Inliners International Forums General Discussion Hi Performance Offset keys available?

Are there offset keys available to degree a 261 cam? This is a question from my builder. We are working out what we are going to do with the cam. Currently looking at our options. Thanks for your help.

Dear Bert;

No there not. I looked into this in depth, in 2003 for one I was building.

The cams for those (216/235/261) are ground with this in mind and acording to the "top guy" @ Howards 'not to worry'.

Now; There's a guy in S. America that's making gears for the later 250/292 which are adjustable.

Does anyone know if 250 gears will work on a 261??

Old bert
why not reslot the Gear rather then trying to run a offset key. Most degreed timing gears have the Crank gear cut with 3 different degree settings.
Which is like 4after, zero and 4before TDC.

doesn't clifford make timing gears with multiple keyways?
robert

Cloyes makes the gear sets w/multiple keyways.
I think Clifford sells them also.

MBHD

B;

I looked for my notes on this, but no luck.

There's a timing gear set with 3 slots like Larry mentioned in an old Clifford Catalog. It has the same part number for the early/late engines which is; 92-3871.

This would indicate that they interchange.

The thing is that; 5,500-5,800 RPM is about 'max' for an early engine (no matter what) where the later ones go much higher (7,000+) which is what these gears/cams are for.

The center slot is probably what you'll end up with in the end. Spending the time/money on 'straping the mains' is a better choice as It's a proven practice.

The Esky E-2 or the Howard F 298 "rumpy" is the most you'll need cam wise.

Some head work will get you there faster and the straps will keep it together.

Good luck.

I've used Small Block Chevy V-8 offset crank cam gear keys in 261's and my current 302 GMC.These are custom one off cams that needed adjustments to fit the situation.
Generally speaking,a few degrees one way or another won't make a difference in a mild street engine,and adjusting the cam a few degrees won't turn a pig into a thoughbred,But you should always degree in a cam just incase the various "tolerances" of the parts stack up wrong.

T;

Agreed; This is why I advised him to go another direction.

Unless you have made an huge error somewhere, things can't "stack up wrong" and will be discovered in the normal assembly process W/O the need of 'offset keys', multi sloted gears or degree wheels.

This "degree business" didn't come about until super high lift cams were being developed for high rev experimental drag engines. Only in that 'world' is it a requirement.

John,old inline GM tuning books from Fisher and company mention it's best to degree in a hi performance cam,that was 50 years ago when .450 lift was considered full race.
Why not check all the variables on an engine one is building for a personal project?It's kinda interesting and the tools to do it are inexpensive.
Now, ya wouldn't intall new tires on your ride without checking the air pressure,right?lol.

T;

Yes It's mentioned & some actually spent the time to do it in the 50s & 60s.

However; after years experimenting, (hand made parts) the factory keyway(s) were what everyone used as 5,000+/- RPM wasn't high enough to get any real benefits.

With the 'later' engines which are capable of the higher speeds, it became a consideration again and many 'different' grinds have been tried in various timing positions.

Now; If (that word again) your building an engine that has a lot of new ideas/components, YES It's a requirement like you said. Almost all use proven (Pro made) parts though.

The area of experimentation today is with turbos/NOS as camshafts for racing have been "dialed in" @ the MFG test Lab. If a special gear/gears are needed they will sell them with the cam.

If one wants to spend the time on his own fine, but customers won't pay you to 'double check' the cam grinder..

Happy trails.

Last weekend I found Mr. Gasket offset keys hanging on the wall of the Sevice Center Speed Shop in Lomita Ca. I needed an adjustable pivot ball for my Lakewood Scattershield which they had. They are for Chev V-8 crank gear but the keyway is the same width. I use a TCI Balencer which fits in the first key and crank gear fits on the second. 2 and 4 degree. 6 months ago I bought a 3 keyway set #8-1016 from Cloyes. right off the internet. www.cloyes.com > high performance > page 11. Listed for the Late model but fit perfectly on my 1952 302 GMC. The Cam gear had the exact Cloyes # as my new set for the GMC which I purchased a few years back.

Cloyes is very helpful over the phone on their tech line. I originally called for offset keys and was told to use the #1018 set in my old engine. Just remember to dial in your cam with a degree wheel when you are done...I have found a Cloyes gear with the mark 1 tooth off which showed right at 15 degrees retarded.

Good Luck

Jimmy S;

Well: I guess I'll look into that when I put mine together.

When I last checked (2002) no one was aware of what you advised.

Bert;

If they fit the GMC they will your 261.

Thanks.

Great help. Thanks