Jeep Strokers

Wait.. what does the JP5984 actually fit? Whom did you contact at JP?

Here's the integral message. I don't know more than this :

Hi Patrick

The part number is JP5984 LB10.

Regards Stan

----- Original Message ----- From: "Patrick Durocher" <[email protected]>
To: <[email protected]>
Sent: Wednesday, November 04, 2009 10:09 AM
Subject: Jeep timing set


> Hi,
>
> I bought a JP double roller timing set for my Jeep 4.0 rebuild into a 4.7 stroker. The block has been line bored. I now face a problem as my timing chain has 1/2" deflection. I can't find a line bore kit or chain on your website. Do you make an undersize chain for my engine?
>
> Regards,
>
>
> --
> -Patrick

I'm experiencing all sorts of mess-ups for a few weeks, at work, and with my engine. I had a major mess-up today at work. Looks like I'm not thinking ahead of acting... (FYI I had a car crash 19 months ago and still have some weird things happening in my brain. Had two fractures in my skull....not complaining, just saying). Anywho, my plan is to not degree the cam. I'll be confident about Comp machining, and make doublle sure my timing marks are alingned. Worst thing that could happen is that the cam is crap... But I doubt I have a chance

The timing set is spec'd for a Rover V8, Pontiac and Olds engine. JP didn't have the crank and cam bore on their site, but Rollmaster does and the diameters are different from out engine.

As for degreeing the cam I would highly recommend it. I put my timing set dot to dot and it was off 13*, using the same timing set as you. Three times I removed the set and reinstalled it with the same results. Finally I just moved the cam one tooth and it checked out fine.. dots still lined up.

Ok, some news : I just received my Comp Magnum pushrods : they look awesome!

I'll be degreeing the cam after all. I've started to set up things for that, I'll probably finish by tomorrow evening.

Next weekend, I'll be cutting and welding back a collector for my Pacesetter headers, and making a 2.5" downpipe. I'll try to close the engine, timing cover, oil pan, water pump and install the roller rockers.

Well now, one good news, and one so-so...:

1- I did degree my cam as per Comp intake centerline method, using the dial indicator directly on the pushrod. I did it 2 times, and I came up with 111 degrees, and 110.5. The intake centerline of the 68-232-4 is 110 degrees. That's good enough for me.

2- I installed my rockers today, and my new 9.600" magnum pushrods are still too long.. However, the lifters begin to preload just before the rocker nut is tight. I am at zero lash at approximately 1/8 of a turn or less before the nut is torqued down. Since HS reccomend torquing 1/2 turn past zero lash, I figure I should torque the nuts 3/8 of a turn more. Makes sense??

It does make sense, but throw a dial indicator on the rocker arm and zero it when it hits zero lash. I bet that 1/8" of a turn will equal very little preload.

What I did was install an Allen key perpendicular to a pushrod, using tiewraps, and set my dial indicator on it. I measured 0.006" from zero lash to the rocker nut beeing torqued to 25 lb/ft. I then turned the ajuster nut half a turn. The total preload is 0.028", so I guess I'm good to go. I'll measure it a few more times to be sure.

I checked the preload a few more times on different cylinders and the minimum I got is 0.028', the maximum : 0.044". The 0.044" might be an error though, the average beeing about 0.035" .Torquing the adjuster jam nut gives me around 0.001-0.003" more. Zero lash is harder to find, because of the rocker beeing loose. But I am pretty confident that all the preloads will be within 0.020" - 0.060".

So all rockers are installed, torqued and adjusted. I hate to think I'll have to remove all of them after cam break-in, so I can install my inner valve springs...

That what about I found on mine. That the preload to full torque on the rocker arm is very little. It seems with the Isky cam that I am in between a pushrod size.

Exos wrote: So all rockers are installed, torqued and adjusted. I hate to think I'll have to remove all of them after cam break-in, so I can install my inner valve springs...

Wait.. what? Why do you need two valve springs again? At least all you need to do is unbolt them and not have to set preload again.

The Mopar P5249464 springs are dual springs. Comp says to remove inner springs for break-in.

Are you talking about that flat spring like thing on the inside of the main spring? If so thats a damper and doesn't contribute to the spring force. If you actually have dual springs I would make sure you have the correct springs as I have never seen a MP5249464 spring that was dual. If you do have two springs i would like to see a pic of that.

Ok.. going off of this pic:

You actually removed the damper and it isn't a dual spring. It basically reduces the spring's harmonics by a friction effect. Just put it back now and don't worry about it as it doesn't contribute any force to the spring.

This is what a true dual spring setup looks like:


And this is a comp cam dual spring setup with a damper:

It is a flat spring that goes inside. I thaught that was part of a dual spring...? If you are correct, then what should I do: put those damper back and do the break-in, or put back the stock springs for break-in?

Exos wrote: put those damper back and do the break-in, or put back the stock springs for break-in?

Put them back in. It won't hurt anything. If anythign using a stock spring could cause problems if your cam has high enough lift.

This is taking a lot of my energy... I'd never thaught it would take so long... it's been more than a year now. I like doing it, but it has to come to an end soon. So tomorrow, I'll be removing all rockers in order, then all springs one by one, and put back the damper in each . Then I'll reinstall everything back and I will be at the same point I was, except for the fact that I won't be needing to remove everything again after cam break-in.

I did not take acount of the money it cost me so far, but I can assure you it's way more than a Golen or Titan. I'll be doing this once in my life, with no regrets. It's gonna rock.