a question about heads..

thebigbread · Post by **thebigbread** » Sat Sep 15, 2007 8:42 pm

Ive been wondering this for a while...

If all A-series engines (4age, 7afe, 3ac, ect) use the same bolt pattern for their heads, does this mean i could possibly swap a twin-cam head on my 3ac?

of course, id need a new timing belt, but it could mean a considerable gain in HP.

Post by **Petros** » Mon Sep 17, 2007 8:37 pm

I think someone has done this, I remember reading about it on the list some time ago. Several issues however, you have to make sure the valves clear the top of the bore since the bore is smaller diameter. It likely would have low compression because it would have a larger clearance volumn (you could put in flat top pistons available from Sealed Power, and mill the head to off-set this). You would have to workout the correct valve timing. Plus the same issues with the distributor coming off the back of the head, and making a custom exhaust header, induction system, etc. If I was going to do that much work I would just go for the full 4afe/age conversion. It would also end up being quite expensive I think.

thebigbread · Post by **thebigbread** » Mon Sep 17, 2007 8:54 pm

actually im already saving up for a 4age swap, i was just curious.

well, in other words its too much trouble for too little gain, right?

shogun · Post by **shogun** » Mon Sep 17, 2007 10:31 pm

im going back to boost, at the end of the year, right now collecting parts to get the job done right

ill tell you how it did work out