Quote:
Originally Posted by PAUL K
Finally had a chance to watch the video. Attention needs to be paid to the exhaust ports if one wants to make big power with a d-port head. This isn't breaking news it's always been that way. Pontiac figured it out in the mid 60's.
Curious what folks opinions are with a trade trading power for conviencece when deciding between headers and manifolds?
With tuned collectors the headers would've been good for about twenty horsepower and two tenths at the track.
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I agree, there was 20 HP improvement left on that engine with header tuning, on a really hot day I would expect the RA manifolds to loose even more power versus Morris’s climate controlled shop, and the octane required might start to climb on the manifold combo to. At 3700 RPM the RA manifold combo made 417 HP and 590 TQ, and the headers was 442HP and 628 TQ. That is a 25HP/38TQ difference, and probably gets worse when the pull starts earlier yet. It is also where a street engine spends most of its life. It must have had lot of a lot of intake reversion to create that much difference at 3700 RPM, probably needed a RPM intake for the RA manifolds?? If that engine was brought to our shop to install the engine you would have to tie me to a chair to let someone put exhaust manifolds on it. LOL