More HI-PO Cams???

There are people that know better than me....

The cams in an engine, are not REALLY made for the specific engine, you could put alot of cams in our engine and it would still run fine. Or at least run, the number of the cams are far more telling than the model of engine stamped on the box. Of course some are made with a type of engine in mind, and some are made with a specific engine appliction in mind for high-performance. These guy seem to have a much better grasp on the numbers than I could fake.

The internal differences between our engines are the cranks, rods, pistons, and a few other odds and ends. If the specs on the cams, duration, lift, and those numbers, are good to make power in a supercharged 4-banger, with a 6,500 rpm limit, they'll make power in our engine...

I don't think the bore is different, just the stroke. I believe they it is 86mm for both the 2.0 and 2.2.

IIRC the cams in the GM Performance catalog have been around for about 3 years now. They are actually CROWER units and the PN# you have listed is a "set" that includes Intake cam PN# 86958636 and Exhaust cam # 86958637. They were the original "race grind" ECOTEC cams pioneered by the late great John Lingenfelter and Bothwell Motorsports joint venture that did the original engine destructive testing and mods for the GM ECOTEC Racing program. They were also reportedly the cams used in the Saturn ION Bonneville record breaker in 2003.
BUT
They aren't setup for the LSJ IIRC. The regular L61 ECOTECs have an extension on the end of the intake cam to drive the P/S pump (blocked off on the ION) But on the LSJ BOTH cams have this extension - it drives the cam sensor unit off the end of the exhaust cam. Best bet would be to buy TWO Intake cam blanks and have them ground to your own specifications. I've provided a copy of the COMPcams as a guidline- but you might want to back down on the duration somewhat to reduce overlap on a "boosted" cam set.The part number for the INTAKE blank is PN#88958611 and you will need 2

You're correct, many of the GM Performace Parts web-sites have the specs for these cams screwed up. Here are the detailed specs as printed in the ECOTEC Engine Handbook. You might be able to get more info directly from Crower (who also makes the billet race crankshaft found in the GM performance parts catalog I might ad)

Regards
WopOnTour

I can understand it, alot of people have bolted things on before, and if it dosen't fit, you can usually see it right away. Other people that might not know a ton about cams and valvetrains, might be concerned that the two engines could require cams that look completely opposite to each other, or something. If it's the first 'performance-styled' car that someone has owned, I can see being very careful over something unfamiliar like cam shafts, it SOUNDS like you're really getting into the engine internals.

Everyone just has to understand, cams are cams. There might be some that are better or worse than others, but a cam built for either of the two engines will fit. It's the numbers and specs on the cam that determine the performance, or lack of performance, that the cams will provide. If you put them next to each other, you might be able to see a difference, MIGHT, but either of them will drop right into the car. The ones advertised as a 'blower-grind' are the ones that are designed to go with our engines, because they are a supercharged Ecotec. If you put a blower in the 2.2, then you could use the same cam as we would. On the flip side, if you removed our blower, and made it N/A, you would use one of the 3 that are being called 'the ones for the 2.2'. The only reason they're for the 2.2 (it would be more accurate to call them: Cams for non-forced induction Ecotecs), is because it's not blown or a turbo.

Sp00ner said:

I can understand it, alot of people have bolted things on before, and if it dosen't fit, you can usually see it right away. Other people that might not know a ton about cams and valvetrains, might be concerned that the two engines could require cams that look completely opposite to each other, or something. If it's the first 'performance-styled' car that someone has owned, I can see being very careful over something unfamiliar like cam shafts, it SOUNDS like you're really getting into the engine internals.

Everyone just has to understand, cams are cams. There might be some that are better or worse than others, but a cam built for either of the two engines will fit. It's the numbers and specs on the cam that determine the performance, or lack of performance, that the cams will provide. If you put them next to each other, you might be able to see a difference, MIGHT, but either of them will drop right into the car. The ones advertised as a 'blower-grind' are the ones that are designed to go with our engines, because they are a supercharged Ecotec. If you put a blower in the 2.2, then you could use the same cam as we would. On the flip side, if you removed our blower, and made it N/A, you would use one of the 3 that are being called 'the ones for the 2.2'. The only reason they're for the 2.2 (it would be more accurate to call them: Cams for non-forced induction Ecotecs), is because it's not blown or a turbo.

