[31fordcoupe]

Hey gents,

Is there any mechanical issue that you can see that would prevent the use of log style big block Chevy manifolds being mounted upside down and forward for a turbo build?

The turbo will not be directly mounted to the exhaust manifold so it / they will not bare the brunt of the weight. Just trying to see if there was anything I was missing that would prevent me from taking stock exhaust manifolds like this one and mounting them upside down with the exhaust outlet pointing forward.

1973-1975 BBC 454 LH & RH Police Interceptor Exhaust Manifolds 353030 3994045 | eBay

I was also thinking, if I can use these, to maybe cut the cast iron between each exhaust port to help with expansion and contraction issues (I have seen that done before), but didn't know if it would weaken the overall manifold design to much / more than it would help with expansion and contraction.

Thanks in advance for your responses.

 

[31fordcoupe]

Thanks for the reply. I am actually using a PT106. It's going in a 1984 1/2 ton Chevy Truck so I have tons of room under the hood.

 

[ap72]

$250 for crappy manifolds? I'd just find a set of hugger or shorty headers, and make those work, you'll have an easier time making power and they're cheaper. the ONLY drawback is that they MAY not be as durable as cast iron manifolds- then again they could end up being just as good depending on what you buy and how it built.

Heat can kill any manifold or header so don't think a cast iron one will be bullet proof.

 

[31fordcoupe]

$250 for crappy manifolds? I'd just find a set of hugger or shorty headers, and make those work, you'll have an easier time making power and they're cheaper. the ONLY drawback is that they MAY not be as durable as cast iron manifolds- then again they could end up being just as good depending on what you buy and how it built.

Heat can kill any manifold or header so don't think a cast iron one will be bullet proof.

Who said I was buying those particular manifolds? I just used that pic cus it was the first one that popped up. Chill.

I can pick up a set for $40 bucks locally so I just wanted to know their viability. I also never said they would be indestructible; again just wanted to know if they could be configured correctly.

 

[31fordcoupe]

Thanks hcomp.

 

[S10 Racer]

They will not bolt up upside down.

 

[OneMoreTime]

If all else fails I can take a exhaust manifold gasket or make a pattern and take it to my laser cutter guy and have a manifold flange made and then get some ready bent tubes and make an exhaust header that fits my particular needs. Sometimes guys try to save some cash which is fine but then wind up screwing themselves..learned that lesson..

Sam

 

[31fordcoupe]

Ok thanks a million for the replies guys. Guess that answers that question. I just didn't want to spend $$$$ on an aftermarket header designed for turbo applications.

I do have a good wire feed but just not that good at using it yet. Good friend of mine is an expert welder so I guess we will just get a good kit and get after it.

Thanks again.

 

[cobalt327]

They will not bolt up upside down.

If you swap them side to side and THEN flip them upside down, I believe you'll see they bolt up.

The outlet may not be where you want it. There may also be a slight mismatch between the manifold and head ports, but this can be taken care of w/a die grinder and/or slotting the holes.

 

[31fordcoupe]

Cobalt,

As alway I appreciate your insight. Looking at the manifolds if I switched sides and turned them upside down, wouldn't one collector be facing upward and the other collector facing forward with a slight upward tilt? Please correct me if I'm looking at them incorrectly.

 

[cobalt327]

Cobalt,

As alway I appreciate your insight. Looking at the manifolds if I switched sides and turned them upside down, wouldn't one collector be facing upward and the other collector facing forward with a slight upward tilt? Please correct me if I'm looking at them incorrectly.

Like I said earlier, the outlets might not be where you want them...

 

[S10 Racer]

I tried switching block hugger headers for the BBC S10 I built and the ports are too far off to correct with a die grinder. I actually cut the flanges off the tubes and flipped them 180* and welded them back on to get them to fit. Not saying it's the best way but I didn't want to fork out $1500.00 for a set of Lemon headers. The way mine came out, it would be so easy to install turbo's on.

 

[cobalt327]

The ones we did in the boat were off by about 0.110" before being reworked. I doubt the outlets are going to work for him like that anyway.

 

[454C10]

chevy 454 turbo manifolds | eBay