Approximate hours to change rockers

[MST0118]

I intend to change out the rockers in my engine so wanted to get a sense of how long it would take if I have an experienced shop do it. The engine is currently in the car but needs to come out anyways for other work (it's a 2.8 engine based on a 7r mag case). Any rough idea on time to complete this job? Thanks.

[mreid]

Two hours including a valve adjustment. The key here is the engine is out of the car.

[jpnovak]

And are you also changing cams such that the rocker surface and cam lobe match? That ads to the total time.

[DRACO A5OG]

Are you swapping for new? geez that is going to be pricey.

I would send to DRC and have them rebushed, honed and resurfaced, eta 2-3 weeks.

2-3 hours max if no issues. Make sure they properly torque the rockers shafts to 21ft lbs or you will have a leak sooner or later even with RSR seals.

[MST0118]

Yes, I have new DC80 cams from John and I recently had a set of early forged rockers rechromed by Mike Reed at electronic chome and grind and having them rebushed as well. My engine is freshly built with zero hours on it, so just want to change out the existing rockers. Thanks for the tip on the 21 lbs. I currently have the rsr seals installed and hoping for no leaks.

[boyt911sc]

These are the rockers I sent out for rebushing to Craig Garrett (aka CGarr) and got them back after only a few days. The rockers arrived on Friday at his shop and were shipped out to me on Monday.





What is most surprising was that I don't know him and have only heard good feed about his work. I have already installed the rockers in the engine and have yet to make payment. The quality of his craftmanship is so amazing that I am pulling out all the rockers in the other newly completed rebuilt motor to be sent to him for rebushing.

Someone in the Engine Rebuilding forum had said it was a "no brainer" to use Craig's services. I was skeptical and reacted unfavorably. Thinking the guy must be a buddy of Craig (?). And my recent experience with Craig Garrett's work is beyond my expectation. Craig is very good in what he does. My regular local machine shop for the past 20 years is doing satisfactory job for me but not as good as this guy Craig. So it is really a "no brainer" and switching service.

Tony

[MST0118]

Tony, thanks for posting that and I agree with what you say. Ironically, I was in communication with Craig earlier today and I'm also using him to rebush my rockers.

[boyt911sc]

Originally Posted by MST0118

Yes, I have new DC80 cams from John and I recently had a set of early forged rockers rechromed by Mike Reed at electronic chome and grind and having them rebushed as well. My engine is freshly built with zero hours on it, so just want to change out the existing rockers. Thanks for the tip on the 21 lbs. I currently have the rsr seals installed and hoping for no leaks.

MST,

The rocker shaft bolts are M6. Double check the suggested torque value of 21 ft-lb. for the M6 rocker shaft bolts to prevent shearing them. Refer to torque specification in Appendix A (Wayne Dempsey's 911 Engine Rebuilding Book).

Tony

[DRACO A5OG]

For what it's worth: "Competition Engineering - CE's war on oil leaks"

I was nervous as heck doing this but now I am enjoying leak free rocker shafts and no need for RSR seals on upper shafts.

[jpnovak]

Craig Garr does great work. And not just on rockers...

yes, install rocker shafts dry and then pump lube through the splash hole when finished. I use a trigger operated oil gun for this.

[boyt911sc]

Originally Posted by DRACO A5OG

For what it's worth: "Competition Engineering - CE's war on oil leaks"

I was nervous as heck doing this but now I am enjoying leak free rocker shafts and no need for RSR seals on upper shafts.

Jim,

You can not just apply extra torque to a fastener at your whims. There are certain guide line how much a specific size fasteener is torque. For example, a M6 fastener:

Grade 10.9 is rated at 11 ft.lb.
Grade 12.9 is rated at 13 ft.lb.

So applying an excessive torque of 21 ft.lb for a M6 faster is not prudent. You could do what makes you happy but by giving a recommendation to others is something different. Sorry I have to disagree with you. We are just discussing technical subject. I personally like you.

Tony

[DRACO A5OG]

Oh no worries Brother Tony,

I am just posting my own experiences, I also did not want to go to 21 ft lbs, but sure enough it leaked, then I went to 18 ft lbs and it still leaked, It stopped once I went to 21ft lbs.

The theory is the used cam housing shaft mounting holes stretch and the called spec torque was initially for brand new assembly with virgin cam housings.

I do concur, if OP has any doubts, do not do it. But one should check everytime one adjusts their valves or one will go thru this:

You Must CHECK the Rocker Shaft Bolts when you DIY Valve Adjust!.

I have personally helped many Pelicans with rebuilt engines where the shafts have moved. Yes, it is possible the engine re-builder made a mistake in alignment but very doubtful unless all the Pelicans I helped had their motors rebuilt at MotorMeister re-build it, LOL But seriously, OP do not do it unless you are 100% confident.

[DRACO A5OG]

edit: 20 ft lbs ( 20.24 ft lbs or 27.45 Nm )

[brighton911]

Craig did my heads and rockers. Fantastic quality of work and very reasonable pricing!

[KTL]

Craig is a fantastic guy. I've personally known him (in person, at home and at the track) for over ten years now. He's the kinda guy you'd like to be your neighbor and hang out with on a regular basis, he's that good of a guy.

Aside from the personal bias? He does fantastic work reconditioning rocker arms, cylinder heads, cam housings, sleeving engine case main webs (his version of shuffle-pinning) and other little tricks he's developed. Very talented, very fair guy.

Regarding the rocker shaft hardware, the thread size is actually M7, not M6. So they can be torqued a little higher than M6 typically would allow