Big Chief Jesel rocker bolts

A search no help so hopefully someone has already solved this problem.

On the 18 degree Big Chief head with Jesel rockers (40 psi boost), the exhaust bolts snape off and of course that then toss's the intake pushrod. Usually an easy fix to get going but this time it damaged lifter on cam side (have not torn down yet).

Tried different bolts including making my own out of grade 8 bolts but problem still raises it's ugly head at an untimely point.

Is there a stud that solves this problem?

Blessings...............Ron Clevenger
Creekside Racing Ministry
Pacific ProComp

 

bolts

For the rocker bolts We use a 12pt head ARP high $$$ bolt. You can get them from nascar teams all day long on ebay cheap. We have hundreds of hits on the set at 420lbs seat pressure and over 40psi.
30-35ft lb torque.
The stand bolt is a special Jesel piece torx head with extra long threads. We have the latest design stand and the heads have timeserts intalled.
After all that, it still bent the stands so I welded it all together with 4130 solid bar connecting stuff.
Aren't Big Chiefs fun???

 

Do Dart Big Chief heads use individual stands for the rockers ?
Or is the intake one stand and the exh a set of little ones ?

I have a set of Sonny's 14 degree Pontiac heads that use a one piece int and exh stand.

Could the Dart Big Chiefs be machined to use the one piece deal ( T&D ) ?
Is this one piece thing a 481X design ?

Seems to me it is a ittle more ridgid that hte little individual stands ?

 

exhaut

You have extream cylinder presssure pushing back on the ex valve, I would check cam timing or maybe worng cam for aplication. Do a comp test and then Retard the cam 2* and do a compression test.

 

Thanks for the reply's............

The 18 degree Big Chief has individual rocker stands for the exhaust and intake.

This is a blown gas deal and only run 9 to 1 CR. I've checked the "compression test" and it's low by blown alcohol standards by design. Harold Brookshire worked with me on the cam design and I've tested others. Don't think it's a cam design problem. Other Big Chief runners (blown alcohol) that I've talked with have the same problem.

I would think that a proper stud application would help instead of a bolt. Anyway that's the direction I'm headed and just seeing if someone has already worked through this and have a part number or ???

Blessings.........Ron Clevenger

 

Like was stated above, I would give the ARP 12 point bolts a try before you do anything too radical. We had several of the stock Jesel bolts break and have had zero problems after getting a used set of the ARP bolts off of Ebay. If I remember right they were a one race NASCAR deal. I talked to ARP about these bolts and they were designed specifically for use with the Jesels. They were big bucks new so we decided to try the used ones, 5 years and lots of passes later we have had zero problems.

Joad Donnelly

 

You can double heli coil the exhaust and put a longer bolt. I bought mine from T&D. Told them what I was doing they knew the bolt for it.
Jesel probably sells the bolts also, T&D was pretty easy to deal with
The Sonnys one piece stand is a world of improvement over the individual stands.

 

"Optional ARP Shaft and Stand Bolts
Manufactured from ARP 2000 material, these bolts can be torqued to 35 ft lbs and are recommended for spring pressures exceeding 800 lbs. open."

This must be the 12 point bolt mentioned.

Thanks for suggestions............Blessings.............Ron Clevenger.

 

studs

Has anyone put studs all the way thru the rocker shaft & rocker stand into the head I believe its 3/8

 

This could help, we ran into this and many more issues with the 18* big chief, first step is to weld the stands together, I used 3/8 stainless bolts cut and then tigged the stands together, Ron Call me if you like and I will share more big chief valvetrain stiff with you

 

Thanks for the replys.

What I have discovered is, when open spring pressure exceeds 800 lbs Jesel recommends changing to the ARP2000 bolts for the rockers. I had never heard this before and I certainly run more than 800 open spring pressure.
I purchased the bolts from ARP and they were very helpful. Already got them in my hands and pretty they are.

One thing is for certain, your never to old to learn new things about drag race engines.

Blessings..........Ron Clevenger
Creekside Racing Ministry
Pacific ProComp