General kinetics "info"

[Caperat]

I have two General Kinectics -- smallblock Chevy roller cams for superstock application from when i believe is the mid 70's that i would like some information on. The lobe sep. is 106 degrees, they are stamped G K -- Detroit, 308/434, C/R, #13961. Would anyone know the lift, duration @ .050, valve lash, RPM range, or the # of the correct valvespring. Any information would be greatly appreciated.
Thankyou very much.

[Rich Biebel]

I used a GK 308 cam in 1980 in my 350/255 Camaro. I am guessing at the lift and the 434 usually would mean that was the lobe lift. Multiply your rocker ratio times that 434 number and subtract the lash. 308 is the advertised duration and @ .050 I'd have to guess was around 280. My GK was a real parts breaker.....it came thru T/K's and Ralph Truppi and was tested and ran real fast in some other cars. Not mine though! I broke rocker arms,valve springs and stopped using that GK cam because of the breakage. Mine was a regrind so maybe that is why it broke a lot of parts. Too much flex and the rockers and springs were not good enough...... A Cam Dynamics 316-321 worked much better for me......

[rich freitag]

Hi,I have old books that get better with age,I have 2 general kinetics books,i found your cam,308/434R advertised dur 308 dur@.050 280 lobe lift .434 Lash is .017 I hope this will be a big help,Rich.

[ss wannabee]

Rich, a friend of mine also ran a GK roller in a '55 Chev SS car about the same time you had the Camaro... He also had similar breakage problems and switched to Cam Dynamics, like you.... Do you recall what valve lash you ran? His cam card said .036" hot which he thought was a bit extreme and might be causing the breakage... .the CD cam's lash was tighter and the breakage did seem to quiet down after swapping... I would think that guys GK cam would be good for about 8200 rpm if everything else is set up properly, wouldn't you?

[ss wannabee]

Caperat, my friend has an old GK catalog also and says that .017 figure is something GK called "cam lash"....NOT valve lash...to get the proper valve lash, they say take that figure and multiply it by the rocker ratio you're running...which means that valve lash would be in the .025"-.027" range.....No mention of valve spring pressure though.......

[Rich Biebel]

GK cams were very popular but had a reputation for breaking parts. I probably ran .025" or so on the lash on that GK 308. I broke Sig Erson aluminum rockers, they were not very good. I had a set of heads that came from John Lingenfelters shop originally. They had 1.550 springs on them. I cut those heads for 1.625 triples, hit water doing that machining operation. Epoxied them up. I hoped those big springs and various other upgrades would help.....they did not. I was racing a S/SS race one day and went a few rounds and the car was slowing down.......when I pulled the valve covers, and that was done constantly in those days, I found 6 broken springs. I also broke rocker arms and sent one thru a valve cover one day. That car ran SS/JA and my best run was 11.20 at 118+ in the early 80's. My last run ever in that car as a SS'er.....I raced Bobby Warren.....I was toast there.....

[FED 387]

General Kinetics definately are/were spring eaters you have to check them after EVERY pass to be safe BUT they do/did work--Contact Harold at Cammotion in Missiippi he is the guy that was GK --Harold is a little wierd but his stuff works--Comp 387

[Caperat]

Thanks a million guys for all the information. --

[Caperat]

Originally Posted by rich freitag

Hi,I have old books that get better with age,I have 2 general kinetics books,i found your cam,308/434R advertised dur 308 dur@.050 280 lobe lift .434 Lash is .017 I hope this will be a big help,Rich.

Hey Rich, could you please tell me the advertised intake and exhaust lift for this shaft. --- Thanks

[Rich Biebel]

.434 is the lobe lift......so .434 x 1.5 = .651 - whatever lash you use. .434 x 1.6 = .694 - the lash......It was pretty common to run 1.6's on the intakes and 1.5's on the exhaust.