To stroke or not to stroke, that is the question

[Jon Briggs]

OK, I'm getting to the point of needing to make some decisions with the engine I am stripping.

My current thinking is for a 331 stroker kit with forged pistons but cast rods and crank, a 282 duration hydraulic roller cam, AFR 185 heads 68cc, and 1.6 roller rockers. My plan is to have throttle body fuel injection that looks very similar to the Webber set up and run coil packs with an Emerald ECU. As for a transaxle I am thinking of a Renault UN1 or Audi. I would like about 375-400hp from the engine, which in these cars should make life interesting.

However, I know just enough to make myself look stupid. So any advice on the above set up would be greatly appreciated.

 

[Peter Delaney]

Jonny, I have just about the same setup that you are proposing, but I think my AFR's are 165cc.

Could not be happier - it ticks over like a sewing machine at idle, but scares me when I put the boot in !

Whilst I have not had mine on the dyno, other guys with the same setup are getting up to 435hp (reliable & streetable).

Its a nice motor - you might not get the bragging rights that come with 500hp, but you are driving past as those guys are guiding their cars onto a tilt-tray !!

Kind Regards,

Peter D.

 

[Terry Oxandale]

For decades I either ran a 302 or 289, but never delved into the stroker kits until the last engine build, which was a 351W stroked to 383 (shortest stroker with longest rod). AFR 205s, a nice solid roller. Turned out to be the best running motor I'd ever driven. Typical shift points were 7K (girdle, H-beams, and forged pistons). The cam I used was a "spare" from a Jegs Torque Master competition. I believe it made over 500 lb/ft from 2800-5800, but it pulled hard all the way to 7. With the girdle and the 9 quart oil pan add-ons that I didn't have on the 302/289, it added 60 lbs to the total weight of the car, but made the car into what I was always looking for, but never quite had with the 289/302.

Unfortunately, it went with the sold car. If I don't go with the LSxx series motors (couple of inches shorter) on this next project, and stick with the Ford, there is no question that I'm going to repeat the build, even with the complete 289 sitting in the corner.

 

[Mike Pass]

I would suggest that your spec is pretty good . I would have the block line honed and then decked as these old blocks can be 15thou out on the head faces. Then get it accurately rebored and honed using a deck plate which simulates the effect of the cylinder torque and ensures that the bores are round when everything is torqued up. I would also suggest using a steel stroker kit which are cheap and strong and having it internally balanced. The standard method is to have an external balance and this puts an out of balance loading on the mains which can knock out the centre main and wear the outer mains at an angle due to the crank flexing if regular high revs are used. If you get the right crank they can be balanced without the use of heavy slugs and the balance can be achieved by removing metal instead. Don't go mad on the cam or it will be a pain in traffic.
Martin Gough had one done recently and using Edelbrock performer RPM heads, Air gap manifold and a 650cfm Holley and a flat tappet road cam on a 347 ci Eagle stroker kit with H section rods, gave 420 hp and 430 ft lbs (374ft lbs from 3,000rpm) on the dyno and was as smooth as silk. Talk to Kenny Coleman at Engine Data Analysis. He can do anthing on V8s and you can watch your engine on the dyno and get a proper corrected printout. He does a superb job of block prep and has special jigs to ensure a super mains - deck - bore alignment.
Engine Data Analysis "Specialist Engine Building & Tuning"
Tel: 01977 516622
Cheers
Mike

 

[Jon Briggs]

Guys,
Thanks very much for the replies. It looks like the spec is fairly set now, I might go with a 58cc head chamber to up the compression to just over 9.5:1 and may be a 347 stroker instead of 331.

Anyone got any advice about engine builders around the Midlands area, I am based near Leicester.

Mike thanks for the heads up on Engine Data Analysis, I will give them a call.

 

[Simon]

Mike Huddart is THE MAN!!!
Just call him up and have a chat, you'll be sold!
Don't know where you are in relation to him, but trust me, he's worth the journey (and reasonable)

Simon

 

[Jon Briggs]

Thanks simon,
Gave Mike a call yesterday and am going to try to catch up with him at Stoneleigh. Wife permiting!

 

[Stew Stau]

For the same power, the 302 will be kinder to your transaxle (important if not modified on a UN1) than the 331 but be less streetworthy.

Just a thought. Either one can be tuned to enough power to blow up the transaxle you're thinking of.