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Any chance anyone knows the opening/closing I/E degrees for the L67 cam? Anyone ever degree it?

Thanks!

Normally Aspirated Camshafts

Description Duration @ .050" Lobe Lift L.S.A. Centerline

Stock L36/L26: 182/192 .258/.258 N/A N/A

Power Adder Camshafts

Description Duration @ .050" Lobe Lift L.S.A. Centerline

Stock L67/L32: 182/192 .258/.258 115 N/A
 

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Any chance anyone knows the opening/closing I/E degrees for the L67 cam? Anyone ever degree it?

Thanks!
This is straight out of the GM Holden workshop manual for the L67 / L36 engine. The same engine as yours basically.

Camshaft lobe lift
Inlet .........6.56mm (0.258")
Exhaust .....6.48mm (0.255")

Valve timing
Inlet
Opens - BTC............29.5 degrees
Closes - ABC............115 degrees
Duration..................324.5 degrees

Exhaust
Opens - BBC.............76.5 degrees
Closes - ATC.............78.5 degrees
Duration....................335 degrees




Cheers

Deek
 

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Thanks!

This is straight out of the GM Holden workshop manual for the L67 / L36 engine. The same engine as yours basically.

Camshaft lobe lift
Inlet .........6.56mm (0.258")
Exhaust .....6.48mm (0.255")

Valve timing
Inlet
Opens - BTC............29.5 degrees
Closes - ABC............115 degrees
Duration..................324.5 degrees

Exhaust
Opens - BBC.............76.5 degrees
Closes - ATC.............78.5 degrees
Duration....................335 degrees




Cheers

Deek
 

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abbott racing heads cams

ARH Naturally Aspirated cam
-210/220 @ .050
-.320" lobe lift on the intake, .512 with a 1.6 rocker ratio
-.320 lobe lift on the exhaust, .512 with a 1.6 rocker ratio
-112 lobe separation

ARH Turbo/Blower cam
-220/220 @ .050
-.320" lobe lift on the intake, .512" with a 1.6 rocker ratio
-.320" lobe lift on the intake, .512" with a 1.6 rocker ratio
-114 lobe separation
 

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L67 cam vs L36

I had read some where else that the stock (Series II) L67 cam had slightly more lift and duration than the stock L36.

You list them as the same, which is correct? Are there different L67 cams on the Series II
 

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Trying to get my head wrapped around these #'s. Are you SURE they are correct? I mean, this is telling me that the stock L67 cam is 324.5 degrees GROSS duration? But yet only 182/190 @ 0.050? That is one screwed up cam....

I found this

And this makes much more sense to me. but I don't know the gross duration to calculate the intake/exhaust opening/closing event degrees.



This is straight out of the GM Holden workshop manual for the L67 / L36 engine. The same engine as yours basically.

Camshaft lobe lift
Inlet .........6.56mm (0.258")
Exhaust .....6.48mm (0.255")

Valve timing
Inlet
Opens - BTC............29.5 degrees
Closes - ABC............115 degrees
Duration..................324.5 degrees

Exhaust
Opens - BBC.............76.5 degrees
Closes - ATC.............78.5 degrees
Duration....................335 degrees




Cheers

Deek
 

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hay guys whats this one?
 

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I had read some where else that the stock (Series II) L67 cam had slightly more lift and duration than the stock L36.

You list them as the same, which is correct? Are there different L67 cams on the Series II
The L67 & L36 cams are the same cam, no difference in the camshafts.

BUT

There is a 5° advance difference in the L67 & L36 camshaft gear keyway positioning.

I recently did an Inlet only degreeing of the stock camshaft in a L67 & then fitted the L36 camshaft gear & did it again.

The results were:

@ 0.050" using the L67 camshaft gear -
Inlet opened @ 22.5° After Top Dead Centre
Inlet closed @ 27.0° After Bottom Dead Centre
Inlet centre line was @ 114°

@ 0.050" using the L36 camshaft gear -
Inlet opened @ 27.5° After Top Dead Centre
Inlet closed @ 32° After Bottom Dead Centre
Inlet centre line was @ 119°

If you add up the opening & closing you get 184.5°

Which is very close to the 182° we have seen posted for the L67 & L36 cam specs.

Cheers

Deek
 

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I just picked up a PRJ LL cam.....


Duration @ .050" 214º/220º
Intake Lift .305" (1.6 Rockers .488, 1.8 Rockers .549)
Exhaust Lift .285" (1.6 Rockers .456, 1.8 Rockers .513)
ICA: 113°
LSA: 114°
 

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Should be fine to use. Just note cam gear used will affect the installed position. I think the stock 3800 cam and the L67 cam are the same, but the installed position is advanced on the L67. Swapping to a stock L67 cam gear will move cam I think 5 degrees advanced, which will move power curve LOWER about 600 rpm. So it would make the car feel better off the line but might trade off some power at high rpm (usually not a problem, low end torque is more enjoyable than high rpm torque....)

Being this has its own timing set, it should be whatever is advertised, but if you use a stock GM set, note the differences between the L36 cam gear and L67.
 

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Small base circle camshafts

One of the posts mentioned "reground small base circle camshafts". It is possible for a reground camshaft to have a smaller base circle.....and related parts. However, there are new small base circle camshafts with small base circles. These are more often used in "stroker engines". I these cases, the longer crankshaft stroke puts the rods too close the lower portion of the cams and in some cases BIG TIME FAILURES will happen. Hence, cam companies make small base circle cams specficly for engines with longer than stock stroke crankshafts.......

Many moons ago when we were young, we used to buy reground cams for our street hot rods. In reality, these cams didn't hold up very long and also were not done as well as a camshaft new cam.

A little tid-bit from yester year........... Jake
 

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I never ran one but I have heard of Pontiac's breaking lifter bores from too small a base circle on a solid lifter using Chevy lifters.... bad news....

One of the posts mentioned "reground small base circle camshafts". It is possible for a reground camshaft to have a smaller base circle.....and related parts. However, there are new small base circle camshafts with small base circles. These are more often used in "stroker engines". I these cases, the longer crankshaft stroke puts the rods too close the lower portion of the cams and in some cases BIG TIME FAILURES will happen. Hence, cam companies make small base circle cams specficly for engines with longer than stock stroke crankshafts.......

Many moons ago when we were young, we used to buy reground cams for our street hot rods. In reality, these cams didn't hold up very long and also were not done as well as a camshaft new cam.

A little tid-bit from yester year........... Jake
 
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