Adjustable Cam Sprocket

Randy N Connie

Registered User
Would anyone know if some one makes an adjustable timing chain cam sprocket?

Are there any aluminum belt drivin timing pullies being made?
And with the cam pulley being adjustable?

Are they any V-6 Stang people using these type parts?
Chain or belt drivin with adjustable timing.

Thanks Randy
 
Tom Morana

Go to the links section and go to Morana Racing. Tom makes a adjustable cam timing sprocket that has (I think) 3 degree increments.


Don
 
Randy,

Like most adjustable timing sets, the Morana one uses extra keyways in the crank sprocket and not the camshaft sprocket. Kurt K. has one of his newer style timing sets in his motor. After seeing how much the chain stretched on his initial Morana timing set, I decided to stick with the stock chain and tensioner and use a chip to compensate for any extra advance or retard from the reground cam.

Now that Comp Cams is offering new blanks, you can have the cam ground with whatever advance or retard you want and use a stock timing set.

David
 
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When i installed my regrind it degree in at 105ICL. The cam card said 112, so it was advanced by 7 degrees. What i did was machine a new keyway in a stock style timing set, 3.5 degrees off from the old keyway. The ratio is 2:1 so that makes up for the 7 degrees. The new keyway was placed 180 from the old one, in a reference of 3.5 degrees. When i finished it dialed in at 113 ICL, so my placement was only .5 degrees off(2:1 ratio). I used CAD to figure out the placement, and made some new parts for a broaching kit and cut the keyway. It took some head scratching, but it was do-able.
 
I need an adjustable cam sprocket.I wouldn't be interested in a
broached sprocket.

When I get time I will try to machine me an adjustable sprocket.
I might be able to cut one up and fab a new center.

It would be nice if small block Ford timing parts would fit.

Thanks Randy
 
I would like to score a belt-drive with aluminum pullies.
With cam pulley being adjustable plus or minus.

I wounder if there would be any Ford small block parts.
That could be addapted to use with the SC-bird 3.8
crankshaft & cam .

If the small block parts would be close to fitting.
It may be worth doing some extra machine work
to make a belt drive fit the SC block.

I would like to try a adjustable belt-drive to save weight.

Randy
 
Randy, I give a double thumbs up for you to come up with an adjustable system. Can't say I would want to deal with a belt over a chain, but regardless, I feel it would be a great product.

Paul
 
David Neibert said:
Randy,

Like most adjustable timing sets, the Morana one uses extra keyways in the crank sprocket and not the camshaft sprocket. Kurt K. has one of his newer style timing sets in his motor. After seeing how much the chain stretched on his initial Morana timing set, I decided to stick with the stock chain and tensioner and use a chip to compensate for any extra advance or retard from the reground cam.

Now that Comp Cams is offering new blanks, you can have the cam ground with whatever advance or retard you want and use a stock timing set.

David
I don't remember the chain stretching, I just remember all of the aluminum shavings :mad:

I'm thinking about pulling the cover and advancing the cam again (back to the original build specs). But it will have to wait until after Carlisle, before I tear into the engine for any reason.
 
I dont see any disadvantage to just adding two more keyways in either the cam or the crank sprocket. You will still get the adjustability as a set from Morana, and still keep the stock style and tensioner. I could be wrong, but adding a keyway worked perfect for me, and you have the ability to add as many that can fit.
 
There are other reasons to use an adjustable system. For one thing, the more keyways you cut into the crank gear, the more crank wear you will see from it. Some of the many-keyway gears have ruined cranks.

Another reason is simplicity. Being able to adjust timing without pulling the gears is a nice feature. A properly made system in conjunction with an electric water pump could possibly allow timing changes without as much as pulling the cover. Not THAT starts to make sense.

Belts have less friction, weigh less and I think stretch less than chains, but not sure on the last one. Anyway, I think the biggest problem might be how to keep the oil out of the belt. I'm guessing you'd have to make a plate that seals up the front of the motor and then run a seal on the cam spacer. Not sure how you'd lube the cam sensor drive though or drive the oil pump.......

Starting to get complicated. :mad:
 
Dave makes some good points. I'd like to note that I added my keyway on the cam sprocket. I was able to achieve the desired results and I don't see a personal need or all that much benefit messing with cam timing often. But don't get me wrong, I'd love to see some new designed parts.
 
Dave D. Has pointed out the direction that I am thinking in.
Since I have a electric water pump that I have already fab
up.I will not have a lot of trash on the front
of my new motor.

