Engine guys please help!

[TIMINATOR]

One of the things we did to get more top end AND mid range, was to use a higher lift, longer duration cam than was normally used for the convertor/ gear combo, and advance the cam 4 or 5 degrees. That allowed higher flow for the top end charge, and we had the earlier intake closing from the advance to help the bottom end.
Then Comp cams came on the scene in about 1976, with tighter lobe centers, faster ramp rates, and higher lifts, and we gave up on "the old ways" and bought Comp cam products.
Although Crane, Isky, and Engle, had a SMALL selection of "good lobes" back then too, most were "old school."
Me and my cam analyzer still keep looking for better lobes, but Comp has the best selection so far. Call and ask them to sell you a "lobe library catalogue."
It only list lobe family groups, but it is thick as others entire catalogue. It has no instructions, but does contain info on intended usage of ramp rates.
I'll dig out some cam cards for a comparison, and post later.
TIMINATOR

 

[TIMINATOR]

COMP CAMS BUICK V-6

FLAT TAPPET 69-248-4 260 H
212/212 degrees @ .050
124 degrees @ .200
.459 lift

Off the shelf roller:
Hyd. RLR 69-300 264HR 10
212/212 degrees @ .050
133 degrees @ .200
.504 lift
Notice nine more degrees @ .050 and.043" more lift.

My custom Hyd RLR
69-000-8
Hyd RLR SPECIAL HR
214/218 degrees @ .050
139/143 @ .050
.584/.589 lift

Duration @ .050 gives defines the basic power band
Longer duration @ .200 gives a wider power band and more HP, especially on the upper end.
More lift gives an even wider power band and more power everywhere.

Notice MY CUSTOM ROLLER over off the shelf roller: only 2 degrees more at .050 but 6 more degrees at .200, with .080" more lift!

All things being equal, you can make more power with less boost with a roller, or even more power with even less boost with a more aggressive roller, and a wider power band. OR JUST MORE POWER EVERYWHERE at the same boost!

But, the same power at less boost means more transient torque, because the turbo spool will take less time to make the same HP.
Also, there will be less exhaust back pressure, less heat, and less possibility of detonation.
OR, just turn up the boost, run alky, and fuggettabbout it!
Different strokes for different folks, and so on, and so on!
TIMINATOR

 

[joed]

Hey guys, Thanks again for all the great information and input here!! I was going to run a little PL data and post if there is anything that might help to see, please post.
I have cam card COMP 206/206 roller (would have gone 212/212 or TIMINATOR special grind if I had known better Next, if there is a quick way to check cam for mis-install before pulling front cover....measure #1 intake peak and crank angle? Is there a tape for the crank balancer that shows degrees? Otherwise I'll just have to take off cover....but then what would I need to verify correct install? What degree advance is correct anyway?

 

[Chuck Leeper]

Hey guys, Thanks again for all the great information and input here!! I was going to run a little PL data and post if there is anything that might help to see, please post.
I have cam card COMP 206/206 roller (would have gone 212/212 or TIMINATOR special grind if I had known better Next, if there is a quick way to check cam for mis-install before pulling front cover....measure #1 intake peak and crank angle? Is there a tape for the crank balancer that shows degrees? Otherwise I'll just have to take off cover....but then what would I need to verify correct install? What degree advance is correct anyway?

Post a legible screen shot of the cam card.

 

[joed]

Post a legible screen shot of the cam card.

 

[TIMINATOR]

As I remember, that Comp roller cam is installed "straight up" with no advance. Pull #1 spark plug, put crank on TDC on OVERLAP, not firing. The balancer will show TDC on overlap too. Both intake and exhaust valves should be open exactly the same amount within .010" or so. If the cam is retarded one tooth the exhaust would be open more, about an eighth of an inch, or more, it will be noticeable. At TDC on the firing stroke both will be closed completely. If you aren't sure what you are doing, mark the balancer with paint and timing tab so it's easier to see. Then bump it around a full turn.
On a single pattern cam with no advance both valves will be open the same amount on crossover. At 4 degrees ADVANCE, the intake LIFTER will be .030 higher. Or measured at the valve, multiply the rocker ratio by .030, for advance calculations. This is the "old guy, quick and dirty" cam degreeing method.
If the cam has 8 degrees longer exhaust duration at .050, but has a 4 degree advance, both lifters will be at the same height on overlap too.
If calculating this at the valve, measure the retainer to head amount for the intake and exhaust and write it down, as it may vary depending on # of valvejobs, valve lengths, etc.
This works with flat tappet cams and roller cams too. Keep in mind lifter bleed down can affect this somewhat, as will seat pressure affecting leak down.
TIMINATOR

 

[Pronto]

I was told that some cams have advance already ground in so installing them at "0" or straight up is actually already advanced. Not sure if that cam is ground like that.

