I need some input, guys. So, I have the opportunity to get a SMOKIN' deal on a set of aluminum heads. They're Trick Flow knock-off's, but, good castings. Here's the run-down: -60cc chambers -2.02/1.60 valves -180cc+ intake runners (just an estimate, need to verify) -All new springs, valves, seals, retainers, studs, etc. Knife-edged and blended. -$700 out-the-door from my machine shop. (They've been sittin' there for 5 years, brand-new and forgotten, and my machinist just agreed to sell them to me today ) Here's the problem: I just installed domed pistons and a Total Seal ring set a while back. My cam's a flat-tappet and has .512 lift, 280* duration, 110* LSA. I calculated my static compression at around 10.28:1 and my dynamic compression around 8.48:1. Motor's a 302 (+.040), stock rotating assembly and I'd use 1.6 rocker arms. So, here are my questions: 1.) Possible PTV clearance issues? (just looking for opinions, here) 2.) Will I be able to run 91 octane pump gas? (timing and carb dialed in) I need to get some feedback so I can decide whether or not to pull the trigger on these heads. They're for a daily-driver. I know I'll have to clay them up and everything, but, I'm just looking for general opinions. You guys think there's a possibility they'll work, or, am I living in a pipe dream and treading the line? Eric
As far as the ptv clearance you may have problems but since it is a 60cc head and the lift is not that big you will probably be okay but no guarantee until you put them on and check the clearance. You could always use a thicker head gasket but then you will drop the cr down. I have flat tops and have a 60 cc head and piston is .005 out of the hole I believe with .560 lift You will be able to run it with 91 pump gas no problem as long as timing is set right, I have a bit more compression and have never had a problem with good pump gas. Hopefully you can get the seller to match the springs to your cam. What knock offs are they
aluminum heads...are a little more forgiving on timing than iron heads so the 91 shouldn't be a problem...JMO
I wish I could tell you what they were. They have, absolutely, no markings on them. The cylinder head guy (Derrick) does nothing but head work at the shop (and has been for 25 years) and got really fired up when talking about them. He went on about the fineness of the casting porosity and the bowl/runner profiles. He doesn't get excited about much, so, that got me very interested. Said he didn't know who made them, but, an excellent job was done. He told me that Trick Flow's were the closest things he could compare them to. My pistons are 0.008 below deck with a -2.6cc head volume. I would feel a lot better if I could lower the compression just a hair, though, and I would feel great if I could get a better idea of PTV clearance. Eric
Not knowing what the springs were set up for would scare me more than anything else. I would sure try to identify them. Any markings on them at all ?
Have him pull a spring and measure spring pressure at seat pressure and over the nose heights. Find out what the installed height was. That should tell you if they will work with your cam. 60cc is pretty forgiving on compression and a little 302 doesn't build a lot of compression easily due to the short stroke. What valves are in it? Stainless? What series? Street, race, undercut...? Are the valve retainers steel, moly, aluminum, titanium or what? What angle keepers? All that said, if they have been abandoned for 5 years, they are making a ton of money off you for a set of no name heads. Look around, you can buy several brands of heads for that kind of money these days. Offer them $500 cash, in hundred dollar bills laid on the counter, if they check out good for spring pressures, etc. You might be surprised. It's almost pure profit for them if they were abandoned heads. SPark
I'll bet they are Pro Comps, Chinese knock off of the E'brocks... Trick Flow have rotated valves that are moved closer to their respective ports, easy to spot the valves aren't exactly in line... Do they have a the exhaust gas crossover to supply heat to intake??? Pro Comps I have don't...
No matter how good they look, have them flowed tested on a flow bench. That is where subtle and not so subtle differences between the original and the copy begin to show up. There is a copy of a CHI Cleveland head sold on Ebay that won't even come close to the flow figures generated by the original. You might end up with something that produces no more power than one of the better iron OEM heads.
Okay, so I just got back from the machine shop about 20 minutes ago. 1.) These heads have no hardware. They're bare. I just ordered all new springs, retainers, locks, and valves today. It'll all be here tomorrow. We ordered the new stuff from Comp and matched it all to my cam. 2.) The heads have offset valves, just like Trick Flows. Derrick (dude mentioned above) said he pulled up a spec sheet on Trick Flow heads and all the angles/measurements of these knock-offs matched up, almost, perfectly. He said someone tried very hard to imitate the Trick Flow castings, and succeeded to a great extent. 3.) Double-checked today and still couldn't find any markings, PN's, or casting numbers. Nothing. Nada. Must've spent 15-20 minutes poring over every square inch. Hell, I even looked inside the runners. 4.) Price got lowered to $600 out-the-door cuz I said I'd do my own set-up for the valves and stuff. 5.) Learned, hands-on, how to "balance" valve springs from Derrick. Very useful information. PTV clearance is my biggest concern, right now. Everything else looks like it'll work ok. They're gonna cc the intake and exhaust runners and deck the heads for me, tomorrow, before I come in to pay. They've, already, got a 5-angle job, blended/smoothed bowls, and new valve guides. I dunno... I think I'm getting a good deal for a decent set of aluminum castings, fully machined, and all new hardware. It was either these for $600, or, the E-street heads from Edelbrock for $1k. Sure, they're crap compared to the AFR 165's I used to have, but, "beggars can't be choosers." Right now, I just gotta get the car on the road (with some minor "go-fast" exceptions ). So, what say you, men, to me having PTV issues? Opinions? Eric
As long as the cam does`nt have over 300 degrees of advertised duration,I doubt seriously there will be any ptv problems.You can really over cam a stock 302 & get away w/ it.
Agreed, same is stated by Trick Flow... I ran flat tops without valve reliefs using the TF Stage-1 cam, no issues at all...
What in the world in "balancing" valve springs? Do you mean deburring the ends and "blueprinting" them? Never heard of a balanced valve spring. SPark
I can only imagine he's referring to "balancing installed heights" to get preload to the same on all.