I will have a few questions about this motor but i will ask them as i get to them or think or them. but first, what would be the best cam to put in it and whats the most lift that will fit with out any further mods. what can i do about all the 351c over heating problems i hear about?
I believe the cam can go to .500" lift with the correct springs, and still keep the fulcrum rockers. There are 2 types of fulcrums... Aluminum and iron. Make sure to use the iron type. The aluminum ones are known to gall up with any sort of performance springs or cam. That is a very bad thing. Clevelands are known to overheat under the follow circumstances: 1: Bore more than .030" over. If the bore is sonic checked for thickness, you might find a block with enough meat to bore further without issue. 2: Under the thermostat, in the block, there is a steel restrictor ring. If that has been removed, the engine WILL overheat. 3: Running without a thermostat. Any temp stat you want, as long as there is one in place, you will be fine. Not a big thing, but closed chamber heads run cooler and can run higher compression than open chamber heads. 9:1 is considered high for open chambers and can even require 93 octane in performance use. Closed chambers ran 11:1 from the factory and can stay there if you are certain to run 93 octane. Therefore, if you are going to be forced to run 93, why not do it with 11:1 compression vs 9:1?
Dave covered the cam specs, but I'll add that the last Cleveland I sold had a Comp Cams 280H cam in it and stock rockers, it had no issues with it and it had a .533 lift. The stock 351CJ springs(Ford also used these springs on the GT 390 and 428CJ too) will handle this lift level with no other mods. I've run a 390 and a 427 with the same CJ springs and two different cams with .515 and .526 lifts. I have a set of iron fulcrums I'll toss in the deal as well. The 78-82 351M/400 heads had better valves and the iron fulcrums, the fulcrums from the 370 and 460 truck motors had the same rockers and iron fulcrums as well. Quench heads may be out of his reach, he has two choices there, either 70-71 4 bbl heads or a set of "Aussie" 2 bbl heads. I'm giving him two sets of open chambered 2 bbl heads in the deal. If he can get a set of Aussie heads, he'll have plenty of extra valves to choose from if he needs to replace some.
My opinion,,,,ALWAYS go to aftermarket valves! 3 piece Ford valves can trash a engine fast! Tim Meyers Inc should have a good supply of Aussie heads
Talking about the shape of the combustion chamber. The U.S. 2 bbl heads and the post 71 4 bbl heads have large, round open chambers. This was a good way to improve emissions, but played hell with controlling the pinging, in other words, they're prone to detonation and need a higher octane fuel with the same compression ratio vs a "closed" or "quench" chambered head. Quench happens when the piston nears top dead center and the fuel/air mixture is squeezed between the bottom of the head, outside of the chamber and the piston top. This extinguishes any spontaneous explosions from the fuel reaching the flash point. Only the flame started by the spark plug in the chamber is the one you want. The pinging sound you hear in detonation is actually several flame fronts colliding with each other, this damages pistons and valves. The early U.S. 4 bbl heads and the Australian 2 bbl heads have the quench chambers.
baddad457, Excellent explanation. I now have a much better understanding of the difference between open and closed chambers--------in a language I understand. Thank you.
Summit Racing IMO... No sales plug. Just who I deal with personally. They are not a sponsor or member here, so I don't neccesarily endorse them beyond being my preference. How was that for diplomatic?
Good cleveland stuff comes available on ebay and on the cleveland form classifieds and swap meets, you just have to start being able to spot it. It usually isn't right out front like the more common 302 and windsor stuff. You can order most aftermarket stuff for them right from any major supplier, some parts are limited in choices, but overall not so bad.
If you do, do business with Summit Racing, just remember that they have far more stuff stocked, than they advertise. It helps to have the part number for what you want to shop with them. The Tech line might help, but I've never had the opportunity to find out, I hunt down the part number of what I want and order online. There's a good Cleveland forum on www.network54.com/119419/ lots of stuff in the classifieds there too.
summit is were ive been looking and pricing stuff, how does the 4bbl dubble pumper work and whats yalls take on it?
Unless you're going to full time drag race it, leave the double pumpers alone. A tuned vacuum secondary carb will be more than enough, and still get the best mileage.
