I popped off my exhaust cam sprocket this morning, grabbed a good protractor, and measured out timing points so that i could retard the cam 1/2 a tooth (360* / 49 teeth = 7.3469387755102040816326530612245* . . . . and 7.3469387755102040816326530612245* / 2 = 3.6734693877551020408163265306122* or around 3.7* retard). I then, using the proper diameter bit, drilled a hole in the corresponding spot so that the cam dowel would slip right into place at that 3.7* retard. I confirmed my ignition timing and noticed that my idle was a bit lopey . I'll show pics as soon as i find my usb cable for my camra.

I noticed a drastic improvement in midrange throttle response and my knock count actually dropped from 15 counts at 5000 rpms to under 10 (i don't know why). I had been reaching full boost (15 psi, Small 16G) at 3900 rpms. But now I can hit full on at about 3100 to 3200. I wish I had gone to a dyno before so i could get some concrete numbers for everyone... but all i have to say is that for a free mod plus time (d@mn cam sprocket bolts) you can't beat it. !!!!

That sounds pretty interesting. When I bought my car my exhaust side cam was off and once I set my ignition timing again (after doing a timing belt) I noticed a rather large decrease in performance. I was off almost 2 complete teeth though which is quite a dangerous spot when you are playing with interference engines. Get pictures though as soon as you can, I am kind of interested to see what your cam gear looks like now. How many degrees of base ignition timing are you running?

I am running just over 6* BTDC base.

I too was in a similar predicament... i got the car with a "recently replaced timing belt and water pump"... the guy sold it because he was fed up with it he couldn't get it to idle right and it knocked all over the place. i said screw it, bought the car and bought a scanmaster. all for under a grand... car ran very, very strong until it started knocking. I got upwards of 40+ counts at times!!!! checked my timing, i was 15* advanced instead of 5*. That accounts for the knock but what about the lopey, rough idle? so i decided to check the cam timing. i was retarded one tooth on the exhaust, and advanced one tooth on the intake... so i set the cam timing dead on... and the car idled like a sewing machine but it had no real pull down low like it used to (by the way with the intake cam advanced one tooth. it threw off my ignition timing so it fixed two things at once). So i thought about it, and researched it, and decided to retard the cam just on the exhaust side... i had heard that one tooth retarded is better than stock but a little too much so i just put her in the middle and now i have insane top end and mid range and no loss of low end pull. i can mush around town and still feel like i have a quick car. i reach full boost almost 1000 rpms sooner.

Now, I really do accidentally burn out and scare people.

yep retarding the exhaust cam a few degrees supposedly give you a little power. I had a thread about this a little over a week ago, and since I have adjustable gears I will try and retard mine around 4 degrees.

Nice. I was going to do this very thing until I can afford a set of new cams. Definitly would like to see some pics of this. Did you also remark your cam gear so you could know for sure it was timed right?

Maglin said:

Nice. I was going to do this very thing until I can afford a set of new cams. Definitly would like to see some pics of this. Did you also remark your cam gear so you could know for sure it was timed right?

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Well you would have to use the stock marks on the gear to time it and the new hole for the dowel is what will serve as the method of retarding. He would basically time his car just like we would ours ( same marks )

what would happen if you retarded it on a set of 272's or the cam i more interested in fp2's.. would you notice any gain?

it may be worth while to get adjustabel gears just for this purpose.

instead of sitting around 1 day retarding your exhaust cam, you should probly figure out why your driving around with 15 counts of knock, and a small16g that isnt hitting full boost untill 3900rpms.

Dont blow 200$ on cam gears so you can retard the exhaust cam a few degrees. Get them so you can degree your cams CORRECTLY.

Most aftermarket cams are designed to provide the most amount of power when they are installed straight up. The HKS's and especially the Web cams are sometimes not degreed properly and need to be degreed to be straight up which requires the use of adjustable cam gears. The FPCams have stricter QA standards and are supposed to be centered already and not needed to be degreed.

I wouldn't retard a set of 264's cause if you do you might as well have gotten the 272's.. And the FP2's are designed to provide the power curve of the 272's with a good stable idle. By retarding it's ext cam you will get a horrable lopy idle that is hard to control.

Hope this makes some sense... I'm dead tired and about to hit the sack..

anconover said:

instead of sitting around 1 day retarding your exhaust cam, you should probly figure out why your driving around with 15 counts of knock, and a small16g that isnt hitting full boost untill 3900rpms.

