Comp Cams Cam and Valve Clarity

[Grinder]

I having been reading about the Comp Cams. On here I have read that you can not use the Comp Cams springs as they are designed for the 4.2L. When I look at this kit online it shows that it will fit the 4.0L, is this just a typo as it does not really fit?

I am gathering all of the information I can before I start to order my parts. All of these parts are going to go into a 99 XJ Cherokee.

I have acquired a 97 4.0L complete.
I am not sure if I should us the 4 or 12 cw 4.2L crank I believe I have both here.
Comp Cams 68-231-4 Cam
Comp Cams 822-12 Lifters
Comp Cams 3219 Timing Set

Comp Cams also sells all of these parts in a complete kit K68-231-4.

Question is will Comp Cams 926-12 valve spring set fit my block? I am confused with reading that they will or wont fit. I know the seat pressure is extremely high but it seems that if Comp Cams sells a kit with these included they would be the right springs? Is any one running these valve springs? Does any one see any problems with this combination so far? I know that most people recommend the MP P5249464 valve springs but it seems as though there are some issues with the valves using these springs, or do I just need to but new valves along with springs? Any input would be greatly appreciated.

[dwg86]

The 258 used a 3/8 valve stem with a 7 degree lock. The 4.0 uses an 8mm valve stem with an 8 degree lock. So the valve spring retainers that fit the springs that come in the comp cam kit are for a 3/8 valve stem with a 7 degree lock and will not fit the 4.0 valves. You can't use the stock 4.0 valve spring retainers on the comp springs because the 4.0 retainers are too small in diameter. Unless comp finally came up with a reatiner that will fit the 4.0 valves and the comp springs.

I am running the Mopar springs without any problems.

[SilverXJ]

Comp Cam's kit won't work. They know this as they have been told this by several people. Their response was to grind a a cam with lower lift for the factory valve springs instead of actually making a correct kit. I suggest you look in the FAQ section under Misc for lafrad's spring setup fro beehive springs if you don't want to go with the Mopar Performance units. I also suggest you look at other cam manufactures as comp cams does not care to correctly support us.

[Grinder]

Thanks for the answers guys. dwg86 did you use the factory valves in your motor? or how can I tell if my motor uses the correct valves? Also if I put the KB 944 pistons into my motor do I need to deck the block? It seems to me if i deck the block my compression would go up and not allow me to run pump gas.

[SIXPAK]

The 4.0 uses an 8mm valve stem with an 8 degree lock.

FWIW, the factory locks are 7 degree not 8 degree. I was on a big hunt last year to find some Titainium retainers and sent a set to several places. After inspection at ISKY Cams they verified that the factory locks are indeed 7 degree.

[lafrad]

When it comes down to it, the difference between 7 and 8 * is not something i would concern myself with, personally.

Now, the difference between 7/8* and 10*... definitely.

[SIXPAK]

When it comes down to it, the difference between 7 and 8 * is not something i would concern myself with, personally.

Now, the difference between 7/8* and 10*... definitely.

It was just a clarification of facts. Many swap back and forth without issue. But, if you were spinning 7000 and had 200 seat and 500 open you opinion may change.

[Grinder]

SIXPAK, What springs are you running with your ISKY cam?

[dwg86]

The 4.0 uses an 8mm valve stem with an 8 degree lock.

FWIW, the factory locks are 7 degree not 8 degree. I was on a big hunt last year to find some Titainium retainers and sent a set to several places. After inspection at ISKY Cams they verified that the factory locks are indeed 7 degree.

If you look at the desciption for the retainer it says 8mm. http://www.summitracing.com/parts/DCC-4452032/. About half way down this page is the description for the locks to use on the Mopar retainers. http://www.bpemopar.com/22L25LENGINES.htm There is a part number for a 1 groove and 3 groove, that also shows 8 degree. I have never measured them, just paasing along Mopar specs as they are written.

[dwg86]

Thanks for the answers guys. dwg86 did you use the factory valves in your motor? or how can I tell if my motor uses the correct valves? Also if I put the KB 944 pistons into my motor do I need to deck the block? It seems to me if i deck the block my compression would go up and not allow me to run pump gas.

No, I used SBC 11/32 undercut stainless valves. My valves and guides were worn. It was cheaper to buy new stainless SBC valves, and hone the guides to size for the 11/32 valves. I used a Comp 10 degree retainer that fit the Mopar Performance valve springs. Going with the 11/32 valves, I could have used a number of different valve springs and retainers, but I had already bought the MP springs, and I liked the specs. The SBC valves, retainers, and 10 degree locks are pretty heavy.
I am going to build another stoker for a project jeep. This time I am going to use LS1 2.00/1.55 valves. The ls1 valves are lighter than the small block chevy.

[SIXPAK]

SIXPAK, What springs are you running with your ISKY cam?

Not running an ISKY cam. But the springs I use are PAC-1201.

[kptuck]

When it comes down to it, the difference between 7 and 8 * is not something i would concern myself with, personally.

Now, the difference between 7/8* and 10*... definitely.

This thread is what has me questioning if running 1998 Jeep 4.0 8 degree locks on GM beehive springs and 7 degree retainers will cause issues.

Thanks!!