331 stroker in the UK

The single most important component of your engine build, from the standpoint of performance, is the selection of good-flowing cylinder heads. Well-designed heads won't need a cam with ridiculous lift, duration and ramp rates to make good power. Therefore, good cylinder heads will allow you to make good power while remaining "streetable."
 
Mark,
Thanks for the info. My last set of heads I ported myself (after much advice) and have been really pleased with them. If standard heads are opened up, ported and polished does it make much difference to go to better heads?
On Fordmuscle.com, some of their home ported heads actually flow better than expensive heads.
Would getting bigger valves in a standard head really make a significant difference?
Thanks.
 
Congratulations on having the guts to take a die grinder to a perfectly good pair of heads!
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It's a lot of fun, isn't it? It's hard to answer your question without a flow bench, but let me throw a couple numbers out there.

First, one of the US Mustang magazines did an article where they bolted AFR 185 cylinder heads onto a completely stock 5.0 and netted a 75 hp increase. Click herefor info on AFR 165 heads.

Second, I am not aware of anyone who has picked up more than 25 hp by porting stock heads. Not that it can't be done, but I've never seen it. I'd be interested to see the link to the fordmuscle.com page you referenced. Larger valves may help on the top end, but you would probably get better flow across the rpm range with a good (i.e., three- or five-angle) valve job.
 
What about Powerheads? They claim 38HP increase, although they don't say whether they mill the heads to increase compression along with the CNC porting...

Are we getting off topic here?
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I'm going to build myself a 331 stroker. Has anyone in the UK built one before? Can anyone give any advice? I've bought a SCAT 9000 stroker crank, but nothing else so far.
I'm going for H-beam rods for security but I don't expect silly BHP figures for the engine. It's got to have a smooth idle and lots of torque. I've built a standard 302 with a Performer plus cam and it idles superbly. Is that about as radical as I can go?
Thanks guys.
 
Mark,
This is the link to the fordmuscle article http://www.fordmuscle.com/archives/2000/07/homeporting/index.shtml
Unfortunatly it now seems you have to subscribe to see the whole article. If you know anyone who's a subscriber (I'm not) I'd recommend a look.
They flowed a pair of windsor heads, put in slightl larger valves and the flow was better than (from memory) all of the aftermarket heads they tested.
Mind you, I would have thought the aftermarket heads could have been ported evn more to up their numbers.
 
My engine is being built at the moment by Dave Milam of S D Racing Services.( TEL 01892 661245).

It is a 331 and we are expecting some very high H.P 450HP+. It is designed to rev to 8000RPM without any problems, but is bloody expensive.

Here is the basic build:
BOTTOM END:
Ford SVO block with girdle
Steel stroked crank.
H beam rods
JE Forged pistons and rings
True roller timing set
Vctr Junior Heads
ARP engine bolts
Solid lifter custom cam and lifters
TOP END:
Jenvey IDA throttle bodies
MOTEC M48

You mentioned you wanted lots of torque. Maybe a 347 would be better. For track use I wanted more bias with the HP, hence 331 ci was recommended by Dave Milam. I would suggest you give him a call.

Good Luck !

Regards,


J.P
 
That's not the article. Your article only shows how to port heads. The test article is called Head to Head. That article states that a set of 351W heads with larger valves and a port job flowed better than the run of the mill aftermarke (Performer)heads. They did not outflow the higher end heads like the Victor Jr., Twisted Wedge or even the Ford GT40X heads. The AFR heads, which seem to be the benchmark these days, were not tested. So, buying a set of 351W heads, porting and installing larger valves will increase your performance. But not as much as buying a set of AFR heads and just bolting them on. Oh, and then there's still the porting potential left in the AFR heads to consider.

David
 
David, You seem to be missing the point. What I'm asking is for the difference in financial terms. ie, is it worth spending $1,000 for (say) an extra 50 bhp when you can spend $100 and some time to gain an extra 40 bhp (please don't quote my figures, it's just an example!)
 
Hi,

I'm looking at the same issue now. I have stock 289 (1966) heads and thinking about porting them and fitting 1.84 intake and 1.55 exh. valves. I plan to fit an Edelbrock Performer RPM inlet manifold as this seems as good as any and very popular. With a 600cfm carb and 1.75 exhaust headers am I wasting my time i.e. will the heads still be the most restrictive link in the chain?
I really don't want to stump up £1,000 for a pair of Edelbrock performer RPM heads plus roller rockers etc etc.

Dave
 
AND..

can you fit a 351W in a GTD - seems the quickest/cheapest way to 400 bhp using a Ford engine??
 
I guess whether it's worth it is up to the individual. If you don't have the money to spend then the answer is probably no.

There is more than a horsepower gain when buying aftermarket heads. They usually come with modern valve componenets (stainless undercut valves, springs, keepers, valve guides, pushrod guides), and they are setup for stud mounted rockers. There is also the weight advantage with aluminum heads.

You originaly stated that you wanted to make good power and retain a smooth idle. Since that rules out a lumpy cam I believe that the next logical option is aftermarket heads. I don't think it makes sense to put heads that flowed poorly on a 289 or 302 on a 331 stroker.

[ February 24, 2003: Message edited by: David Sanchez ]

[ February 24, 2003: Message edited by: David Sanchez ]
 
Take these numbers with a grain of salt - we've had discussions about Dyno2000 before, but I plugged some numbers into Dyno2000 and here's what I got:

331 CI w/stock heads, 9.0:1 compression yielded 302 HP @ 5000 RPM

331 CI w/"Ported/Large Valve" heads, keeping CR @ 9.0:1 yielded 386 HP @ 6000 RPM

331 CI w/Edelbrock Performer heads, keeping CR @ 9.0:1 yielded 407 HP @ 6000 RPM

Cam, induction, exhaust, and CR remained unchanged for the three examples.
 
That's about what I would expect according to the article. The results showed that well ported heads with large valves flowed comparable to the low end of the aftermarket heads.
 
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