3.2 Head Fact or Fiction?

[DCPorscheFreak]

I have an '86 3.2 Carrera with 137k miles on it.

Lots of receipts over the years but nothing comprehensive, only spot fixes (replaced #3 valves but no guides??!!). The car runs very well considering everything, but I'm starting to plan for a rebuild.

I spoke with Bob Farmer of Farmer's Automotive in Indiana last fall while I was still looking (a car he'd worked on was for sale). He shared a LOT of info, most intriguing was how poorly (his words) 3.2 heads breathe.

He claims that he's welded up 3.2 heads and then re-ported them to achieve much better flow, more power, and cooler running temps all with the stock intake FI and exhaust system. Using his own grind of cam, he's achieved 250 HP and 230 lb/ft of torque w/ stock chip and exhaust as measured on his bench dyno. Farmers Automotive. When my builder contacted him though, he quoted huge prices ($6,000 for heads & cams?!) which almost doubles my rebuild cost. I rebuilt a 2.4E to 2.7 RS specs+ that cost $12k 6 years ago, so I've got an idea of what this 3.2 should cost, and $ is definitely "an object".

As a Washington DC resident, if I want to drive my 911 everyday, so I have to have it inspected regularly and maintain all emissions, etc., regardless of it's age. It's fine now in stock form (K&N cone, Vertex chip, stock exhaust & cat), but if I'm going to spend all that $ for a rebuild, I would like to tweak as much as possible. E.g. CE euro pistons w/ higher compression?

Questions:
1. What head mods can/should be done to improve breathing for a street motor, if any?
2. What would such mods cost per head?
3. What kind of power and torque improvements have any of you realized with these mods?

Anyone seen/driven a Farmer engine? Is any of this for real?

I'm asking both as a reality check and to see what other alternatives may be out there.

Thanks,
John

[toddu]

No disrespect to Mr. Farmer, but give Mike Bruns (JB Racing) or Steve Weiner (Rennsport Systems) a call. Both have extensive experience bench flowing all different kinds of heads and can give you more information than you can imagine.

Todd

[jmh61]

That's the first I've heard of 3.2 heads being a limiting factor. I've been told that they easily support over 300hp. You might try talking with Bill DiCondini:

BILL DICONDINA
XTREME CYLINDER HEADS
(772)-286-1660
bill@xtremecylinderheads.com
Xtreme Cylinder Heads And Castings

All he does is cylinder heads. He recently redid my heads with all new valves and seats, and some tweaking for less than half what you were quoted.

[AlfonsoR]

If I were going to get head work done, I too would put Xtreme at the top.

Just my personal opinion, I am not an engine builder an am also planning my first rebuild... If you are going to go all out, including PMO carbs or ITB injection, then the stock heads might be a limiting factor. If however, you are sticking to your stock induction system, then I would think that the heads in stock form are sufficient. Would it help to optimize flow a bit to get better swirl or more tumble for improved efficiency? Probably, but I don't think the gain would be substantial, and not worthwhile ($$$), when using a stock induction system.

[Steve@Rennsport]

Bone-stock 3.2 heads support up to 325 BHP without any modifications or enhancements.

Beyond that, I would talk to Bill about getting his heads.

[Matt Monson]

My stock '86 3.2l with 105k on it, never been rebuilt, and has nothing more than a Wong chip for mods made 227whp on a local dyno. Assuming 10% driveline loss, that is pretty similar to Farmer's engine dyno bench numbers on his reworked heads. I mean no offense to Farmer but my personal experience suggests that my stock engine already performs in the realm of his worked one...

[DCPorscheFreak]

Thanks all; your collective replies give me a good sense of what to do.

As a corollary question, what about a Euro-spec compression motor vs. the lower compression US?

I have 93 octane gas here in abundance on the east coast and since I'm planning on JE pistons, can tailor the CR to an extent to suit.

Best,
John