More 351 W questions

[diiulio]

I have read through many of the previous posts, but there isn't one that really explains the stroker benefits and downfalls. My plan is similar to many others as I have read on this board, 400 hp and 400 ft/lb torque are my goals. My plan is to have a toploader, probably wide ratio bolted to the 351W.

So, I have concluded a few options:
1. 393 Stroker w/ scat crank, AFR heads, performer RPM intake, 700-750cfm Holley and cam to match all.

2. AFR heads, Performer RPM intake, 600-700 cfm Holley, and cam to match all.

3. Using a longer rod, i.e. Buick 231 V6 rods to be a 397 ci, but utilizing the stock crank and options of #2 with maybe a larger carb.

My concerns.
1. Not too street friendly, high heat, gas consumption (not really a big issue).

2. Not going to meet the 400 hp and 400 ft/lb marks.

3. A lot of machine work and definitely need to be done by a professional and not in my garage.

So, basically I like the #1 option, but would like to hear opinions of experienced people/professionals.

Thanks
Jason

[Roscoe]

Stroker Tips & Tech Advice


5 Ways of Building Torque

Cubic Inches
Stroking creates more displacement, and displacement means power.

Compression
More displacement makes it easier to produce high compression without massive domed pistons.

Lever Action
A longer stroke is a longer lever acting on the crankshaft, thus providing more torque.

Pressure Power
Longer stroke creates faster piston speeds, which means that the piston can create a more accurate pressure drop to fill the cylinder more thoroughly at low rpm for torque.

Rod Angularity
Increasing stroke without increasing rod length increases torque because the piston-speed dynamics and rod ratio conspire to create more cylinder pressure at maximum rod angularity. When this occurs, the rod has the greatest mechanical advantage over the crank.

[Mr.Fixit]

Strokers are great for these reasons: more CID, more leverage at the crank makes more torque, less weight than going to a big block, did I mention TORQUE. Contrary to popular belief, you can spin a stroker to high RPMS, and your valvetrain will still be the limiting factor, if you have a good crank, H-beam rods, lightweight forged pistons and ARP main studs. Long rods are great, but then you need custom pistons. Don't forget the other little details like a small diameter cam so it doesn't get hit. You can easily make 400/400 in a 351 without stroking it, but if you had gone stroker, you would have another 50-60 just because of the cubic inches. I suggest having it done by somebody that has experience in building max-effort stroker windsors. I wouldn't run a dual plane intake on a cobra, they are light enought to not need the low rpm help, run a vic jr. just my $.02

[Ron61]

Jason,

Several of the guy's around here have used an Edilbrock kit with their stock 351Ws and have had great success. They don't have any dyno figures but two of them told me that they had talked to Edilbrock people and they told them that with the performer kit I think it is, they should be getting around 400-430 horse and around 400 pound torque. I have driven one of the cars and it runs great. He is running a T-5 World Class transmission with a .68 split and 3:27 gears and it will almost keep up with my stroker in the first 2 gears. And it sure is easier to maintain than mine. So you might give Edilbrock a call and talk to them as one option.


Ron

[diiulio]

Alright, stroking sounds like a great option.

What are the negative/downsides of stroking?

Why a push for a professional build?

[Mr.Fixit]

Originally posted by diiulio


Alright, stroking sounds like a great option.

What are the negative/downsides of stroking?

Why a push for a professional build?

Do you have a barber, a dentist, a lawyer, a doctor?

When doing engine development on stroker winsors, the shop I worked for went through several different length strokes, four types of heads, dozens of camshafts, different rod lengths, intakes, carb setups, etc. The result was nearly 100 more HP from essentially the "same" type of motor. We learned what worked well, what just plain worked, and what doesn't work. The parts are going to cost roughly the same, the machining will be the same, the extra $1000 to have a professional make the component selection, put it all together and warantee it, that's the best money you can spend on the motor. Rebuilding a stock motor to the same configuration is something I would recomend, developing a working combination where everything is changed, I hope you have time and money for the engine development project.

CC member "66 Snake" has this

stroker dyno results
I'm running a 418 ci. w/ AFR 225 heads and 10.5 to 1.
dynoed 606 hp @ 6200 and 572 ft.lb. @5100
I run this motor on pump gas only and no pings.

amatuer engine builders don't find those results, that is the result of a continued development program.

[auto10x]

Again, did anyone mention TORQUE !!! Don´t forget, horsepower numbers/effects are only meaningful if you spin the engine at high RPMs (5-6000). Around town you will likely have more fun with high torque than you will high horsepower.
auto10x
Bill

[diiulio]

Yes, this will mainly for be street. I doubt I will get above 5500 rpm.

The thing is, if I buy a stroker kit it comes with pistons, rods, crank, etc. There is no trial and error with parts except for heads and cam. That is what I am wondering, I am not building an engine to race, but to drive the snot out of. Of course I want the most out of it, but not at a cost of thousands extra for some extra horses. So, then as I have read, AFR makes great heads and with over 350 ci I may want to step up to the 225 instead of 185's. Then, just figure out the cam.

This isn't rocket science, is it?