Click to expand...

I think you hit the nail on my frustration head The questions and statements about cams that will or wont fit a 2.0 if a 2.2L is mentioned. Shit, my '02 Sunfire GT would run just fine with the CompCams Blower cam in it. It would actually be better than stock. A "blower" cam usually has a profile that opens up the valves quickly and stays open longer to get maximum squeeze into the Combustion chamber.

If I remember Correctly (IIRC) the higher the duration, the higher the power band. Most automatic cams have low duration to create a wide power band to give the maximum HP over a broad spectrum. Automatics leave much lower than stick cars and usually only have 2 or 3 gears. Manual Trans cars, on the other hand, leave at a much higher RPM and keep the revs up, so there is no need to make power below 5000 RPMS. Here is a good example. GM (Chevrolet) had the famous 30-30 cam in the '69 Z/28 with the 302 engine. This was an entry level race cam of around .485 lift and duration in the high 200s. This cam was commonly called the phase 2 cam back in the day. GM also had what it called the Phase 3 cam for the 302 (I had one) and it had I & E lift of .500 with 320º of duration and a 120º split overlap. This is the cam that GM made available for Trans-Am racing with the dual quad cross-ram manifold. This cam was used where the cars were run in 3rd and 4th gear mostly and keeping an RPM above the 5000 mark. I used it drag racing with an Edlebrock TR-1Y tunnel Ram and two Holley 660 "center squirters" Because of the high duration and lobe center overlap, this engine did not "clean out" until 5200 RPM was reached it made power in the 5000-8500 RPM Range and I left the line at 8000 and shifted at 7500, 8200, 8200 and went thru the trap at a hair above 8000 RPM. The car went 11.50s all day long with a best of 11.46 ET @118 something. (67 camaro, 3000#, 5.57 gears, Muncie M-52 4-speed)

Automatic cams usually run in the 2000 to 6000 RPM band and durations hang in the 220º to 260º neighborhood.

Stick cams usually run in the 4000+ RPM band and duration can be anywhere between 270º to 330º. So, looking at the duration specs for the CompCams set and the ones for the GM set, it looks like the Comp Cams gives a nice broad power band from 1800 RPM to redline (6500) and the GM cams would be better suited for ( and I'm just taking an educated guess here) 3800/4000 to 6500+ RPM. My guess is without a rev limiter, these cams would make power well into the 7000+ range.

Good Point
I should clarify that the GM Performance parts for the ECOTEC are all designed to work in conjuction with each other, on a heavily modified 2.0 ECO running 30+ psi boost. With these cams JL achieved [email protected] rpm at the crankshaft. AND it want using the LSJ head, but at 6444rpm (the current RL rev limiter) the dyno indicated this engine was only making 611HP! So yes, while these cams are suitable for boosted,stick cars and will in general create more HP at higher RPM on any ECO- BUT these cams are designed to produce peak horsepower at a higher powerband than would be achievable with the stock rev limit and other "stock" internals .

The GMPP race components are of course very expensive and considered superior even to the LSJ but are still "based" on the stock components eg. CNC ported L61 head, specially sleeved block w/stainless steel O-ringed sealing, etc etc.

IMO about the only GMPP component that "might" have a very practical use by itself as a stand-alone mod on the LSJ would be the "blank intake cam (see my post above) AND the adjustable cam gear set PN# 88958613. This would provide a certain amount of adjustability (+/- 16 degrees) in the cam timing and powerband, so that, depending on the type of racing you do, you will be "on the cam" for maximum periods during competition.

Someone has certainly posted this before I'm sure but here's alink to the GMPP parts for the ECOTEC
http://www.gmgoodwrench.com/perfpartsjsp/partlist.jsp?cat=9284&section=pp

Also for anyone thinking of replacing your cams, there is a tool your dealer has that allows you to change them without any major dissassembly. Basically it bolts to the front of the head (once the cam cover is off) then you transfer your gears and chain to the tool so that your cams can be R&R'd without losing your cam timing. The J43655 holds your timing gears and chain and maintains their orientation while you pull the cams. Have used it personally and works great. If you need one you can buy one at 1-800-KMTOOLS, or maybe you can "borrow" it from your dealer, or fab one yourself. Here's a pic.

Regards
WopOnTour