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Adjustable Cam Sprockets?

Posted: Tue Jan 25, 2005 9:41 pm
by All_talk
Any available for the EJ22/EJ22T?

Gary

Posted: Tue Jan 25, 2005 9:45 pm
by douglas vincent
no

Posted: Tue Jan 25, 2005 9:53 pm
by tris91ricer
..and doug is semi-authority on that one. He's designed pulley upon pulley for his SC setup. Why would you want adjustable?

Posted: Tue Jan 25, 2005 10:19 pm
by douglas vincent
Actually, they have been made, but custom and uber exspensive. Nothing off the shelf is available as far as I know.

Posted: Tue Jan 25, 2005 10:20 pm
by All_talk
douglas vincent wrote:no
Simple question, simple answer... I like that. :D

Next question...

How many people would like adjustable cam sprocket for the EJ22/EJ22T?

Recently prototyped one for the older EA82/EA82T engines (see pics), and am considering a small production run after some testing. In researching the potential market for them I became aware that there seemed to be none for the EJ22. This actually surprised me as it seems to be a good size market.

Anyway, a few more questions…
Do the EJ22 and EJ22T use the same sprocket?
Do other SOHC engines use this sprocket as well?
Adjustable sprockets are great to get the most from aftermarket cams, are there any Hi-Po cams out there for the EJ22?

Image

Image

Image

Let me know what you think.
Gary

Posted: Tue Jan 25, 2005 10:22 pm
by Brat4by4
Weight difference?

Posted: Tue Jan 25, 2005 10:30 pm
by All_talk
Brat4by4 wrote:Weight difference?
The stock EA82 part is about 9oz, this steel prototype came in at 12oz, but the production unit will have an aluminum hub and should be at or below stock weight.

I dont have a EJ car (yet) and I'm completely unfamiliar with the sprocket they use, so I can say what the adjustable unit might be. Anybody have a pic of the EJ22 sprocket or front of the engine with the cover removed?

Gary

Posted: Tue Jan 25, 2005 11:22 pm
by petridish38

Posted: Wed Jan 26, 2005 4:59 am
by Legacy777
The cam pullies are the same for the EJ22 & EJ22T.

Posted: Wed Jan 26, 2005 5:22 am
by THAWA
What is the point of this?

Posted: Wed Jan 26, 2005 6:38 am
by evolutionmovement
Adjust valve timing.

Steve

Posted: Wed Jan 26, 2005 3:34 pm
by Brat4by4
If they are significantly lighter, I would be interested in them when I change my timing belt at 200k.

Any chance of making a pure lightweight version of the pulleys? Lighter rotating mass is free horsepower (more correctly freed-up, but hey.)

Posted: Wed Jan 26, 2005 6:54 pm
by scottzg
You can gain some top end power by advancing the cam timing, albeit not all that much. If you mill your head or put on a thinner head gasket, you can use these to prevent the cam from becomming retarded.

Posted: Wed Jan 26, 2005 7:19 pm
by All_talk
scottzg wrote:you can use these to prevent the cam from becomming retarded.
Your language is quite offensive… today cams are not “retarded”, they are advance impaired. :P

Andrew, thanks for the pics. Looks like it would be tough to reuse the stock EJ22 pulley’s outer tooth section with a new hub like I did with the EA82. I’d need to inspect one to know for sure, but if I have to start with a blank indusial pulley its gonna drive the cost up quite a bit.

Brat4by4, you looking for a light weight EJ22 pulley without adjustment? Or one for the EA82?

Gary

Posted: Wed Jan 26, 2005 8:23 pm
by Brat4by4
EJ.

But now that I think about it, I will be eventually building a H.O. EA82 possibly in the future...

Posted: Wed Jan 26, 2005 8:45 pm
by petridish38
All_talk wrote:Andrew, thanks for the pics.
Actually, they are Josh's (Legacy777) pics, I just linked them. Just thought i'd give him credit for his wonderful documentation.

Posted: Thu Jan 27, 2005 3:49 am
by THAWA
wouldn't it be cheaper to just change where the pulley is in relation to the belt?

Posted: Thu Jan 27, 2005 4:37 am
by douglas vincent
But not easier or quicker by far! Watch them Honda boys adjusting their V-techs. Now imagine you yanking everything in the pits essentially to do a timing belt replacement.

Posted: Thu Jan 27, 2005 4:53 am
by THAWA
Wouldn't you have to do essentially the same thing as a timing belt job, just not remove the belt? With the adjustable setup I mean.

Posted: Thu Jan 27, 2005 5:59 am
by All_talk
THAWA wrote:wouldn't it be cheaper to just change where the pulley is in relation to the belt?
I'm not sure I get what you mean?

Gary

Posted: Thu Jan 27, 2005 6:43 am
by douglas vincent
Not really if you just cut out the plastic covers.

Posted: Thu Jan 27, 2005 8:04 am
by THAWA
Oh I see. but why could you cut the plastic covers, instead of just removing them?

Posted: Thu Jan 27, 2005 11:31 am
by dzx
I don't think lighter cam sprockets would really make a difference. The crank and the flywheel both spin at way higher speeds so its understandable why you would want less weight on them.

inertia x omega^2

I think thats the equation but i dont remember for certain right off the top of my head.

Posted: Thu Jan 27, 2005 12:37 pm
by petridish38
All_talk wrote:
THAWA wrote:wouldn't it be cheaper to just change where the pulley is in relation to the belt?
I'm not sure I get what you mean?

Gary
I think he means to have the timing belt a tooth or two off.... But it seems that doing that wouldn't allow for fine adjustments :?
THAWA wrote:but why could you cut the plastic covers, instead of just removing them?
Removing them probably would work better since they come off on each side with like 3 bolts each, exposing the cam sprockets.

Andrew

Posted: Thu Jan 27, 2005 4:08 pm
by All_talk
petridish38 wrote: I think he means to have the timing belt a tooth or two off.... But it seems that doing that wouldn't allow for fine adjustments :?

Removing them probably would work better since they come off on each side with like 3 bolts each, exposing the cam sprockets.

Andrew
Now I see, Given the 24/48 tooth count on the crank/cam sprockets moving one tooth on the cam would give you 7.5 cam degrees (14 crank) of advance/retard, like you say not a fine enough resolution, and even one tooth would probably be to much for all but most extreme setups.

I would think you would run without the front covers during tuning, be that dyno, strip or other and once you have it dialed in you could but them back on.

Gary