[Scott McDonald]

I finally got to really look at the GT this weekend as lots of personal stuff kept cropping-up. Still don't have a digital camera, and my computer @ the house carked. So I can't provide photos.

The engine is around 2.2l with aluminum domed pistons, floating shot-peened rods, and a stroked crank. Compression about 11:1

Head has a "quickie" porting job by Mr. Legere. Also has doubled springs with a 3rd spring-like thing which rides in the middle of the two outer.

Got an Isky Combo Cam since my others: had a lobe that went missing, or produced compression too high for pump gas.

I had to recurve the distributor as pinging was bad, not as bad as with the stock cam I have, but still bad. So, I put 2 heavy springs in the distributor, and added shims around the spring post to limit total advance. The problem was that to eliminate detonation I had to substantially limit total advance. The result was an engine that was very lethargic.

Tell me if this makes any sense, and why it seems to have helped, as I haven't a clue. I unset my vacuum advance which was @ 0°, to total retard. Then, I added some total mechanical advance.

On brand name 93 Octane, AND "Off-Road Use" Octane Boost (+2 octane), I can control detonation. However, if "off brand" gasoline or "street legal" octane boost are used- detonation will occur, it will ping @ startup, and/or it will get a horrible case of run-on.

If you think it will cure my problem, I have one of those thick Risse 2.0l head gaskets to lower compression. I am leery to use it, as it is the last head gasket I have, head gaskets were hard to find last time I checked with OGTS, and I don't want to put it on just to find out it didn't work as well as expected and solving naught.

I could buy another solid cam, but solid lifters are becoming uncommon lately.

 

[N61WP]

Scott, do you have a "dial back" timing light? You need to know what advance you are starting with, where it starts to advance and what the total advance is. You should only need 34-36 max. You say you disconnected the vacuum advance...did you rivet the plates together?

Forget about changing your compression. You should be able to get it sorted out like you have it.

Bestus,
James

 

[RallyBob]

The Isky combo cam is way too small for that compression ratio. You need substantially more duration, and preferably a narrower lobe separation angle.

First of all, you're giving up power from retarding the timing. Secondly, with that compression and head you're giving up a lot of power just in terms of matching the cam to the engine specs. Probably 25 or so hp. That's a lot.

I'd shoot for something with 245-250 degrees of duration @ .050" and 108 lobe separation to let that thing breathe a bit better, and reduce cylinder pressures a bit at low rpms.

Bob

 

[Scott McDonald]

I have close to such a cam (240 duration @.50, but 104 deg lobe separation), although, I need to have the 1st lobe remade. Would you have a suggestion as to who could do that?

 

[Motor Mouth]

Hi Scott,

These aren't solutions to the problems but should help with some of your worries.

I can source head gaskets and lifters if the 'US' owners are worried about getting them and am happy to ship to the states, just ask Gary

As for cams, I have a couple available and these should suit a 2.2 if you're interested. Check out ebay.co.uk and do a Opel CIH search and you'll see I have a Piper 285 currently for sale.

 

[tekenaar]

Dying to see it . . .

So WHEN are we going to see this MONSTER, Scott?

All kidding aside, you need to bring it to the next TX meet, running or "not quite" . . . whatever!

 

[RallyBob]

I have close to such a cam (240 duration @.50, but 104 deg lobe separation), although, I need to have the 1st lobe remade. Would you have a suggestion as to who could do that?

Cam Techniques restores cam lobes for vintage engines. I have had damaged Opel racing cams 'rebuilt' this way, they can weld up a new lobe (cobalt hardface...much harder than the rest of the cam!) and regrind it to match the originals. It's been a while, but I believe it cost me about $50?

HTH,
Bob

 

[nobody]

Having gone down this road, might I suggest a fresh billet from OGTS? When we last talked Gil was selling them for 75. Ship it and your lifters for a conical regrind to San Diego. New billet cam and regrind of lifters for probably 200. Oh and if you ask nicely Ron aka Namba 209 lives very close and can check it out.

http://www.schneidercams.com/

oh the main picture is who does my motor work

 

[BetaCarotene]

yesterday i sent my cam and lifters there shipping was around 24 bucks. cam cost 100 bucks and 3.50 a lifter