|01-14-2016 02:19 PM|
|01-14-2016 07:49 AM|
I would think that companies like Edelbrock would pay a royalty or at least get permission from GM or whoever to make parts based on their design.
But the total knockoff industry has no R & D or engineering back up on anything they produce. Do they do testing, run FEA on anything they make? I tend to doubt it.
I make lots of knockoff parts myself, I'm sure many of us do to suit our needs. But we don't try to market them.
|01-13-2016 10:50 AM|
i are really smart too i believe. Some say different however. Whew, now that we've got that over with... There are guys who go buy a well-engineered, well-made and pricey item, take it to China or India and say "make this"...whether the manufacturer knows what they were making or not, a shipping container of copies comes back and is on the market here looking just like the original. It's a good way to make a buck, I know or know-of a couple people who do just this. In many cases it's necessary and fair, such as for reproducing a no-longer-available part...in others it's just a blatant rip-off of the original mfr. effort. Hopefully for the sake of the end user they at-least get the quality right, but in any event I try to not support people doing the latter.
That said, the worst-made (design, casting and machining) part I've ever bought was from right here in the USA from a company calling themselves "the greatest name in racing". It was a long time ago but I never forgot dropping an intake manifold that cost me a week's wages into the scrap barrel when I was finally fed up with it. So it's not like you can just rely on anything...or not...based on where it came from.
|01-13-2016 08:21 AM|
Speed Master sells a lot of Pro Comp parts, maybe they own them? I see lots of their rockers sold by KMJ, total knock-offs of any rocker under the sun. Both Speedway, Summit and I'm sure Jegs and others sell as well.
I looked at some other aluminum heads (Flotek) sold by Speedway and was steered away from them by my engine builder. Cast in China, machined & assembled here.
I wound up with Dart aluminum heads and intake, Lunati cam, lifters and roller rockers. Push rods are from Comp Cams (bought locally).
My thoughts, build it once and build it right. I tried to use US made components everywhere in the build.
|01-09-2016 01:00 PM|
1st gen procomps
I know this thread is really old but i want to add to this procomp debate with my actual history. first a little on me. I am a process engineer. i started out at the bottom as a machinist running a drill press or handscrew. i was smart and soon was running CNC lathe and mills. because i am fairly smart i kept right on going and now i am figuring out how to process medical instrument and implate parts thru a machine shop, send out to passivation, plating, silk screening what ever is needed. i know parts and machining. casting everything to make a chunk of metal in to a beautiful instrument that will possibly save a life or make it better. NUF said about me.
I'm just building a SBC 350 (355) for my 65 malibu SS. I like to play and do everything so my car is set up for street, strip, autocross, whatever trouble i can get my self in to. I first bought a set 1st gen 190cc, straight plug, 64cc chambers, 2.02/1.6 heads, complete off ebay. the casting core shift was horrible on the intake runner of 1 head. bad enough to where the center port dividers only overlapped the head by .03 and i didnt think it would seal and sent them back. aside from the casting core shift the machining looked superb. all threads and milling look great. nice finish everywhere. the intake ports were very small on these 190cc heads. smaller than my "461" camel back heads. because of the core shift and me sending them back, the seller let me exchange/upgrade to the 210cc intake, angle plug, 64cc chamber, 2.02/1.6 heads, set up for roller cam (i did not know these werre raised runner intake ports). these heads were much better. again the machining looked excellent, all threads were nice, all milled surfaces looked great. there are very large casting ribs in the intake port in two places. 1 is by the push rod and the other is closer to the bowl end around a head bolt between the Siamesed runners. the distance cross the opening by the push rod was smaller than my 461 heads because of the casting bulge. i figured "aluminum casting" and that these were supposed to be ported, so i did just that. i also checked the valve seat to guide runnout and all the seats were within .002 except for 3 seats were .003, .004, .006. i feel this is pretty good considering 16 seats. i have had fresh heads out of the box on "American" made heads that had seats up to .015 out of whack so this wasn't to bad right out of the box. I like to see less than .002 so i corrected the three seats. all the exhaust seats were within .002 right from the start. also, the intake port is a raised port on these heads so it doesn't work with stock gaskets. you need the larger and thicker felpro 1266 gasket. a 1206 will not work it is too thin. I gasket matched a Vic Jr intake to the raised port head. an RPM air gap didnt have enough meat to do this, at least the one i had looked at. after porting the intake runner out as far as i felt safe without going to thin and breaking thru i still had some small casting humps but it is way more open and the raised intake runner is supposed to help make more power so i dealt with the extra porting of the intake. i installed the heads on the motor using the procomp parts as i was short on money and time and figured i would upgrade the parts after the summer of driving. the engine ran like a raped ape. i have a howards oem style roller cam p/n 180265-10. paired with 1.6 rockers it is .565 lift int/ .581 ex. final lift. so far the heads are kicking as. i raced a buddy with a 409 sbc with Dart heads and he dynoed at 498 hp 502 tq and its in a 74 buick apollo with the same 3.73 rear gears i have in my malibu. we raced and we were dead even so im assuming im making close to his power with a 355 cid engine. not bad at all.
after this summer ended i pulled the heads off and inspected parts. all the ends of the exhaust valves were beat to ****, looked like they have been actuated by a chisel & hammer. some of the valve tips had little chunks of metal chipped out of the edges and the end surface looked horrible in general. one intake valve also looked like this. I was also running some really crappy KMJ stainless steel full roller rocker arms. DO NOT BUY THOSE THEY ARE JUNK. the roller tip is not perpendicular with the rocker trunion so the roller tip doesn't contact the valve tip squarely.
