351C stroker build

[Muck]

This is my first time on this forum so my apologies for any noobie mistakes in advance. I am currently restoring my 1971 Mach1 351c 4v with c-6 that I have owned for the last 23yrs. I had the motor built in 1989 0.30 over with go fast goodies of the day. Intake, headers, ss valves and lifters, 2800 stall shift kit, 3.90 gears in the limited slip 9" rear. It runs just fine but before it gets put back in, I'm seriously contemplating putting a stroker kit in it. Question #1 is 393 vs 408, and Question #2 is stock heads vs aluminum. I plan to have fun driving it on the weekends maybe take it to the track once, but not a regular racer. All help and input is appreciated.

 

[[email protected]]

Hello,

quencher heads (4v) with huge runners and small chambers are better for top end horse power. So designed for high rpm, not really street. You can read lots of info here about 2v heads and Aussie so called 3v heads. Seems like the more open chamber and smaller runners are better for lower rpm performance. They have the added benefit of dropping your CR to a reasonable number for pump gas.

Assuming you want street power cubes do it

just my 2 cents

 

[hyena429]

Open chambered 4v heads are good too....They dont ping as bad on now days fuel....You can get pistons to bump them up just as far as closed chamber heads.......Open chamber heads with the right pop up piston set will pull just as much compression and breath better...and flow just as high horse power as closed...apples and oranges.

As for aluminum...They are lighter...But alot of test flows show the cast irons will flow more than your block can handle...lol...All counts on how light you want it....But the power and reliablity of cast iron heads are hard to beat...Reason why you dont see many 4v mustangs with diffrent heads...Unlike chevy's 350...lol

Sounds like a monster set up....As for the stroker part..roy im sure can anser part of that.....I never needed to put one in yet in my stang...lol

 

[TommyK]

Welcome.

Can you tell us a little more about your combo? What cam, intake, carb, ignition?

Are you looking to achieve a specific horsepower goal or ET?

If it runs good might be a couple of tweaks to your current combo will get you where you want to be. A well sorted 351C with iron 4V heads can be a hand full.

 

[Jeff73Mach1]

I'm in a similar position of trying to design my next engine build.

These are a few of the general conclusions I have reached

408's apparently are easier to get neutral balanced than 393's

Stroker engines, especially the thin wall clevelands do generate increased piston thrust against the cylinder wall, so for the sake of argument a stroker should not last as long as a stock stroke engine.

overbore should be kept to the absolute bare minimum that will clean up the block in order to maintain as much block integrity as possible.

The only advantage to aluminum heads is the weight reduction. The disadvantage to the 3V heads is the propriatary intake manifolds.

I beam rods are adequate for all but the most extreme builds.

You have to be careful as to whether the crank is cleveland or cleveland style-all are not equal.

your camshaft should be a custom grind from someone that knows all about your engine set up. Lots of lift, lots of duration. and it should be broken in on a cam break in fixture if at all possible.

Open chamber heads are fine and work about as well as closed chamber heads in most respects. If using closed chamber heads, the quench height (distance between top of piston at top of stroke and head is critical.

Wolverine should not paint your parts.

 

[Tnfastbk]

I agree with a few of the statements so far but........................

1. I will take a set of cc 4v heads any day over oc 4v or 2v heads.

2. A Roller cam will not need to be broken in on a cam break in fixture, even though I'm not sure what that is.

3. The AFD heads have a preferred intake, but you can use any intake you like with a little thought. But you CAN NOT use ram air with the high port heads. http://www.airflowdynamics.com.au/site_flash/products/cleveland_heads.htm

4. 408 vs 393 is like small block to big block, personal preference. More 408's built than 393's.

5. Just do your homework and buy quality stuff and you will be fine. If you want to talk to the man who is the man on the 408's contact Mark @ http://mmeracing.com/

6. You can check out my garage for some on my motor

7. Absolutely do not let Wolverine paint your parts

 

[marks73]

FORD Closed Chamber 71 heads. Negative on the stroking, Get what you have yet to unleash out of what you have. Only way to go! And if Wolverine volunteers to paint for you....RUN!!!!!

 

[Muck]

I do not have a specific hp/tq or et in mind, just want more than what I already have and don't want to pull the motor for another 20+ years. That being said, I would guess that I'm currently around 325hp and expect to get to 450hp and similar tq with the 408 and Al heads. I spoke briefly yesterday with Mark at mmeracing and he suggested Trickflow heads and the 408 over the 393. It is my understanding that the stock heads are "ok" but will not provide streetable torque. The aftermarket Al heads will provide a better tq curve at lower rpm. Also the Al heads will help with weight (not my biggest concern, probably best that I lose weight vs the car lol), better cooling and better with CR. The stock will come on at 5k+ and I don't plan on driving it in the "red" that much. Initially I was interested in the Al 3v heads but they seem to be a bit cost prohibitive and more for race applications. Any thoughts on the Comp mutha thumper cams? I do not have a ram air set up currently and I assume that I will not be able to use one anyway with the raised plane intakes that run best with the Al heads due to the raised carb height. I currently have a Ford dist that is converted to pointless, msd 6a and Accel supercoil. I will obviously have to swap out the dist.

 

[Tnfastbk]

When you get a plan in your head call comp cams and have them custom grind one for you. They will make you whatever you need for around the same money as off the shelf. Just remember to match everything, IE cam, springs lifters,carb, intake, etc...... Change one thing and it will effect another and so on. You dont want to buy parts twice I would assume. The strokers are a little different animal with specific needs.

 

[c9zx]

::welcome:: From what you've described you want I'd say 408 rather than 393 or 377. I built a 408 for my street 72 Mach 1 that will never see more than 6500 RPM. I had no tolerance, manufacturing, or machine work problems with the SCAT cast crank and I beam rods. I used the Mahle "Power-Pak" dished pistons and ring package made for the 4 inch stroke (9.6:1 static CR). They are almost pieces of art and reasonably priced. I used CC 4V factory heads that I did some relatively minor (but time consuming) clean up work in the runners, bowls, and chambers, using a friend's flow bench to check progress, Ferrea 6000 + .100 SS valves, and adjustable valve train. Intake is Blue Thunder dual plane, carb is Holley HP 750. On the dyno, with standard correction, the engine made 450 lb/ft of torque from 3000-6000 RPM, max of 496 @ 4900 RPM. Max HP was 529 @ 6400. I used a pretty aggressive (12 in. hg. at 1000 RPM in gear) solid cam but you could have a good custom hydraulic ground and still make good power. How aggressive of a cam profile depends on what you want and are willing to trade off. Stay away from tight (104-108) lobe separation cams in Factory 4V headed Clevelands. DO use split lift/duration cams in Factory 4Vs just don't go too far with the duration numbers. Use should consider a larger oil pan and the priority oiling modifications to improve longevity. FIND A MACHINE SHOP THAT BUILDS CLEVELANDS. If they don't have a deck plate for a cleveland, go elsewhere. Have fun with the build! Chuck