 

[TIMINATOR]

Cams install dot to dot (top gear dot on the bottom, bottom gear dot on top) whether or not they have advance "ground in". On every other revolution both dots are to the top.
Easy way to tell if a cam is ground advanced, (yours isn't), on a single pattern cam like yours, the opening and closing points (numbers) are the same intake to exhaust, but switched opening to closing points.
TIMINATOR

 

[joed]

As I remember, that Comp roller cam is installed "straight up" with no advance. Pull #1 spark plug, put crank on TDC on OVERLAP, not firing. The balancer will show TDC on overlap too. Both intake and exhaust valves should be open exactly the same amount within .010" or so. If the cam is retarded one tooth the exhaust would be open more, about an eighth of an inch, or more, it will be noticeable. At TDC on the firing stroke both will be closed completely. If you aren't sure what you are doing, mark the balancer with paint and timing tab so it's easier to see. Then bump it around a full turn.
On a single pattern cam with no advance both valves will be open the same amount on crossover. At 4 degrees ADVANCE, the intake LIFTER will be .030 higher. Or measured at the valve, multiply the rocker ratio by .030, for advance calculations. This is the "old guy, quick and dirty" cam degreeing method.
If the cam has 8 degrees longer exhaust duration at .050, but has a 4 degree advance, both lifters will be at the same height on overlap too.
If calculating this at the valve, measure the retainer to head amount for the intake and exhaust and write it down, as it may vary depending on # of valvejobs, valve lengths, etc.
This works with flat tappet cams and roller cams too. Keep in mind lifter bleed down can affect this somewhat, as will seat pressure affecting leak down.
TIMINATOR

ok this is terrific and sounds do-able. So I remove driver side valve cover and #1 spark plug. Should I measure using magnetic dial indicator? not sure what best way is. Remove rockers and measure pushrods? or reference off (harlland sharp 1.65) lifters over pushrods?

 

[joed]

Easy way to tell if a cam is ground advanced, (yours isn't)...

The install manual (COMP cams Part #145, revised 5/4/12) has a highlighted paragraph at bottom of page 2 stating "most" High Energy, Magnum and Extreme Energy are ground 4 degrees advanced....you're saying the cam card or spec confirms it doesn't have this feature? Not a big deal either way, just wondering. Thanks

 

[TIMINATOR]

Most flat tappet Comps 292 hyd and smaller are 4 degrees advanced. Same with hyd rlrs. The bigger stuff is straight up.
The 206 and 212 Comp BUICK V-6 hyd rlrs are straight up. Not sure about the 212/218 for the Buick V-6.
Make sure your pushrods are the same length, some builders use different lengths, especially if the exhaust lobes are bigger because the base circle will be smaller, or using different length valve stems . Yours should be the same length. It won't hurt to check.
Measure the lifters or at the pushrods.
DO NOT ADJUST PRELOAD WITH THE
"ADJUSTABLE" rockers, THEY ARE NOT!
They WON'T OIL THE ROCKERS IF THE
"ADJUSTERS" ARE NOT WITHIN A FEW TURNS OF "CENTER"! READ THE INSTRUCTIONS TO MAKE SURE THE BUILDER HAS THEM SET CORRECTLY!
You may need a different length pushrod from what you have!
I don't know who your builder is, so I would check everything just to be sure.
I don't trust anyone,
I check EVERYTHING!
I know about 20 years ago a major company made a run of Mopar small block timing sets with the keyway off 3 TEETH! In their defence, the keyway was located at the 2 o'clock position like a Chevy, not even with the dot, straight up, as a Mopar or Ford would be. This, from a company that only makes timing sets!!!
Call me at 623-877-8553 (LAND LINE) MST 9-6 if you need immediate assistance. I rarely check my e mails or texts.
Good luck! TIMINATOR

 

[hensleyt]

