Topic: 351 clevland rebuild

[dstang351]

hello everyone this is my first time writing on this, but i have read over a few subjects and learned alot. but now that i am starting to rebuild my car for the second time ( i didn't change my oil after i took off my head and i think anit-freez got in my bloc, i was young and learing well that was 4 yrs ago now i want to do it right)i have a few questions. i have a 351 C .030 with a stock crank and 2V heads that have alittle work, and a weiland single plane manifold. i had a 520 lift compcam in but now sure if i should go with that or not? that is kinda my question what is a good carb cam combo for the 351? or were could i find out, i would like over 400hp and no that the 351 can do that with little to no prob (well at least that is what i i've read on this). thanks alot

[Soaring]

There are a lot of different aftermarket things you can bolt on that will make that "C" a screamer, but if money is a problem here is what I suggest.
Call Crane or Comp Cams and have them grind this hydraulic camshaft for you......or get an F246 cam. 

.524" intake lift / .554" exhaust lift,,,,you could go up to a 600 lift cam if you want it loapy.
224 degrees intake / 236 degrees exhaust duration at .050" lift
110 degree lobe sep angle with the intake ground on a 106 centerline

Add 4V heads, (AFR?) You already have a very good intake if it is a 4V intake. Add a decent 750 cfm carb (Holley?). 1 7/8" headers and you're in business. Just keep the C6  (although a built C4 won't rob you of as much horsepower) and add the 3.89 gears. You'll have fun.  This is just my 2 cents.  Others may have a better idea. 

[Jeff73Mach1]

Your cam is too mild for 400 horsepower.  I have a Comp Cams 282S with 570 lift and even it is probably a bit mild for 400 horsepower with my 4v Closed chamber heads, but any more cam and you start to run into vacuum problems and decreased low end torque.

A G tech estimates and ET's suggest my engine is putting out 325 at the rear wheels, but only a dyno will say for sure.  Competition Cams says my combo should be getting around 500 flywheel horsepower.  I think their numbers are high and the G tech are likely a little low, but really, numbers don't mean too much.

My car will do 0-60 in 5.6 consistently with 3.50 gears and a stick shift even though it weighs 3,900 lbs with a driver and gas in it.  With 4,11 gears and an automatic with the right stall speed converter and it would be 5.0 flat I suspect.

I would not waste the time and money on 2V heads.  If you need 4V open chamber heads, I have a spare set I would sell reasonable, but they will need to be gone through as they still have stock valves and you should go to modern stainless 1 piece valves as the factory valves are a known weak point on these engines.

Conside oil restrictors or an external line from the galley to the rear sending unit to cure some oiling problems known to exist in the clevelands.

One thing I will preach is get a Cleveland specific thermostat, not what the parts monkeys want to give you

http://www.banzairunnerpantera.com/updates_thermostat.htm

I went with a 180 and it keeps my engine running very cool.

Make sure and match intake to head type.  a 4v intake will run on a 2v engine, but it will perform poorly and vice versa.

Hooker makes a header for 180 with 1 7/8 pipes and a 3" collector.   It is there Comp series, not the super comp.

What is your plan for the ignition system and air cleaner set up?

[Tim175]

That cam will not get you the 400 horsepower you are looking for. Clevos can make tons of power but they cost a lot sadly. I just finished building mine and just for the machine work and the parts cost 5k but i went all out. You could obviously save a lot of money but it would still be quite expensive. What are you looking to spend? A few things you could do to make more power though would be: bigger cam (obviously), bigger carb, headers, 4v heads etc. Again the biggest thing is how much are you looking to spend then go from there.

[Jeff73Mach1]

I looked at the Aussie heads and they sound like a good option if you want a torquey street engine designed to stay under 5500 to 6000 rpm-accordingly a matching cam profile that makes power in that range is necessary.  They are essentially 2V heads with a closed or quench chamber and will increase compression.

With 3.73 gears and a 2500 RPM stall speed converter and a 600CFM carb I would expect this combination to be fun to drive on the street, good off the line but it would not be a 400 horsepower engine.  On the other hand it might well put out 400 foot pounds of torque which is more of what you feel than horsepower and it will certainly start producing torque a good 1500 rpm lower than a 4V equipped engine.

Personally I chose the 4V closed chamber heads and built my engine to try and take advantage of the high rpm airflow knowing that it would mean a weaker low rpm range.

The 4V Open Chamber heads I have would be good for a street engine and have the larger valve size.  The Open chamber heads will be leaving your compression pretty much unchanged.  You would need to spend $300.00-500.00 to put in new stainless valves, guides and seals.  Springs need to match your cam selection.

These heads are complete and were running fine, but I would rebuild them with 1 piece valves.  I'd sell them as cores for $300.00 plus shipping, but I don't think that is the best route for you.

There are aluminum 3V heads that combine the 4V exhaust port with the 2V intake port that are probably a great compromise.  The cheap ones are just that though and would need some port and polish work by someone that knows what they are doing.

Your block needs to be inspected as a Cleveland block may not take another overbore.

If I were in your position I might consider buying a used running engine, or swapping to a Windsor or a 460 (which would add a transmission exchange to the process)

I researched what I was going to do and got results that I am happy with.  I think you could get there a number of different ways though.