Yates heads

[scott]

Anyone here running "yates" heads? Anyone care to postulate on a minimal displacement for running these heads on the street?

[Kevin M]

The Yates heads come in several varieties and a number of different port sizes. They can be had in intake port volumes as low as 215cc, although they really come into their own at about 235 – 250cc. Check http://www.chapmanracingheads.com/p_home.asp for an overview of what is available.

Head sizing is based on Engine size and RPMs. A 302 @ 8,000 RPMs needs the same head as a 402 @ 6,000 RPMs. Yates heads are also normally used with the 9.2” SVO deck height blocks. Using them on a 9.5” block will require fabricating manifold spacers among other things.

What sort of RPMs and usage did you have in mind?

Kevin

[scott]

Would like to use them on a 8.2" deck 347 on the street. RPMs of 7500 max and then only occasionally (my bottom end will definitely take this RPM). I think victor jr's may be a better street choice but am somewhat taken w/ the idea of using these heads. I'll look at the URL you posted.
Scott

[Kevin M]

Scott,

Yates heads are far from a simple bolt on. They are designed for Winston Cup motors which run 9.2" blocks. On an 8.2" block you would have to come up with your own intake manifold for starters. This would not be a project for someone who is not experienced building racing motors and doesn’t have access to a machine shop.

For what you have in mind I would look closely at the AFR 205 and 225 Heads. The Yates could be made to work if you really keep the motor in the 6,000 - 7,500 RPM band, but would be probably be no better than the AFRs up to 6,500. Check AFR at http://www.airflowresearch.com/ . With the AFRs you could make 525 HP minimum with a good 347 engine at 7,000 RPM. In a 2,200 lb car you aren’t likely to want more on the street.

I know the Yates have a real “Wow” factor, but you would probably be biting off more than you bargained for trying to build the engine.

Kevin