well i was kinda wondering if i should deck the head at all, seeing as there might hardly be any room, and even less room for error. The only reason i was going to deck it was to get the c/r a lil higher, and I will if i can. However i wont be replacing the '72 pistons. I might be waay off here: I think the clearance for a 72 block/stock pistons with a 430 heads and a felpro head gasket (.040"?) is .100"? if i put big valves in there that decreases....020"? deck the head .020"...that leaves me with .060"clearance? If thats right, that be ok wouldnt it? Is that correct?
I'm afraid it's quite a bit more complicated than that. When you change the cam's duration, even leaving everything else the same can still mean trouble. For instance, during the exhaust stroke, the piston is actually chasing the exhaust valve upwards while the valve is closing. Leave the valve open longer, especially with more peak lift, and the piston may actually catch up and tag the valve..."tag", you're "it" and have broken parts. Also keep in mind there are no "standard" measurements you can rely on, as all machine work at Buick had its tolerances, and you never can tell what may already have done to an engine in the past. Have you ever done a valve-to-piston clearance check? We were talking about it on this thread not long ago: http://www.v8buick.com/showthread.php?t=138531 Devon
I think you will regret running that cam.. to much cam and not enough supporting parts are a common mistake that result in a Buick running poorly. I'd bet money that a smaller cam with your combination would make more torque and hp and still be street friendly
No more truthful words have ever been spoken. A badder sounding cam does not always mean a faster car just like adding a bigger cam does not always mean your car will be quicker especially on the street. A guy named Dennis Manner once pointed this out to me. He knows a thing or two about Buick engines.
Without compression, head work, gears and a good exhaust set up, the cam won't be much fun. But again, once the above things are dialed in, a modern grind with more lift will work better. But, you already have the cam...o No: Devon
it will eventually be getting posi with better gears aswell as an intake/headers and the heads are gasked matched & midly ported ..and yes, its on street tires for now I figured i could get some flimsy springs are push the valves down with a dail indicator to chck p/v clearance.
with a 72 block and 430 heads you will be lucky if you have 8.5 compression. you will have little to no bottom end torque and your heads and intake wont flow well enough to make any power at 5000 rpm and above especially with stock manifolds. you were better off when you decided to go with the 113 cam.
its stock 8.5:1...with 430 heads and a little milling it should be 9:1! As I said before, im planning on getting an edelbrock intake man. Btw, its got lotsa TQ
it was rated by the factory at 8.5 but in reality was closer to 8.0 compression the 70 455 was rated at 10.0 but was closer to the 9's and shaving the heads does very little to increase compression on a Buick
No offense, but what we're trying to say is that you shouldn't be surprised when the bottom end torque pretty much disappears. It's the same with my combo. I run a bit more cam than the 107, but even with extensive head work and custom headers/exhaust, the car would be a turd if not for the switch pitch trans and the higher compression. The loss of the bottom end torque can be somewhat overcome with a loose converter, but with low compression and little head work, it's going to run out of steam above 5000 rpm as well. Devon
lets calculate your compression ratio 71-74 engines used a piston with a 36 cc dish. 67-69 combustion chambers, 68 cc stock deck height is usually .050 head gasket thickness .040 head Gasket bore is 4.380 inputing this info to my compression ratio program gives a compression ratio of 8.4
so would a TA310 or a 288-94h 288-98h 290-94h GS113 GS113a or GS118 be a better option? Or would half of those be not such a good idea cuz of the lower c/r since some are recommended for 9.5:1 btw, does anyone have a link for the poston cams specs???
update: well guys i completely stripped the engine over the last couple days, and am buying 10:1 valve-notched pistons on top of the other things i've already listed. Also boring the block .030" over and buying all new bearings/seals/gaskets. Getting a machinist to polish the crank and size up the con-rods aswell. The 107 cam should really work nicely with a proper stall converter now.
are they pistons TA's conical dish? they would go nice with that cam see if your machineist has a torque plate for boring/honing the 455 if not you might be able to rent one from TA
im actually trying to figure out exactly what pistons im getting...havent yet...any more suggestions? I will definitely need them to be valve-slotted
I've read the thread. Sounds like you want to build the engine around this used 107 cam because it has a bad sounding idle and use it mainly on the street. The cam has a no low end gas guzzling carb confusing 41* overlap and the stock heads will choke it on the top end. Now you are looking into buying pistons because of it. ou: . Guys with alot of experience answered your question about this cam. You will get into spending alot of $ to get it to run properly for your intended use. I'll be running the GS113 cam a 72 455 stock bottom end (block oiling mods., oil pump mods., crank grinded for proper clearances etc..) with 67 heads and expect to crank out some 12's. A bigger cam is not always better. Usually worse on the street. Everything works as a combination. If you go with aftermarket pistons the rotating assembly must be balanced. Hyp. and any forged are not the same weight as stock. No matter what the brand. Ray
If i remember correctly the 107 cam was a cheater type cam meant for someone who didn't feel like taking there motor apart.you could just put it in a stock 10-1 motor no port work w open headers, switch pitch,slicks and run 12's all day.I also remember it as a kenne-bell cam (the window rattler).I saw a woman at the gs nats a few years back running very low 12's w it in a street car and it sounded nasty,needed a vacume canister for the brakes.Cool sh!t but it's nostalgic outdated junk and i wouldn't use it anymore.Do what rob says and get a recomendation from ta
