351C 4V. What to do for torque?

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Don65Stang

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So how does one make a high reving 4-V 351c have a good amount of low end torque? I'm out of my element with the 351 cleves.

 


351C recently rebuilt



Holley 700cfm DP (model 4778-2 1433).



Edelbrock TORKER 351 intake.



4V dot heads.



Reed Cam. See cam card below.



Hooker Super Comp Headers.


 


IMG00263-20110221-1121.jpg


 


Apparently the previous owner wanted a rev happy, performance oriented engine and built it that way. Realistically I drive at less than 3500 rpm so I don't need a rev happy engine, I need one with some low end grunt; preferably lots of low end grunt. :D I'll be putting a Tremec 3550 5-spd behind it followed by 3.25 or 3.50 posi gears in the rear end.


 


::help:: What's do I do to get there? Sell the current engine and start over? Swap out the intake for a Blue Thunder dual plane? Swap out the cam? Different headers?
:huh:

 
IM RUNNING A BIG BLOCK, WELL MAYBE SOMEDAY NOW ITS ON THE ENGINE STAND. BUT I THOUGHT I FOUND A GOOD DEAL ON A 351C BUT IT FEEL THRU. ANYHOW I HAD STARTED RESEARCHING THEM AND FOUND THIS SITE, I HOPE YOU CAN FIND WHAT YOU NEED.

http://351cleveland.wetpaint.com/ GOOD HUNTING MY FRIEND
Yes, I think that is probably the best place to look... I've read the posts there but never registered. A little caution, you may wish to search the engine build posts because there is a ton of information that has been posted already... There are a couple guys on there that run Pantera's, and some engine builders like Mark McKeown and Tim Meyer.

I've got my Cleveland out and was going to rebuild for my pickup project. If you aren't set on the original heads, there are good aluminum heads available now, Trick Flow and CHI Aussie heads.

 
As you probably know, performance goals are primarily about 'trade offs." On the surface, your question seems relatively simple, BUT in reality it brings up other "issues."

Given the attributes of a particular cam, you can pretty well set up your rear end gears to take advantage of those attributes. There are mathematical formulas that will help you determine what rear end matches the power band of your camshaft. While that would probably be the easiest way to go, it has consequences in possibly higher gas usage:).

As tnfastbk said, stroking is also a viable approach but necessitates swapping out your rotating assembly which pretty much equates to a engine rebuild.

You could also change the camshaft to one with the attributes that matches your other components and your desired goals. Any of the major camshaft grinders can assist you with this.

Hope this helps.

BT

 
As you probably know, performance goals are primarily about 'trade offs." On the surface, your question seems relatively simple, BUT in reality it brings up other "issues."
Are we talking cars or women here? rofl

.



Given the attributes of a particular cam, you can pretty well set up your rear end gears to take advantage of those attributes. There are mathematical formulas that will help you determine what rear end matches the power band of your camshaft. While that would probably be the easiest way to go, it has consequences in possibly higher gas usage:).

As tnfastbk said, stroking is also a viable approach but necessitates swapping out your rotating assembly which pretty much equates to a engine rebuild.

You could also change the camshaft to one with the attributes that matches your other components and your desired goals. Any of the major camshaft grinders can assist you with this.
Good food for thought! I'm opting for the least expensive route so don't want to tear into a recently rebuilt engine, but a stroker would be awesome. I think I'll get the Tremec 3550 installed (once I find a set of pedals), drive it to see what it'll do and feels like, and then swap out the rear for a 9" posi...gears are yet to be determined - was thinking along the lines of a 3.25 to 3.50.

 
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If the cam was degreed in properly I don't see a problem with the cam. You could advance the cam 2-4 degrees and pick up low speed torque. The easiest, and probably the best thing to do is put a dual plane intake manifold on the engine. The Blue Thunder is a very good intake but more than you need and expensive. Find a 70 or early 71 stock 4V intake that is nearly square bore, as opposed to spread bore. You can make it truly square bore with a die grinder or sanding rolls. If you have room use a 1 inch 4 hole spacer under the carb. Set initial timing to 16 degrees BTDC, total advance at 36-38 degrees all in at 2800 RPM. The double pumper with 3.25-3.50 gears is questionable. Given the overdrive ratio in the Tremec you may want to consider 3.50 as the minimum gear ratio. This is not a computer controlled, VVT engine. If the rpm is too low at highway speeds you won't have the power or the mileage.

Good Luck,

Chuck

 
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