Dont blow 200$ on cam gears so you can retard the exhaust cam a few degrees. Get them so you can degree your cams CORRECTLY.

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Instead of sitting around 1 day telling people to or not to purchase parts for their own car, maybe you should realize that i have not purchased any cam gears, i have modified the stock gear. i know why i'm at where i am at with my tune... i have no money now but time so i can't get 680s and a piggyback but I can retard my exhaust cam until then...

Maglin said:

Nice. I was going to do this very thing until I can afford a set of new cams. Definitly would like to see some pics of this. Did you also remark your cam gear so you could know for sure it was timed right?

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Actually, yes I did... To use the marks aready on there, it would cause the newly drilled hole to be too close to the stock hole. it would overlap, probably compromise the integrity of the cam gear, and i don't fancy breaking the cam gear on a hard pull past 4500 rpms :thumbdown: . So i just started fresh. the cam dowel is exactly 90* to the marks on the gear stock. so i just started at about 10 teeth clockwise and set it at 93.7 degrees from new marks. I use those new marks to time that gear with the crank and other gear.

P.S. I also want to clarify. I don't push the pedal past 75%. I know a small 16G is supposed to get to 15 psi (around 100,000 rpms) quicker than that with xylene in the tank i could get her fully on at under 2500 engine rpms . I am getting knock due to a lean issue. I have narrowed it down to clogged injectors or weak fuel pump. I have my walbro 255 HP but no AFPR yet

Still no success with a camra cable. So here is a scanned image of my template I used to do this:



I used a cd because the center hole is very close in diameter to the cam gear mounting hole.

1. Place the cd flat in the driver's side of the cam gear and drill a hole exactly where the cam cog hole is. Be sure that the cd hole is centered with the cam gear mounting hole.

2. Rotate the cd inside the cam gear so that the drilled hole is some distance away from the stock cam cog hole. Make a line on the cd that intersects with the center of the cd hole/cam mounting hole, the newly drilled hole and the middle of two teeth on the cam gear. With an accurate protractor, measure out 94* clockwise on the cd. It should come in between two cam teeth closer to the second tooth going clockwise. Mark that spot on the cd this is your right timing mark... mark this spot on the cam gear carefully and accurately (I used a hacksaw blade).

3. Take a straightedge and draw another line on the cd where the center of the cd hole and the right timing mark intersect. Bring this line all the way to the other side of the cd this spot is where your left timing mark should be. It should end up right in the center of a tooth. This tooth should be 11.5 teeth counter-clockwise to the 1st line you made on the cd and also 86* to it. Mark the cd and carefully mark the cam gear at that tooth.

4. Now you can separate the cd from the cam gear without losing your spot. When your ready to drill the new cog hole in the cam gear, line up the left and right marks on the cd with your new left and right timing marks on your cam gear. Use that same 3/16' drill bit and carefully drill perpendicular to the cam gear surface. 3/16" is smaller than the cam cog so slowly and precisely rotate the drill so that the edges of the new cog hole are angled in. This will allow you to bump the cam gear onto the cam with a rubber mallet yet keep the cam cog snug inside the new hole.

5. Reinstall the cam gear in the new position time it with the other gear and crank. AND, check your ignition timing as a safety measure after you start your car.

When you start her up, she will idle with a "lope" and you should be pulling a bit less vacuum at idle than before. You may have to reset your idle speed as well. Do this before you check your ignition timing. When driving, you should feel enhanced throttle response and note that your turbo spools up much sooner.

And i wasnt talking to you about buying cam gear dumbass. :thumbdown

Why not just be like the rest of us and skip the timing one tooth on the exhaust cam?

Mirage2LTurbo said:

Why not just be like the rest of us and skip the timing one tooth on the exhaust cam?

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becuase that would be so simple. :laugh:
This kid has discovered something he likes let him have fun with it. Even though it looks like it wasted 12 hours of his time. His satisfied with his results. good job dsmer I of never thought of something like tat.

I know this a old thread but I have a few questions about it... I think I have to reset my timing anyway so I think I'll try this out. Which way is retarding the cam??? Would I move the cam gear up or down from center timing notches? And how much would I be retarding it by moving one tooth? Thanks if anyone can help me out.

so what was the protractor for? all you needed to do was make a hole half a thooth farther one way. who cares if your a little off, even with the protractor, my guess is you didnt hit exactly 3.67xxxxx degrees.

