The dreaded "While your in there syndrome"

NY65912 · 06-27-2006, 06:45 AM

While my lil' 80 SC was in the shop for 930 brakes, IROC body mods and full Elephant suspension upgrades I nonchalantly asked for a valve adjustment. Upon removal of one of the valve covers a broken headstud was found.

Sooo......now the question of do I have only the headstuds replaced or do a few little engine mods to bump things up a bit.

After much agonizing and thought this is what myself, my son and of course my wrench (Bill Rudtner - Rutdner's Racing) came up withbased on the 3.0

993 headstuds
ARP rod bolts on stock rods (for now)
10.5 to 1 JE pistons
Street port and polish heads - "a little massage"

The above will work in conjunction with 46mm PMOs, SSI's, Monty exhaust and/or M&K mini straight "mufflers" when allowed. MSD will fire the plugs, until the next phase of cams and dual plugs. Probably go to 3.2 in the future as well.

Any guesstimates as to hp numbers? Does this plan sound ok?

I have tried as hard as I could to control myself......thanks for reeling me in Jr.

I'll be reporting back periodically.

Cheers

Jeremy Cottrell · 06-27-2006, 07:25 AM

Yeah, while you're in there, you might as well go ahead with all of that.

Sounds like about 230HP on the brain dyno to me.

kenikh · 09:05 AM

Can you really expect to run 10.5:1 on single plugs without sending your motor to the grave early? BTW, SINCE YOU'RE IN THERE and replacing pistons and using carbs, you need bigger cams. DC44s come come to mind...

Yeah, I understand the "while you are in there" syndrome. I was going to simply reinstall the MFI on my early car. After some inspection, we realized the car's heads were not original (no MFI spigots) and the cams didn't have MFI drive.

So, I bought NOS '69S heads and John Dougherty cams (much hotter than stock) to make up for those issues. But since I'm in there I am now heading toward a complete rebuild (even though the motor is strong) to install my GT3 oil pump; but since the case will be open, why not install Pauter rods, have a full balance done, install oil squirters and shuffle pins, add a high end valve train, rebore the MFI stack and do a twin plug conversion so I can add 906 pistons?

How the HELL did that happen?

Clay Perrine · 06-27-2006, 09:33 AM

In the 914 world this is called "Dirk Wright's Disease".

Dirk Wright was a 914 owner who drove his 914 every day. Dirk had squeaky plastic bushings in his 914 pedal box. He took the pedal box out to replace the bushings. He sees rust under the pedal box, so he thinks "while I am in there I should fix the rust"....

This kept going until he had completely disassembled his car.

True Story.

I don't know if he ever got it put back together.

I got a somewhat severe case of it when I did my 914/6. But I actually got my car back up and running.

BTW.. there is no known cure for Dirk Wright's Disease.

kenikh · 06-27-2006, 09:37 AM

Quote:

Originally posted by Clay Perrine
BTW.. there is no known cure for Dirk Wright's Disease.

BANKRUPTCY?!?

jtratza · 06-27-2006, 09:52 AM

Definately John Daugherty cams. I got his 964 grind profile for my cams last year during the rebuild. Very pleased with the cams and John's excellent service.

Purkinjefibre · 06-27-2006, 12:01 PM

I agree with Kenik- 10.5:1 is probably too much for street gas and single plug on an SC. 9.5 would work safely.

I am using Supertec headstuds, give Henry @ Supertec a call. His studs are amazing...

304065 · 06-27-2006, 12:12 PM

Mike,

Thinking about it, if you are going to the trouble to change the pistons AND converting to PMOs from the CIS, you might as well go to the trouble of changing the cams. The SC CIS cams are deliberately mild to avoid inducing back pressure waves in the CIS system that will move the airflow plate around too much. With the PMOs, you can use a bumpier cam that can generate all kinds of interesting reversion pulses up the carbs. Also, the longer overlap period of a more aggressive cam will mitigate the effect of the higher compression pistons.

The cam towers are already off for the stud replacement so it's no more work while you are in there.

Check out http://drcamshafts.com for the basic specifications. Something like the DC-40, an improvement on the early S profile, would be a nice compliment to your 3-liter motor. Or to really get your blood pumping, why not the 3.0 RSR cam? You already have four-bearing towers. . .

kenikh · 06-27-2006, 12:15 PM

John can make any cam with 4 bearings. Let your insanity be your guide!

Bobboloo · Bobboloo's Garage

As others have said cams. Mod-S or wilder.

10.5:1 is alright if you don't mind buying race gas but keep in mind that means no long trips unless you want to carry extra race gas with you.

The 3.0 rod bolts are supposed to be very robust. I believe your weaker link from an over-rev is the valve springs. I'd save the money on the rod bolts and put it toward stronger springs.

I would talk to John Dougherty before you port the heads. The cam decision should be the determining factor for your ports.

Jeremy Cottrell · 06-27-2006, 01:17 PM

Dirk Wright Disease, strangely sounds like Do It Right Disease. We should all suffer from this.

fintstone · fintstone's Garage

Quote:

Originally posted by Purkinjefibre
I agree with Kenik- 10.5:1 is probably too much for street gas and single plug on an SC. 9.5 would work safely.

I am using Supertec headstuds, give Henry @ Supertec a call. His studs are amazing...

I agree. I would stay at 9.5:1 unless doing the dual plugs now or using only racing gas.

I also recommend Supertec headstuds.

RoninLB · 06-27-2006, 07:23 PM

hey Mike

you're smog test free.

install a cam with some overlap and run the right compression ratio for 91 octane. Tyson is a big fan of the Mod-S cam.

Gas continues to get worse.

Install a Racor fuel filter for around 75-100$.

as long as you're flipping cyls & pistons go with more cid.

I wouldn't use JE on a high mileage street engine.

is this car at Rudtner's now? When is the next time you're going there?

JP911 · JP911's Garage

You will probably need to have your distributor recurved for more advance with the 46mm PMOs.

RoninLB · 06-27-2006, 07:47 PM

Quote:

Originally posted by JP911
You will probably need to have your distributor recurved for more advance with the 46mm PMOs.

I installed a new RS/Euro 2.7 Carrera dizzy that has a steep beginning curve for around $300. PP sells them if you supply the part number for them.

NY65912 · 06-28-2006, 03:15 AM

Ron, a Racor filter/seperator was installed along with a recurved dizzy by the PO when he did the PMO install.
I will probably (hopefully) get down to the shop Fri late PM.
I am getting a little concerned with the CR as well.
I will inquire about GE 40 cams and springs as well.

Thanks for the imput fellas, keep those cards and letters coming in.

Cheers

RoninLB · 06-28-2006, 04:18 AM

Quote:

Originally posted by NY65912
when he did the PMO install.

I will probably (hopefully) get down to the shop Fri late PM.

keep those cards and letters coming in.

off topic but what cc are the carb venturis ?

36 should be max for track w/6.4-6.8k rpm cams according to text formula.