Pros and cons stroker kit for 302?

[Geert-Jan]

I decided on going to rebuild my 302 engine, to make it my winter project.
Since I am going to do this, I might consider a stroker kit, but I don't know about the pros and cons.

My 302 is mated with a UN1 with LSD. It has 48IDA Webbers.
It now has 366hp @ 5748rpm and 476Nm @ 4687rpm.

I use the car mainly for trackdays, but also want it to be good for road use.

 

[Mike Pass]

Message sent.
Cheers
Mike

 

[JP Verweij]

What are your plans? rebuild it yourself or get somebody rebuild your engine.
You might consider one of Real Steel 327 crate engines http://www.realsteel.co.uk/section2a.pdf.
I have the gold card, but they probably sell you one anyway to get that discount.

 

[Geert-Jan]

No, I want to stick with my 302 and just rebuild/refresh it.

 

[Bill Kearley]

Unlike me. Stay with common sense. A conservative 302 is good for reliable 350 HP, lots for a 40. Look at Ford racing catalog for proven parts and specs.

 

[JP Verweij]

Why take a 366 bhp 302 apart for a fresh-up ??

 

[Dwight]

stroke it to 347
should have 450 plus hp and torque
Pick the correct cam for the type of driving you will be doing with the webbers. Maybe the cam you have will work just fine.

 

[Ian Anderson]

stroke it to 347
should have 450 plus hp and torque
Pick the correct cam for the type of driving you will be doing with the webbers. Maybe the cam you have will work just fine.

That sounds great but you are then into the breaking gearbox category with a UN1
They can handle about 400 he tq before having problems

Ian

 

[Dwight]

You can break anything if you try hard.

If you are doing a lot of burn outs in the parking lot, yes. If you are using sticky tires and shifting fast, yes, tranny is not going to last a long time.
If you are road racing, slow shifts, then the UN1 might last a long time.
I've know guys drag racing with T-5 for years before they broke. T-5 in a road racing Mustang never broke. 3550 in a Cobra road racing for 8 years with a 427.
Point is, how you drive sometime is of more value than the part.

 

[Geert-Jan]

Hmmmmmm, the more info, the more questions the more I hesitate.....

 

[JP Verweij]

Well here's some more info you won't like to know. Piston choice, Cast, Hypereutectic and Forged.

Forged & Hypereutectic needs more piston to bore clearance. As described in the manufactorers instructions. Its not what Ford says, its what the piston maker says.
These specifications are always instructed for front engined cars and have differend specs for road car, SUV, Pickup truck heavy towing (more clearance) and fuel like propane (even more piston to bore clearance).
But in a rear engined GT40 they might even need some more clearance.
That also count's for ring gap. This is where the GT40 specialist engine builder comes into play.
A stroker kit is not drop & forget. If you just drop it, you can just forget all about it and it will fail.

And with 366bhp on tap you have nothing to complain.
About your carbs, Ill have the synchronise gauges and less than two hours away. but you knew that allready.
You'r engine is been dyno'd allready so jetting should be oke.

 

[Neil]

Do not even consider using cast pistons in anything but a junker. Hypereutectic pistons are good for a hot street car but forged pistons are the only choice for a high performance engine.

Why not add a stroker kit when rebuilding your 302? You wind up with more torque so you don't need to wind up the RPM. Less wear on the engine- especially the valve gear. The larger displacement is without weight penalty, too. Why sacrifice cubic inches?

 

[Randy V]

Guess what engines use cast Hypereutectic pistons!
Chevrolet ZL1, ZR1/Z06 and every LS series performance engine.
Look back at the Dodge Viper, Ford Coyote and many others...
Hypereutectic pistons allow for far tighter bore clearances which are more supportive of low tension rings. More HP and greater longevity of the reciprocating assemblies..
Today’s pistons cannot be compared to what we knew 20 years ago.
—
The 331 I built for my GT dynoed at 415 hp, 430 tq and is very docile without a ton of valve overlap.. I would build another one of those over a stock block 347 as you don’t need to notch piston bores and the rod ratios are better (in my opinion)...

 

[Simon]

I had a ford 302 in my first Cobra. I fitted a 331 stroker kit and had the whole reciprocating assy balanced. A slightly hotter street cam was fitted with mildly ported heads. It was a peach of an engine. Idled quietly and very smoothly but with a ton of torque. Plenty more powerful engines out there but this was an absolute joy to drive. To much power is not always a good thing.
Just my 2p worth.
Simon

 

[Howard Jones]

366Hp is just right for a combo street/track car. That is also just about the limit for a standard UN-1. If it was my money and I wanted to drop lap times I would get a second set of wheels and mount slicks on them . I think you will also need to add about 150 lbs per corner on the springs from a nice soft street setting.

R6-7 Hoosiers are good for about 5-8 seconds a lap over middle of the road street tires on a 2- 21/2 min lap. On most tracks 100hp won't get you that without better brakes (and tires) and an increase in corner speed (tires again).

Keep the motor, get the tires, brakes and suspension setup.

 

[Neil]

Guess what engines use cast Hypereutectic pistons!
Chevrolet ZL1, ZR1/Z06 and every LS series performance engine.
Look back at the Dodge Viper, Ford Coyote and many others...
Hypereutectic pistons allow for far tighter bore clearances which are more supportive of low tension rings. More HP and greater longevity of the reciprocating assemblies..
Today’s pistons cannot be compared to what we knew 20 years ago.
—
The 331 I built for my GT dynoed at 415 hp, 430 tq and is very docile without a ton of valve overlap.. I would build another one of those over a stock block 347 as you don’t need to notch piston bores and the rod ratios are better (in my opinion)...

Yes, Randy, that is my point- those are all street engines. Hypereutectic pistons are excellent for those applications. When those engines are fitted to a race car, however, they are replaced with good forged pistons.

 

[Dwight]

I think I paid $400 more for an all forged Eagle rotating assembly for my 347. I know I don't need it but it piece of mind thing.

 

[Jac Mac]

No, I want to stick with my 302 and just rebuild/refresh it.

You answered your own question, forget all the stroker stuff & concentrate on doing a proper rebuild of what you have and optimise the ~302" combination.

 

[Randy V]

Yes, Randy, that is my point- those are all street engines. Hypereutectic pistons are excellent for those applications. When those engines are fitted to a race car, however, they are replaced with good forged pistons.

Check them out Neil... Many of those cars with those engines are racing in competition and winning! These pistons are not as heavy as they once were and work quite well. I will say that there are some cheaper brands that I would not use though. Keith Black pistons are in that class. I’ve built them with both forged and Hypereutectic and it is easier to get custom pistons in Forged..

 

[JP Verweij]

How about de-stroke it to period correct 289??
These days the 289's are pretty fast. They have way more bhp then they had back in the days.
The teams & drivers that still racing the GT40's & Cobra's (same engine) still prove that.