-in rocker studs. After a lot of miles most heads have some oil start to seep through the valve guides. The small amount of oil that ends up on top of the piston creats a small amount of hydraulicing. This hydraulicing, thus causes the press-in rocker studs to push out of their bore. This in turn causes the valve lash to come loose, thus flatening the cam. After market heads with screw-in rocker studs do not have this problem.
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Ive
I've done 53 hours of research on these heads where are you getting your info? Nothin I have read or heard from 5 different heads builders have pointed at this information. None of GM stock heads past a certain year were heavy cast so is safe to say that hind site is 20\20 on the valve stems.
There is 0 definitive data on these heads. I'm looking for facts not fictional opinion or heresay. Offering an opinion is about as usefull as teets on a bull. Because as for the pros they are split 50/50 aparantly.
As for the stock rocker studs pullING out that generally happens when someone uses cams with higher lifts than the head was designed for as well as attempting to pull 55k from a head designed for 4500
I've done 53 hours of research on these heads where are you getting your info? Nothin I have read or heard from 5 different heads builders have pointed at this information. None of GM stock heads past a certain year were heavy cast so is safe to say that hind site is 20\20 on the valve stems.
There is 0 definitive data on these heads. I'm looking for facts not fictional opinion or heresay. Offering an opinion is about as usefull as teets on a bull. Because as for the pros they are split 50/50 aparantly.
As for the stock rocker studs pullING out that generally happens when someone uses cams with higher lifts than the head was designed for as well as attempting to pull 55k from a head designed for 4500
The studs on my 84 350 with 85k original miles pulled on one cylinder.
It still had 180 psi on all cylinders.
It was babied all it's life, stock 2wd th400.
I towed a 10k trailer for 1000 miles and I got home and had a weird noise and found that problem.
As for the vortec in question I have nothing...
- Go back a few more years and the metal was much better. But I would say that was a manufacturing defect 1 in a 1000. I mean with any build things could just fail most of the fails I've heard of were the high lift cams without a spring change. While the stock springs can handle .550 clear
I agree it's not a trend but it can happen, just like my 10 bolt blew the ring gear at 90k miles with stock tires
