Inliners International Forums General Discussion Engines Langdon's 292 Marine Cam?

Anybody using Langdon's 292 Marine Cam?

I'm thinking of using it in my panel truck.
Engine is a 292, mostly stock, 2 1/2" exhaust manifold.
Maybe a 390 Holley on a Offy intake.
Going in a 1961 C30 Chevy panel truck, 5.14 rear with a truck 4 speed and a Advance Adapters Overdrive unit.
I'm getting 60 mph @ 2400 rpm if I did the math right.

Thanks.

Pete

Let me start by admitting that I do not know the first thing about a marine cam for the 292 or what the specs are.

BUTT: I have dyno tested many camshafts on Brand F V8 engines and found the cam made for marine use to be lacking sufficient low end performance and part throttle pulling ability to be useful on a car. Too much overlap and too late of an intake closing event.

Marine engines generally are tuned to run best at higher speeds and higher loads than what car engines usually run. So a low end lugger will not want a marine type cam.

Again, my comments are a generalization, not specifically pertainent to a 292 with a 292 marine cam. Just food for thought.

can you supply the cam specs? i believe it is just a step up from stock. should make lots of tq. tom

the specks on a 250 marine cam are like a 437/439 with a duration like a 204 An a 112 lobe seperation.So i dont think one for a 292 would be much different.So personaly I don't feel that it would be good enough for a druck for sure.
The 112 lobe seperation is fine But i feel you would need something more in the Low 500 lift range.Rpm band from idle to 5000/5500.
Just my personal 2cents

The camshaft specifications for the two different "Marine" versus "H.O. Marine" are quite different. For full details of the Langdon "292 H.O. Marine" camshaft, you really need to speak with Tom Langdon, or someone that has run his camshaft. He does not give the 0.050" duration, which is much more meaningful than total duration specifications. OEM manufacturers camshafts usually have much slower loading ramps and lower lobe profile accelerations to minimize wear, extend camshaft and lifter life. Total maximum total lift is also usually lower to reduce valve spring fatigue. The OEM engines must run multi 100,000's of miles with next to zero failures.


Chevrolet/Mercrusier 250 "Marine" ...288/288 total duration, 0.403/0.403 total lift, 192/192 0.050 duration, 112 lobe seperation
Langdon "292 H.O. Marine"..............262/262 total duration, 0.442/0.442 total lift

Aftermarket camshaft manufacturers usually run much more aggressive ramps rates so the 250 Marine (OEM style) total duration of 288 degrees cannot be directly compared with the Langdon 292 H.O. Marine total duration of 262 degrees. As a relative comparison, the Comp Cams 260H cam lists a 260/260 total duration, 0.489 total lift, and a 212/212 0.050 duration.

Tom Langdon, having spent his long GM career testing inline GM engines, balances performance and long term reliability. As a note, he limits his valve lift to 0.442" to meet long term fatigue stress limits on the stock valve springs.

Thanks for the responses.
The specs I got from Tom are:
.442 lift and 260 degree duration.
This truck is going to have plenty of gearing so no lugging should be necessary.
I'll have to check out the Comp Cams camshaft.

Thanks.

Pete

I agree with Frenchtown...The Mercruser cam I had in my 250 will out top end (mph) anything i have had in my car. Pulled like a bear from 2850 to 4700 and out of snuff at 5000. You can over cam these motors real easy even with a good build. The head just will not flow those big cams and ragged around town. I want to try something in the 268 duration range and about 525 lift. If this don't work out my Merccruser is going back in.!!! I have lost 11 mph and the 350/350 crowd is loosing respect for me.