351w Buildup

wickedmach1 · #1 (**permalink**) 03-11-2004, 08:00 PM

I am rebuilding a '69 351w engine and need some help. I want to make around 425 - 450 HP. What parts would you guys use? Should I do the roller cam conversion or stay with the mech flat tappet? I have power disc brakes and need to maintain a safe vacuum. A rough idle is okay as long as it is drivable. The car will be used on the street as weekend fun. Please include the specs of the cam so that I can do some research on which company to use. Your help is appreciated.

Bruce Edwards · #2 (**permalink**) 03-11-2004, 08:19 PM

Edelbrock has a RPM package with heads, cam and intake that is good for 400+hp with just a bit more help. 10.5 pistons and a few other little things and it will give you a strong runner with little upkeep. However the 69 block is not as tall as latter blocks and you may have to mill the piston tops to fit. It's not good when they come out of the top of the bore.
We top it off with a 750 Holley and it is good to go.

Tony Radford · #3 (**permalink**) 03-12-2004, 04:16 AM

You gotta stroke it.

Bruce Edwards · #4 (**permalink**) 03-12-2004, 06:00 AM

Tony I see a lot of post about stroked engines on this site and I do not get it. Why spend the money to stroke a 351 to 427? Why not just get a 390, 410, 428 instead? I can see stroking an engine for a stump puller that needs the extra bottom end power to get the thing moving but most Cobra's are only around 2,400 lbs. It is not like you can not spin the tires. A stroked engine will not rev as fast or as high as a more square engine, bore and stroke close to the same, due to the added dwell time of the piston at the bottom and top of the stroke. That plus the added weight of the parts flying around inside the block also has an effect of slowing the rev ability. A heavy part is harder to get to change direction than a lighter one.
So again I do not understand why this would be a good idea in such a lite car. The 351 will push 400+ hp with out all of the work of stroking and the expense that is involved in doing so. Plus it will rev faster and higher so it will go of the line faster and have a higher top end. So again I do not get it what am I missing?

Mike Simard · #5 (**permalink**) 03-12-2004, 06:43 AM

Bruce, if your goal is a powerful, fast car and you're not goverened by displacement rules, the most important thing to do is to have the most displacement a given engine can reliably handle without getting into awkward rod configurations. The idea of a smaller displacement engine being faster because it can rev more freely has no merit. Yes, more rotating mass robs power and limits max rpm's but the increase in power from displacement will be far greater than that loss as well as the lower max speed of the motor.
The first thing they teach in 'how to make a car fast 101' should be to make the motor as big as possible and the car as light as possible.
As far as why not a 390 or 428 instead of a stroked Windsor? That might be cool, If I had one it would actually have around 500 cu. in. but I want to road race my car and overall weight is important too. For me, an Aluminum windsor is nice because it will be 400 lbs and the Dart block allows a 4.125 bore, a 4.0 crank fits and it will have 427 cu. in. with an acceptable 1.55 rod ratio.

Tony Radford · #6 (**permalink**) 03-12-2004, 06:43 AM

Bruce, I understand your rationalization. Almost all of the Cobra guys here in Atlanta are running Windsor strokers in their cars. I put 7,500 miles on my car with a 410 HP stock stroke Windsor and really enjoyed it. Last fall, I had the engine replaced with a 427 Windsor stroker. Let me tell you, there is absolutely no comparison. And you can't compare a stroked Windsor to a BB. The characteristics are quite different. My stroker has an optimum shift point of 6,200 RPMs where my other motor died at 5,000. I'm running lightweight pistons, H-beam rods and an aluminum flywheel. My engine revs exponentially faster than my stock stroke motor. Remember, stroking isn't about additional displacement. It's about moving that connecting rod further away from the crank centerline. It's torque that give you that "jet-fighter" sensation. Ask anyone who's running a stroker that has experience with a non-stroker and see how many say they wish they hadn't changed. If I were to race my old configuration with my new one, the old Tony would be slaughtered! That should be enough to tell you that the fun factor in considerably higher.

auto10x · #7 (**permalink**) 03-12-2004, 10:50 AM

Can't make accurate comparisons with regard to engine acceleration when you have changed to lite weight pistons and an AL flywheel. Apples and oranges.
auto10x
Bill

MrMagoo · #8 (**permalink**) 03-12-2004, 11:29 AM

Isnt weight the big reason why people go with strokers as opposed to FE's?

Bruce Edwards · #9 (**permalink**) 03-12-2004, 11:45 AM

MRMaggo, With all of the aluminum parts you can get for the FE engines that is not much of a factor any more.
Mike, I understand all about weight vs HP. You can not tell me that for all the cash you have tied upin your Dart you could not get a FE that would do the same thing.
Tony, If your old motor went away at 5,000 rpm and the new motor will spin higher that is a fault of what you had in the stock engine. I fyou had a smaller cam or other issue and now you have made up for that with the new engine then I would say you could have seen the same result from putting those parts in your stock engine.
I have built everything from VW to Corvairs to 426 Hemi's and 427 Fords. I understand all about blowers maybe inches yes. With that in mind I still have a problem with a high toque engine in such a lite car. The ones I build for Cobras have a rpm top of 7,000 or better, will rip the rubber off the back end for as long as you want tp keep your foot in it and will run for 100,000 plus miles with not much more than a tune up and oil changes. No fancy parts just good old HD parts that will not break and a balanced system.
I have one customer with a 351W I built in his Classic Cobra that will go 70+ with the AC on turning 1200 rpm in 5th so I do not see how touqe is much of an issue. That car if you drop it to third and step on it will rip your head off.
Touqe gets you moving HP gives you the top end speed.

FattyBri · #10 (**permalink**) 03-12-2004, 11:48 AM

I have a 357ci Windsor that made 394rwhp/415rwtq through a C4 automatic trans. Hoping for more through a tremmec 5-spd. Heads are gasket/port matched Edelbrock Vic. Jrs. Intake is gasket/port matched Edelbrock Vic. Jr. Holley 700 double pumper. Comp cams XE282HR. 10.5-1 compression.

I was looking to build a 408 stroker, but got a great deal on this motor. If you have to rebuild the motor anyway, you might as well build a stroker.