Find TDC compression ,make a 1/2-3/4 turn and stop before your TDC comes around again just slack the Intake adjuster 2 turns or tell the pushrod will just rotate ( like your setting your prelude )and set your dial center of the pushrod hole on the rocker arm. with your finger put just enough pressure on the rocker arm and set dial to 0. Now rotating to TDC dial will start moving, @ .050 on dial STOP and you should just pass TDC -7 like card says.
Side note the Exhaust valve should have just stop moving just before TDC if lifter prelude is correct.
If I have confused you you won't be the first one

 

[joed]

Borrowed the dial indicator today. Hope to be able to do this either Friday or Saturday and see where we are. Will post results…thank you.

 

[joed]

Pull #1 spark plug, put crank on TDC on OVERLAP, not firing. The balancer will show TDC on overlap too. Both intake and exhaust valves should be open exactly the same amount within .010" or so. If the cam is retarded one tooth the exhaust would be open more, about an eighth of an inch, or more, it will be noticeable. At TDC on the firing stroke both will be closed completely. If you aren't sure what you are doing, mark the balancer with paint and timing tab so it's easier to see. Then bump it around a full turn.
On a single pattern cam with no advance both valves will be open the same amount on crossover. At 4 degrees ADVANCE, the intake LIFTER will be .030 higher.

I do not have a good way to mount the dial indicator. I have to rest it and it's difficult to align so the pushrods move freely. OK here is what I was able to get. I rotated the motor around to find the base circle and set zero on the DI. Then rotated to overlap TDC and measured rod lift. Did the same process for #1 intake and exhaust. As i said it was difficult to get the pushrod to move up and down freely while attached to the DI. Anyway I got around .043" lift off base circle on intake and .033" on exhaust. I don't feel really good abou tthe accuracy so I will probably do it again and/or try the other hensleyt method also to see if I can get some agreement.

Will post other results from driving with new plugs.

 

[joed]

Before I took apart for cam test I put in a new set of AC R43TS plugs and ran around 20 minutes with a couple WOT's boost was around 15-16 psi. Still idling chunky and smells rich. #2 looks wet but rest seem ok. I forgot to change the default target AFR on my TT6.1, maybe I should switch to the 5.7. Let me know if any of that would be helpful
.

 

[Mr.Spool]

Those plugs are not uniform

 

[GNVYUS 1]

In case I missed a few things..
You're chasing a lot here, simply get a way to read the Air Fuel Ratio and post back at these ranges.....

Scanmaster basic readings at idle like
TPS
IAC

Then...
Idle 850rpm AFR?
Cruise 1800-2000rpm AFR?
WOT AFR (10.0?)

Maybe you need a simple injector pulse width tune and you're done. You've gone through a bunch and it all seems legit so far, good work.

Except, plug 2, looks wetter than the others, possible sticky injector etc.

 

[Pronto]

If the first build ran fine except for the dirt in the bearings issue, I doubt it's tune or something like that. I think it's time to pull it out and carefully inspect it.

 

[joed]

In case I missed a few things..
You're chasing a lot here, simply get a way to read the Air Fuel Ratio and post back at these ranges.....

Scanmaster basic readings at idle like
TPS
IAC

Then...
Idle 850rpm AFR?
Cruise 1800-2000rpm AFR?
WOT AFR (10.0?)

Maybe you need a simple injector pulse width tune and you're done. You've gone through a bunch and it all seems legit so far, good work.

Except, plug 2, looks wetter than the others, possible sticky injector etc.

I can post my data page from Powerlogger. I guess we're discussing 2 things but I was hoping they are related. I turned alky off and boost down but I don't have a non-alky chip so if I was going to get into the tune, I'd need to clean some of those items up.

 

[joed]

If the first build ran fine except for the dirt in the bearings issue, I doubt it's tune or something like that. I think it's time to pull it out and carefully inspect it.

Yes, thank you. It ran really nice right off the start with chip default last time, crisp, clean idle, easy start, no smoke, just that stupid knocking! I keep trying to think of anything that could be different ....but should be exactly the same as before. However compression is borderline and leakdown is good...so that's why I'm questioning cam timing. I have the dial indicator for one more day so I'll just try to get one more data point. Just can't think of what else it could be, but I'm no expert at all. I'll be ticked if I pull the cover and it's fine;\ LOL