Add a Comment
glad to see so much information gents, cast all the way for me then. cheers :-)
Moving to the other side of the engine, the same principles of pressure waves apply, length of inlet track can be critical to charging the cylinders. But once again only at certain engine speeds and again only applies to highly tunes engines.
It not a race car so the cast manifold supplied by ford will be sufficient.
Equal length primaries, and the length of them only relates to the way the presure pulses affect the exhaust gas. On a road going engine where flexibility and drivability is of greater use the length of inlet and exhaust primaries is not crucial, indeed on some engines they are different lengths to help spread the torque curve. On out and out race engines the lengths are tuned in line with the camshaft and cam timing to maximise the power output at specific engine speeds and often the engines perform poorly when operating outside this range.
So basically all the things I was taught about exhausts needing equal length primaries etc is useless until you apply them to a stage 2 or 3 engine?
The exhaust pressure pulses are still 180 crank angle degrees apart, flow work shows the maximum airflow either intake or exhaust is always at a point far away relatively to the max airflow of the next cylinder with regard to engines of 4 cylinders or less. 'Tuned length' manifolds help by using the positive or negative pressure waves to improve the airflow at certain engine speeds (usually peak power speed). The relatively poor performance of the cast manifold is because of its internal design/poor flow characteristics.
The pinto cast 4-2 is a very good piece of design and four branch manifolds rarely offer any great performance advantage until high levels of 'tune' are reached that accompany race spec engines. The exhaust system muffler is usually the cause of poor exhaust performance and this is usually because the OEM has to meet stringent drive-by noise limits which is most effectively achieved by restricting flow (muffling)
HTH
© 2024 Created by Tim Walker (The Bodger). Powered by
You need to be a member of DuttonOwners to add comments!
Join DuttonOwners