There is enough room to adjust a cam sprocket,and get
by the cam sensor drive.The 3.8 timing chain cover can
have a hole cut into it,lined up with cam center.A machined
bung can be welded into the chain cover.A machined
plate bolts to the bung to seal the timing chain cover.

I beleive a setup could be made that would only take
15 minutes to adjust the cam.This would be nice for
tuning for different setups.

And it is just fine to run a belt drive in oil.But I have heard
at very high RPMs a belt can surf on the oil just before
hitting the cog on the pulley.Raising the belt up above
the cog on pulley.This system would not be turning that fast.


If the small block parts could be modified to work with
the SC 3.8 An adjustable pulley would be a good tool
to have for a all out balls out built SC motor.

Paul thanks for the thumbs up offer.But I would not
want to produce ,what I am kicking around.If it was
cheap enough to get a complete timing belt drive .
That would not take much machine work to convert
to bolt on a SC 3.8 motor.It looks to be easy to fab
the stock timing chain cover. To hold a bolt-on and
sealed inspection cover to acess a adjustable cam
pulley.If somthing like this would work out.I would
probably make 2 or 3,two for me,and one for hoo-ever
would help a project along.Same as I have always done.

I am not going on a diet,so my car will have to take
up the slack. I need lighter parts. :)

I thought maybe someone would know if other Ford or
even chevy performance adjustable aluminum timing
pulley systems.Might be a close enough to the 3.8 motor
to alter to fit.

Thanks Randy
 
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Dave N.

I hope you dont really think you can compensate cam timing with a chip.

The original Morana chain setup didnt clear the timing cover which is the big problem..Thus teh metal shavings..I believe it was the allen head bolts.

Would be nice to have a true double roller for our cars that didnt have to be rigged


Randy,

As far as a belt drive is concered Ive run them with 8oo lift and 7500 rps with no problems...Actually the best setup you can get....If someone were to just make one work with a 3.8
 
DamonSlowpokeBaumann said:
Dave N.

I hope you dont really think you can compensate cam timing with a chip.

The original Morana chain setup didnt clear the timing cover which is the big problem..Thus teh metal shavings..I believe it was the allen head bolts.

Would be nice to have a true double roller for our cars that didnt have to be rigged


Randy,

As far as a belt drive is concered Ive run them with 8oo lift and 7500 rps with no problems...Actually the best setup you can get....If someone were to just make one work with a 3.8

Damon,

No I don't think a chip can compensate for cam timing, but if it's only a couple degrees off, it only shifts the power band up or down by a couple hundred RPMS, so the chip can help by increasing or retarding ignition timing and adding or removing fuel. Then there is always overdriving the blower more or going to a looser lighter converter (both in my case).

Kurt,

That first chain was streched, not much but it only takes a little to allow the chain to get slack. Maybe it got loose from all the rubbing, but I just don't like the idea of not having a tensioner.

David
 
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DamonSlowpokeBaumann said:
The original Morana chain setup didnt clear the timing cover which is the big problem..Thus teh metal shavings..I believe it was the allen head bolts.

Would be nice to have a true double roller for our cars that didnt have to be rigged
Yeah Damon, the allen head cap screws were replaced with counter-sunk allen head cap screws. I agree that it would be nice not to have to hobble something together.
 
Sorry

Not to bring up a old thread, but, has anyone tried the 3.8 SVO timing chain form Cloyes yet? Its a "True Roller" with three keyways for 4 degree's advance or retard. You can get them from Summit for $120, I found that out to late and spent $185. But then again, if it don't work I can just send it back to the place I got it.

Unless someone has already tried it, and the tech guy at Cloyes said it would work, I'll let you know how it goes in a few weeks.
 
I am still looking for an aluminum cog pulley timing set
with belt drive.That I can machine to work with the
3.8 SC motor.

My concern is weight savings more than the adjustable
part, But why not have both.But I have no interrest in
multi spaced broached keyway spockets.

Thanks Randy
 
Hock said:
Not to bring up a old thread, but, has anyone tried the 3.8 SVO timing chain form Cloyes yet? Its a "True Roller" with three keyways for 4 degree's advance or retard. You can get them from Summit for $120, I found that out to late and spent $185. But then again, if it don't work I can just send it back to the place I got it.

Unless someone has already tried it, and the tech guy at Cloyes said it would work, I'll let you know how it goes in a few weeks.


I'm definately intersted in that setup!!!
 
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