Inliners International Forums General Discussion Hi Performance GMC 292 cam gear problem.

Hi everybody,
First post here. Building a twin turbo 292 base 340 6 cylinder.
This is actually a rebuild / conversion to a pump gas turbo engine.
The question I had is with the cam drive gears. I believe they are Cloyes brand with straight cut and adjustable (3 keyway) crank gear. I don't know how many mile, laps or hours are on these gears but they are fretting at the contact points. Is this common? Anyway to stop it? Are they okay to run or will I need a new set?
I tried to take some picture of just how bad it was but I need a better camera for that.

What is a 340 6 cylinder? How do you get that?


MBHD

I think if the gears are showing any signs of wear, you should go ahead and replace them, their not that expensive, and you will have peace of mind knowing they are new. Also curious about the 340 6 cylinder combo you mentioned.

4.130 bore x 4.25 stroke x 6 cylinders
It's a pretty serious build. All aluminum block, head, titanium rods, roller cam, etc. Don't ask where the aluminum block came from. There is no name or numbers anywhere on it.

"4.130 bore x 4.25 stroke x 6 cylinders"

Ah so . . . i get 341.6 cid. These are roughly the dimensions of Tom Langdon's bored-and-stroked GMC 302 . . . but an aluminum block! i am curious about that block, but even more curious about the head! This would be something that we all want to see.

God's Peace to you.

d
Inliner #1450

Rob,
Is that a cast or billet?

What head will you be running on it? We need pic's. Sounds like you are going to have a fun project. Tom

Here are some pics.
http://s749.photobucket.com/albums/xx135/BR_LSR/Govs_six2010/

You can see more at

http://s749.photobucket.com/albums/xx135/BR_LSR/Govs_six2010/

That' a huge advantage for the bore size: unshroud the valves.

Looks like a Duggan. Do you have the sideplate?

I agree, it's either a Duggan with the name removed or a Deppe. Same with the head.

Cool engine!

Those timing gears are shot.

What are you going to put it in?

The stroke on that crank is huge.

I think it may be a Deppe. Mr Sissell thought it was when I sent him pics.

Do these timing gears fail often like this or there an underlying problem that caused this?

Looks like gears that have ran without oil for a time. If they did run dry - it wouldn't take long for surface temps to get high and localized spalling to start.

Center to center distance looks a little tight on this gearset.

Well to make a long story short. I delivered this engine 7 years ago but it never got installed and running.
I now have that task of mounting turbos, building headers, manufacturing intake manifold, installing FAST XFI fuel injection and get it up and running and dyno tuned.
It is getting close to firing up. A big thank you to Mr Sissell for all the technical help!

Anyhow,
I had a question about the front timing covers for these engines.
What actually locates the cover to the block? Chevy V8 uses two small dowel pins. I'm afraid that if it is not located correctly, the front seal will leak.
Pics to follow.

Untitled by CarbiniteLSR, on Flickr
Untitled by CarbiniteLSR, on Flickr
Untitled by CarbiniteLSR, on Flickr
Untitled by CarbiniteLSR, on Flickr
Untitled by CarbiniteLSR, on Flickr
Untitled by CarbiniteLSR, on Flickr
[img]https:
[url=https://flic.kr/p/21S6QHw]Untitled by CarbiniteLSR, on Flickr

1/2" diameter hole in cover is for cam sensor. Corresponding magnet shown bottom pic.

Professional engine builders have specialty tools they make or buy to accomplish this task. I have many for different engines that range from old balancers with the outer ring pushed off of them to billet hubs with keyway's broached in them i've made to slide on the crank snout to take the place of the balancer that will center the timing cover.
You will have to loosen your oil pan because it being snugged up into position already can/will force the timing cover out of center regardless of any method you use to center the timing cover.

I've always done like CNC says. Use the damper or simulated damper hub to center the timing cover, then install oil pan.

Use the damper pulley, thats the only accurate component since that's what needs to seal to the cover. Nothing else matters.