Back to the heads, the seats and castings still look great after beating this motor about 4000 miles this summer. i am now installing manley valves, crower springs, comp cams ultra pro magnum full roller steel rocker arms.
i could have bought the heads as bare castings and looking at this with hind sight, thats what i should have done. i think the bare castings were around 350.00, add the 300.00 for new manley valves and crower springs, & stem seals i would have been right around the 650.00 i paid for the complete heads with crappy parts. i know procomp is now speedway and i heard they have improved quite a bit. so i would tell you i am very happy with the heads but not the parts installed in the heads. the new speedway heads might be better. i could have saved a lot of money if i would have bought bare heads. with that being said, even after upgrading the valves, valve springs, valve guide seals, plus add gaskets i am still LESS than the cost of a pair of complete "American" made heads. total cost is sitting close to $1000.00 after all the upgraded parts are added in. So Mrperformanceparts is pretty much right on the money. you need to ask, or build it your self so you know what parts are in your heads. then you will have no worries.
|07-04-2014 12:15 PM|
|Sundance7055||I have the same heads on my 383...the problem with these heads are there is too much meat inside the chambers witch block the flow...check it out you'll see...I saw a video on you tube that dealt with this problem|
|04-22-2013 05:40 PM|
|04-22-2013 03:32 PM|
is it me r does the rocker arms not look right.
Yes i know this is over a month old
|03-01-2013 08:26 PM|
I got some cnc AVG/PC 351C A3 port heads for $1900 complete, really nice castings, really happy with them, looking to buy another set right now.
|11-16-2012 03:17 PM|
|496CHEVY3100||me 2 cents I purchaced a set of procomp oval port 300cc aluminum heads pro comp layered gaskets and proconp studs for aluminum headsfor a total of $1150.00 including tax from ASA in COLUMBUS GA add said completly assembeled opened package today to puy on my BBC engine they are NOT together have to put on guide plates and studs problem is bolts for studs are7/16, holes in heads 4 are 7/16 4 are 1/2 holes 1 head came with helicoil but they dont fit the holes 2 guide plates do not align with pushrods the set at approx 30 degrees so i am going to have to remove heads redrill tap and helicoil both heads so rocker studs will fit i will loose layered head gaskets 70.00 plus labor sealer and antiseize trial fit intake after problem with heads you guessed it, intake does not fit some of bolt holes are off 1/2 of the hole this is a factory GM tripower intake so i cant enlongate holes with runing value of intake approx $1200 just incase anyone cares I AM NOT HAPPY, Dont wast your money|
|10-15-2012 06:26 PM|
|Jim Rockford||Why was it back when we made everything here and bought the things WE made a man could have a decent paying job and things where affordable... **** went to hell in a hand basket when we started importing all this crap and sending jobs overseas.|
|10-15-2012 05:32 PM|
Based on the valve issue, sound like the previous owner lied to you and they had a clean up and new valves put in. There are several dealers on ebay selling the heads with their own valves and springs. No telling what they do in assembling them. Hard to say it's Procomp's fault.
Could also be a machine shop drumming up business..."yep, they're all bad"
My heads worked perfect. The new owner has had them on a year and loves them. My Airwolf heads use a Procomp core and are flat out ******.
|10-15-2012 03:31 PM|
Pro comp heads
I have the new revised 210/ 64 pro comp heads on my sbc 383. Motor is in a 1967
firebird. 3000lbs and I am running 10.90 at 122mph and 6.95 in the 1/8 th @ 99mph
I bought the heads bare and put in my own hardware. Running a .600 solid roller by lunati. Have a ton of passes on them and no problems. Until you buy a set of the new ones dont knock them...
|06-19-2012 09:03 PM|
So now I have input on Pro Comp aluminum heads, and it ain't good.
Last fall I got a smokin deal on a pair I found on the local Craigslist. $500 for the pair and a set of ARP head bolts tossed in too! Brand new, but had been installed on a SBC, but never started up.
Well I was looking for a pair of old "fuelie" heads, but what the heck, these were too good to pass up. Famous last words! I picked them up and during the off season I installed them on the 327 in my Austin gasser. The heads were angle plug, which created some clearance issues, but I got around that. Installed a new set of roller tip rockers, and a new cam while it was all apart.
A couple weeks ago I started noticing one cylinder was not firing well at idle. Pulled the valve covers to find one rocker had a bad roller! It also ate up the valve stem a little, so pulled the head and took it to the local machine shop to have it looked at.
Machinist told me the next day that all the valves were sloppy in their guides! Said it appeared someone bored the guides without honing them to fit each valve correctly. Pulled the 2nd head and he confirmed it also was assembled in the same sloppy manner and all valves guides were sloppy.
Wasn't too excited aout having to replace all the guides, especially when I found out they're all oversized OD also! The new guides would have to either come from Pro Comp, or one of their distributors like Skip White in Tn.
At that point I decided to cut my losses. He had a pair of old 2.02 camel hump cast iron Chevy heads with all new SS valves, hardened seats, new guides and seals, and chambers CC'd. I gave him the crap Pro Comp heads and $150. and walked out the door happy.
In the end it was a cheap lesson, and one I wont forget. I'll never buy Pro Comp again, but if anyone considers them be sure to get bare heads and have your local machine shop assemble and fit them. Don't let the idiots at Pro Comp toss them together!
|04-24-2012 08:06 PM|
|onlyfnway||Well we finally got some track time in on the 509ci BBC with the procomp heads. took a little work to get it dialed in but it went 5.84 on motor and 5.31 on a small kit.|
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