Installing a set non-turbo cams gives the same results. Just the opposite direction. The exhaust cam on the non-turbo is advanced five degrees. I did this once only to find the car spooled 6-700rpm slower. The midrange sucked in addition.

Retarding the exhaust cam one tooth gives 7.5 degrees. Idle becomes quite lopey.A little too much in my opinion. A nice little trick would be installing non-turbo exhaust cam in turbo car one tooth retarded. This would give 2.5 degrees retard total. Should idle pretty nice and outperform stock turbo exhaust cam quite nicely.

thanks jerry

tstkl said:

so what was the protractor for? all you needed to do was make a hole half a thooth farther one way. who cares if your a little off, even with the protractor, my guess is you didnt hit exactly 3.67xxxxx degrees.

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I couldn't make the hole half a tooth over as the new hole would overlap the old hole...That would be bad... Think about it. How would It hold up to a race to redline then a sudden lift !!!!

This worked great, was free, and took 30 minutes to do. My spool up on my SMALL 16g was significantly increased. 400-500 rpms.

The 63 engine has quite bit of conservative and emmisions objective in the tune. The cams are degreed for emmisions and not peak performance for their lobe profile. There is a clear and apparent performance increase from this free, quick, and easy to do mod. Kind of like the slut down the street in the land of no regrets ... It worked great. I think out and away from the box at times. I didn't follow the tuning guide. Didn't buy HKS cams. Bought a turbonetics turbo. Defend the EVO3 GT turbo. And generally don't do what most DSMers say do on this forum... I just may put a cut crank in my future stroker set upWTF !!!! My knock was from overrunning my maf and the PO had my timing advanced 15+ degrees . I already new it. I didn't know why the knock went down with the cam degreed like it was...

I was getting slow spool for a small 16g until I ran my first boost leak test... After repairing this, I put the cam straight up and got full spool by 2700 rpms (the small 16g has the 7 cm^2 exhaust housing). Retardig the cam got me full spool at a little over 2100 . It was scarry w/ FWD.

I found that retarding it one hole tooth definately makes it lope too much for it to idle for my set up. Besides I didn't get any more performance from retarding it one tooth or half a tooth. I didn't know about the n/t exhaust cam option. Sounds sweet. But I didn't have a dime to my name not even for a $20 cam. So I bought a $10 twelve pack of beer and enjoyed myself .

BTW. I guarantee you that it was retarded exactly 3.7 degrees. That is, if my protractor is correct.

If this guy is still on this forum. . .

anconover said:

instead of sitting around 1 day retarding your exhaust cam, you should probly figure out why your driving around with 15 counts of knock, and a small16g that isnt hitting full boost untill 3900rpms.

Dont blow 200$ on cam gears so you can retard the exhaust cam a few degrees. Get them so you can degree your cams CORRECTLY.

Click to expand...

Obviously, I thought you were directing the post to me. Since I was the only one discussing those issues.

Showing your rear end in some one's thread is a great way to get your point accross . Before you posted this, I had mention 6 posts back that I already figured out why I had my knock issues. I was only getting 4 counts of knock after fixing this from running out of injector up top. At the time this was the only car I had to get to work to feed my boys and put a roof over their head. I had and have enough self control to stay out of it until I rememdied the problems.

dsm-onster said:

BTW I guarantee you that it was retarded exactly 3.7 degrees.

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not so fast, remember this part of your original post?

dsm-onster said:

I popped off my exhaust cam sprocket this morning, grabbed a good protractor, and measured out timing points so that i could retard the cam 1/2 a tooth (360* / 49 teeth = 7.346...

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I know you enjoy solving puzzles, so here's one for you: How many teeth should the crank sprocket have in order to maintain a 2:1 ratio between cams and crank?

7.346 camshaft degrees / 2 = 3.673 crankshaft degrees



I mean that it was exactly 1/2 camshaft tooth retarded. regardless of my rounding up or not

I'm not worried about the rounding, I was just trying to point out, in a lighthearted way, that cam sprockets can not have an odd number of teeth. The rest of the math works out about the same anyway. :shrug:

pneumo said:

I'm not worried about the rounding, I was just trying to point out, in a lighthearted way, that cam sprockets can not have an odd number of teeth. The rest of the math works out about the same anyway. :shrug:

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Oh, that's cool.

That's right! if a cam sprocket had an odd number of teeth than the corresponding crank sprocket would have a "half tooth". My great granddad has one "half tooth". But, his probably wouldn't hold up to the higher revs necessary for a 4-cylinder !