I am building a sbc 327 that i aquired with a project i bought. It has a set of aluminum gen 1 trick flow twisted wedge heads with it...I have sent the block away and it cam back .030 over and the crank (forged small journal) was turned .010/.010.. I will be using an edelbrock performer intake and have installed a mild cam 284int/284exh, .458 lift on a 110 lsa. I am going to run 1.6 lifters so that will put my cam at about a .498 lift.. This is just a street motor going in a 66 c10 with a 3.73 rear end and a 700r4 trans once i get it completed. I am using speedpro H660cp30 pistons that end up being .025 below the deck. I am planning to use the felpro 1094 shim gasket to put my quench at .040. I began working on the heads and did not like how the mating surface was from years of wear so i had them cleaned up and they ended up having to take .015 off the heads. This made me start thinking...How could i ever tell if these heads were ever surfaced before i got them etc...they are supposed to be 64cc heads....so i got out a sheet of Plexiglas, Vaseline to seal it around the chamber and a small "syringe" to measure the cc's...With my rudimentary test, i cam up with 59/60cc's...so it looks to me like these have been cleaned up before as well...so...now my questions...lol... I ran the numbers on a compression calculator online and come up with 10.38:1 compression, when i use the new lower chamber volume... Will i be able to run this motor on pump gas like that? I was thinking i heard you can usually run 93 octane up to 10.5:1...I have heard it has a lot to do with your cam etc...Can someone give me some thoughts on this and my build....I am at the point of installing the heads so i have not installed head gaskets or intake or anything like that...all i have done is check my ptv and retainer to seal clearances and have stopped there for now until I know for sure i am good to proceed... Thanks in advance! Chad
I never seen a set of twisted wedge heads for a small block Chevy.... How about posting some pictures of one.... Especially the combustion chambers... Thanks a bunch!!!!
you should be fine....or not...depending on where you live. Here at 4200 ft, we have no problem. At sea level in cool air, maybe it'll ping, but probably not. Since they are aluminum heads with small chambers and you have good quench, it will probably be ok.
Im in illinois (600ft above sea level)...was hoping with the good quench and aluminum, i should be good...Tks..
Just remember that the valve reliefs in the pistons dont line up with the valves in the twisted heads. I think its the intakes if I remember correctly. This limits the amount of lift you can run with out custom valve reliefs. Make sure to measure valve to piston clearance!!!!
Hell it is just a small journal small block Hell it is just a small journal small block Chevy V8 and nothing special but you have to make sure the heads work with pistons you are running. Meaning quite simply you have to go back to the manufactures of the heads and tell them that I have these Pn______ heads and am using these ________ pistons. how do I make it work. If you didn't sit down and do your homework before you laid out the coin for the combined batch of parts you now have I have very little sympathy as it is alway research first, spend second if you want it to work without asking how the hell do I make this work now. chev c
We did a customer build with these heads back when they first came out and Twisted had a maximum lift number with stock pistons, It was a fairly low number but I dont remember it exactly. We just cut some new reliefs because we exceeded the max number. I dont have my flow bench records anymore but I think the intakes flew pretty well right out of the box.
Seems to be the exhaust valves that are "twisted"; rotated and angled relative to the piston, if that makes any sense? I almost bought a pair from Summit a few years back, but could't wrap my head around the valve positioning. If a couple of pics had been posted, I'd have ordered them. I would't worry too much about the C.R. you're coming up with; I'd be more worried about the hyperutectic pistons. I am Butch/56sedandelivery.
That CR wouldn’t worry me at all, like most things timing is everything! just make sure you double check PTV clearance you are lower on lift but most twisted-wedge applications REQUIRE matching pistons also I’m sure you are aware but those take a “special” intake rocker and you’ll have different length pushrods for int and exh. A little extra time now will save you from a really nice looking and expensive boat anchor Sent from my iPhone using The H.A.M.B. mobile app
Trick flow stared out doing big block the small block ford heads, real popular with 5.0 crowd, before moving into chevy heads. The valves likely wont line up or work with your existing valve reliefs, as pointed out. So after you flycut the pistons, your compression concerns should be gone.
Clay up the tops of the pistons and check your valve clearance, this link is pretty good. http://blog.jepistons.com/how-to-check-piston-to-valve-clearance-with-clay
Just got off the phone with Trick Flow...They actually laughed when i told them all the talk about these heads online...his exact words were there is so much miss information on these heads online its crazy..lol Per Trick Flow and the paper work with the heads...Maximum Cam Specs with flat top pistons and 1.250 springs: 238* duration @ /050, 106 lsa, with a .512 lift...I fall under all of these values ( 218 @ .050 .458lift 110lsa) and yes i did check on all of this before i purchased anything and yes i have clayed the head and have PLENTY of clearance. I also asked about the "special" intake rockers...he said "what?"...there are not special rockers required...They do recommend a Good rocker and not a rocker that was make to fit several different motors. They recommend Crane Golds and that is what i am planning to run, and you have to be meticulous on setting up your push rod lengths.
Like my engine builder told me, the cam doesn't care whose rocker arms you use. You did right by talking to Trick Flow. I had talked with Dart and Lunati before I shelled any $$ out with my heads or cam. I used the rockers that Lunati recommended, of course it was their product.
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