Degree specs when using adjustable cam gears-TIII

[turbovanman²]

I have found nothing here, anyone have them then I can also put them in an FAQ. Just bought some adjustable cam gears for the van,

[86Shelby]

All 4 valves for cylinder #1 should be closed at TDCc. Close enough?


Ok, here's the figures I had stored away, not sure if they are the stock ones though.
Intake: 121 ATDC
Exhaust: 104 BTDC

[turbovanman²]

Thanks, I think,

I know there posted on TD but I don't go there anymore.

[iTurbo]

All 4 valves for cylinder #1 should be closed at TDCc. Close enough?


Ok, here's the figures I had stored away, not sure if they are the stock ones though.
Intake: 121 ATDC
Exhaust: 104 BTDC

Yep, those are the stock centerlines. You will be glad you got the adjustable gears because my stock gears were WAY off!

[turbovanman²]

Yep, those are the stock centerlines. You will be glad you got the adjustable gears because my stock gears were WAY off!

Cindy gave me a deal on some red ones she had kicking around. Perfect for my red themed engine bay,

So those numbers are with the crank at TDC?

[iTurbo]

Not sure what you mean, but the crank will be at 121' ATDC with the intake valves at max lift and the crank is at 104' BTDC with the exhaust valves at max lift. Man I need some coffee.

[turbovanman²]

Not sure what you mean, but the crank will be at 121' ATDC with the intake valves at max lift and the crank is at 104' BTDC with the exhaust valves at max lift. Man I need some coffee.

Ok, gotcha. Now I need some coffee,

[iTurbo]

Keep in mind that max lift occurs over a number of degrees on the wheel, so you'll need to read the degree wheel before/after max lift and divide by two to get the true centerline. For example, I read the degree wheel at .020" before/after max lift and then double check using .030 and .040 before/after max lift just to be sure my readings are consistent. Hope this makes sense! Once you do it and visualize the process yourself with everything in front of you it really is pretty easy. For me, the most difficult part was setting up the degree wheel and dial indicator correctly.

[turbovanman²]

Thanks, I have read about it but never done it personally. This will be my first time actually doing it.

[turbovanman²]

Man, this is hard to do, engine is so hard to turn over,


Ok, done. Intake took along time just to be sure but exhaust took 5 mins, I cheated. Intake is out 2 deg, ex 3 deg or 1 line and 1.5 lines.

I did the intake then put it at TDC, I checked the alignment hole at the intake sprocket, it was bang on, drill bit slid thru. Checked the exhaust, off. So aligned it then checked it, bang on, opens at 104 deg.

[Xtrempickup]

sounds like fun I think I will have to prepare to put my stage 1 cams in and the gears, but I dont think I can do the centerlining without help and i have to see if my friend has the dial indicator

[turbovanman²]

I am soooooo glad I did it on an engine stand.


BTW, after removing the timing belt to fix my sticky cam, the factory marks aren't bang on, the intake is off a little bit but the exhaust, you can slide a drill bit thru easily.

[iTurbo]

Ya doing it on an engine stand would be a lot easier. It's not so bad doing it in the car (or van in your case) but it's a little tougher to read the wheel and turning over the engine about a million times gets old real quick!

I checked the centerlines when I initially got my Spirit R/T running with the stock cam gears. IIRC, the exhaust was sitting at 99' BTDC and intake was at 124' ATDC, so both were retarded. I don't think it was off a tooth either, because if it was, it would have been way more off than that. I'm now using the centerlines LWP suggested for my stage I cams (108'/118').

[Turbo3Iroc]

BTW, after removing the timing belt to fix my sticky cam, the factory marks aren't bang on, the intake is off a little bit but the exhaust, you can slide a drill bit thru easily.

Simon, this is why you degree the sprockets. The cams or sprockets aren't off, the belt is. You could re-tension that same belt and come up with totally different numbers. This is why it's useless to use the cam offset keys.

Kelly

[turbovanman²]

Simon, this is why you degree the sprockets. The cams or sprockets aren't off, the belt is. You could re-tension that same belt and come up with totally different numbers. This is why it's useless to use the cam offset keys.

Kelly

Well I rechecked it after I put the belt back on and they were still in spec. Interesting about the belt theory though.

[Directconnection]

Re-check it after breaking it in and I would guess it will give slightly different readings due to belt stretch.

[iTurbo]

That is one reason the sprockets are so nice. You don't have to mess with the belt tension at all. I also would not be surprised to see the centerlines change a little as the belt gets some miles on it.

[MOPAR2YA]

Before I got the adj gears, I chassed my tail for 2 days trying offset keys...And the belt tension will throw the cams out.

BTW. iTurbo, did you get your issues figured out?

[iTurbo]

BTW. iTurbo, did you get your issues figured out?

Hello Wallace, to answer your question: yes and no. On the one hand the car has been VERY reliable, probably the most reliable TM I have ever owned yet. I have most every issue worked out but some things are still mysterious. I haven't been able to get more than ~12 in/hg vacuum at idle, and the power band doesn't start until about 3000 RPM. From 3k RPM to redline the car hauls! Below 3k RPM the car is very sluggish and throttle response is a little wierd. It is difficult to take off from a red light without lugging the engine or riding the clutch or major fanfare. For in town driving, it can be a bear. Add to the fact that I have a 3.50 final drive ratio so that makes it a little worse in that respect as well. And did I mention I live at ~4500ft elevation!

So it very well could be that nothing is wrong and it is simply the combination of parts that I put into the car; mostly between the cams (shifting power upwards) and the lower final drive (making it a bit tougher stay in the power band around town). It has taken some getting used to for sure. It is a very different kind of 'fast' than my other cars. The torque curve feels a lot different but the R/T pulls hard to redline and can really stretch it's legs. I have to admit I'm surprised no one else with the LWP stage I cams says anything about adverse driveability or low RPM performance. Some times I think something else might be wrong but I just can't find it...the car is just lazy down low and that is all there is to it. Modify driving accordingly

I probably would experiment with it more but have been busy with my TIII SL project. That car is going to be 2.5L mostly because of my experience with the Spirit R/T so far.

[turbovanman²]

Before I got the adj gears, I chassed my tail for 2 days trying offset keys...And the belt tension will throw the cams out.

BTW. iTurbo, did you get your issues figured out?

I couldn't even imagine using offset keys, that would take hours,

Jeremy, maybe take it to a dyno and play with advancing the intake and exhaust cams or ???? to see if you can lower the powerband or just tweak it 2 degs one cam at a time and see what happens?