87 replies to this topic

[N/A-PWR]

Great 41cc size Brian,

 

 and you still have the open chamber look.

http://www.gmh-toran...e-2#entry947166

[N/A-PWR]

Oh, sorry Brian,

 

 I jumped the Gun, but you will have no Valve to Piston issue's then.

That other head look's good still in the chamber area, as I achieved 44cc at 100 thou shaved. 

[ribz0]

Nice build!!

I have done the same... had the blue motor built for a while but its finally in and just doing the small stuff now.... Mine is out of a VC commodore and has come together nice....

Always looking forward to the start up...

Cheers

[N/A-PWR]

Thank's for the update Brian,

 

 the thing's you have to do for a great outcome.

 

 

 

 

Like button for the dremel work 

[N/A-PWR]

Should have a some poke,

 

 will be an eye opener for sure, once the rev's get up.

[I'm a Red Motor fiend]

Good stuff mate. Nothing like firing a fresh combo you have devised and built yourself...

[warrenm]

Well started her up today, have set the timing at 16 static at this point , with the modified dizzy in it, max advance will be 30-32, so should be close, oil pressure is a little high at 60-65, I will see how that goes, might need to drop it back a bit it, running on 15-40 mineral oil,

I wouldn't be worried about dropping it, it shouldn't rob much horse power.

Did you space the relief spring in the pump or is it tight clearances?

[yel327]

Not bad for a single carb 202 daily driver. Based upon factory published SAE Gross versus rear wheel dyno figures I've seen for other stock GMH products (mainly V8's) I'd say you are looking at a ballpark 190hp SAE Gross (or GM1 test in GM speak). A stock HT-HQ or LH 253/4.2L high comp engine is 185hp@4400rpm SAE Gross and you are bettering that. With a bit more sorting of fuel and timing you may easily crack 200hp which is what GM SAE Gross rated the 307 we got in HK-HG. As Bomber says it probably goes really well, especially if you have a 6cyl manual diff in it still (like a 3.36) and 13" wheels, will go like a rocket! The 4.2L versions mainly had 2.78 or 3.08 rear axles. 

[yel327]

Mick, I'd say you pretty much confirmed GM and GMH GM1 figures are right other than the stock red 202. In the stuff I've seen rear wheel hp usually is ballpark 2/3 of the GM1 test for a manual car. For the XU1 120hp rear wheel and 190hp GM1, that is close enough to 2/3 allowing for individual dyno variances. Same with the HT GTS350 manual, 200 rear wheel hp is 2/3 of 300hp. The mid 15's for a manual HT are road tests from specially prepared GMH cars, a properly tuned HT GTS350 will do high 14's but that info never made it to Press in the 70's. It was never covered properly until AMC magazine tested a Survivor car about 6-7 years ago, that car still even had its original clutch in it when tested, it was that original.

 

Remember the GM1 test is performed at full throttle using lab quality fuel, controlled air pressure of 29.92" Hg, 60degF ambient temperature, running with exhaust manifolds into the dyno's exhaust system, no fan, alternator freewheeling, optimum spark advance and optimum fuel settings. So the engine is able to produce as much power as it ever could.