1993 Cobra RR's...worth it on stock heads/cam?

Mustang5L5 · Sep 15, 2009

I picked up a set of the Crane Cobra 1.7 RR's. They are the factory ones with the F3 part number on them.

I was planning on doing the install when i did my heads and cam, but part of me wants to toss them on now for the sake of eliminating another box of parts kicking around. I prob won't get to my head/cam install until next summer.

Are there any gains to be had? Or am i better off leaving them in the box for now?

Also, i'm still speed density. Unsure if that will play a role. I'll be converting next year prior to the head/cam install.

Shaolin Crane · Sep 16, 2009

Mustang5L5 said:
I picked up a set of the Crane Cobra 1.7 RR's. They are the factory ones with the F3 part number on them.

I was planning on doing the install when i did my heads and cam, but part of me wants to toss them on now for the sake of eliminating another box of parts kicking around. I prob won't get to my head/cam install until next summer.

Are there any gains to be had? Or am i better off leaving them in the box for now?

Also, i'm still speed density. Unsure if that will play a role. I'll be converting next year prior to the head/cam install.

its not exactly an easy thing to do, i would just wait until you do everything all at once

claytucc3 · Sep 16, 2009

You would see a little bit of a difference. In my opinion, leave them in the box. Do it all at the same time.

v8only · Sep 16, 2009

I went full gt40 explorer motor, ported explorer intake, STOCK HO MUSTANG CAM, 1.7 roller rockers, 65mm t/b and spacer and all the usual bolt ons with speed density with no issues.

While I doubt you'll notice anything huge, if you've got a saturday free, pick up a bunch of beer and go for it. It'll give you the chance to clean everything up and replace all the vacuum lines anyhow while that upper is off.

Mustang5L5 · Sep 16, 2009

Shaolin Crane said:
its not exactly an easy thing to do, i would just wait until you do everything all at once

What's not easy? They aren't adjustable. Just bolt them down and check the pushrods.

I could have the VC's off in less than 20 mins. Not exactly a tough job to do.

If they were adjustable i could see spending some time having to check te adjustment.

Maybe i'll pick up some nice VC's and give myself an excuse.

UPRMike · Sep 16, 2009

I agree with v8only, it's not a bad job at all to swap out rockers. They don't have to be adjusted, and it'll get you familiar with the procedure for setting up the valvetrain. Easiest way to remember the sequence when tightening down the rockers is to think ICE.

In other words,
As you crank the motor over by hand:

Watch the exhaust rocker on the cylinder you've chosen (do them in any order you like) and adjust (tighten) the Intake as the Exhaust begins to Close.

Then on the same cylinder watch the intake rocker and adjust (tighten) the Exhaust rocker as the Intake begins to Open.

I have it shorthanded in magic marker on my engine stand like this:
I
EC

E
IO

lincoln+ford · Sep 16, 2009

even if you crank the motor over by hand and do cylinder say all the odds first then evens it still should only take 10-15mins tops to get the rockers on and torqued.So id say about and hr total.

Inless you just want to get away from the woman or something kill time i wouldnt bother not really going to notice anything.

skunk21 · Sep 16, 2009

If you have time I say do it and yeah it's worth it. you get added lift,effectively making it a slightly larger cam. It should be worth 10-12hp but upgrade your springs. I'm not sure but I think the cobra rockers clear the baffle in the vc but check it to make sure.

v8only · Sep 16, 2009

actually, their are shims for this...it's not just bolt and go.

Their is an entire procedure for this..find 0 lash, then tighten the bolt...any more than a full turn and you need to shim the rockers with the special shim...any less than 1/4 turn and you need shorter pushrods. do not just torque and go, that's how you wind up with noisy rr's

lincoln+ford · Sep 16, 2009

Your not gonna gain that much hp with stock cam and heads.If you had the cam and heads that came on the 93 cobra then yeah but you dont.

Mustang5L5 · Sep 16, 2009

v8only said:
actually, their are shims for this...it's not just bolt and go.

Their is an entire procedure for this..find 0 lash, then tighten the bolt...any more than a full turn and you need to shim the rockers with the special shim...any less than 1/4 turn and you need shorter pushrods. do not just torque and go, that's how you wind up with noisy rr's

Damn, i don't have the shims

Are there 3rd party shims I can purchase and use?

I am starting to think i should just wait. Fall is here and in a few weeks i'll e putting my car away. Prob only 100 more driving miles left really. Don't want to do that and adjust it correctly to find myself yanking it all off in the springtime.

BTW, i'm installing GT-40P's and a TFS-1 cam.

skunk21 · Sep 16, 2009

That's going to be a nice combo, once you get everything converted & a tune she will lay down a nice # and be a hell of a lot of fun on the street. You can get shims from summit racing, amazon, jegs to name a few ford racing has some too part # M6529A302.

I know what you mean the season is coming to a close but 1.7's on a stock motor are still worth it & I still believe with the added lift/duration you would have gained atleast 7-10 ( I'll knock of a few ponies) every motor is different on what it will gain.

Mustang5L5 · Sep 16, 2009

Yeah. my winter project will be gathering up all the minor parts I need like valve springs, head gaskets, head bolts, etc.

As for the exhaust...i'm exploring the possibility of long tubes vs the gt-40p specific headers. Beleive it or not, i'm running the FACTORY H-pipe on my car. I want to get a high flow pipe, but i need to decide now if i want shorty's or long tubes.

lincoln+ford · Sep 16, 2009

youll do just fine with shorties.Im running tfs 1 cam and gt40 heads and explorer intake upper and lower in my lincoln.It moves out really good for being a 2ton car.I can tell if it was in a mustang and geared it would really move out.It just keeps pulling and my aod is shifting at 5k and still have the horrbile 3:27's.

skunk21 · Sep 16, 2009

If I had to do it over again I would have done long tubes but a good set. Facts are facts and you can't beat the gains from a set of tuned long tubes. They aren't horrible to install and alot of people shoot them down because it's pia if you have to do certian repairs but in truth how often do you change out the clutch or smoke a tranny/starter. If it's a well maintained car it just makes sense. I am going to long tubes when I build my next motor JBA's or something along those lines.

v8only · Sep 16, 2009

I yanked the HO cam out for a tfs 1 cam with my gt40p heads. Great combo. I sold the car, then the owner upgraded to a tubular gt40 upper...cosmetic reasons and a 70mm t/b...which I'm not convinced he needed, but he ditched the cats and put 288 at the wheels.

Pedestal rocker arm shim kit $8 FTW
Ford Racing M-6529-A302 - Ford Racing Rocker Arm Pedestal Shim Kits - Overview - SummitRacing.com

1993 Cobra RR's...worth it on stock heads/cam?

Mustang5L5

That is…until I whipped out my Bissell

Shaolin Crane

Banned

claytucc3

New Member

v8only

Active Member

Mustang5L5

That is…until I whipped out my Bissell

UPRMike

New Member

lincoln+ford

Member

skunk21

Active Member

v8only

Active Member

lincoln+ford

Member

Mustang5L5

That is…until I whipped out my Bissell

skunk21

Active Member

Mustang5L5

That is…until I whipped out my Bissell

lincoln+ford

Member

skunk21

Active Member

v8only

Active Member

Similar threads

1993 Cobra RR's...worth it on stock heads/cam?

That is…until I whipped out my Bissell

Banned

New Member

Active Member

That is…until I whipped out my Bissell

New Member

Member

Active Member

Active Member

Member

That is…until I whipped out my Bissell

Active Member

That is…until I whipped out my Bissell

Member

Active Member

Active Member

Similar threads

Privacy & Transparency

Privacy & Transparency