Bernhard

I have a few Questions about the 69 442 exhaust manifolds?


Do they flow as well as the 70's X Z ?
What letters are on then right and left manifolds?
How rare are they and going rate for a nice original set?
I thought I had a set still form the 80's but have not been able to locate them in storage.


Has anyone done a quality header performance comparison, against the W Z manifolds?

rcktdoc

First off 70s are W and Z,as are 69,but 69 drivers side is 69 only and has a heat riser flap. Expect to pay 350.00 plus for a perfect pair. 69 thru 72 are divided between the center exhaust. We did a test with the reprodution 2 1/2" exits and lost 50 Hp 50 Tq after changing from headers and that was on a 408 cuin,expect to loose more with the factory manifolds.

Greg

Bernhard

Thanks for the reply Greg
That is very good info and that is a big loss in hp/tq.
Was the test on a engine dyno or chaise dyno?
Are you running headers or manifolds on your car?
How do you think a X pipe would impact the exhaust manifolds compared to the headers, would the X pipe be a wash or would the exhaust manifolds gain back some of there performance loss?

455man

The X pipe helps but not as much as the headers do. I've heard like 5-10 hp gain from the X pipe.

oldsmobiledave

http://realoldspower.prophpbb.com/topic4862.html

Bernhard

Thanks Dave more good info on the subject.
75hp on a big inch engine ouch.

rcktdoc

That was on an engine dyno.The Xpipe may help but not much,the factory exhaust manifolds are very restrictive and we had the ramair reproduction manifolds. Right now it has the exhaust manifolds and the engine is a small block. Just imagine how much loss there would be with small block exhaust manifolds.

Greg

Bernhard

Thanks for the reply Greg.


What do you think about a merge collector spike just after the exhaust manifold in the pipe?

rcktdoc

I think the only thing you could do to improve the exhaust manifolds is get rid of them.

Greg

70cutty

x2

455man

I dont have manifolds on any of my Olds. I'd just go to headers if you want the power. Small blocks are not that bad to put on. Big blocks are a little tighter.