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Valve springs and head studs necessary?

5K views 46 replies 13 participants last post by  indy2000 
#1 ·
Hi guys. I'm building my first turbo car. My intent is to turbo a bone stock '94 GT minus emissions equipment. I'll be installing a larger in take pump, blow thru MAF and 80lb injectors. I've read and heard that I should run head studs and better valve springs in the E7 heads. I've also read that the heads can still lift with studs and that the stock valve springs are fine. The engine has 53k original miles for reference.
 
#2 ·
IMO, springs are cheap and easy to upgrade. Better to do it now vs when you have too b/c the springs can't hold the extra pressure from boost trying to keep them open.
Remember, if the spring is installed with a seat pressure of 90psi and you run 10psi of boost the spring essentially has 80psi of seat pressure under boost...

ks
 
#3 ·
Hi Kevin. I guess at that point; I might as well purchase cheap aluminum heads. Then comes head studs, rockers, gaskets and larger rocker studs. It never ends. Lol.
 
#4 ·
You can get better springs for the stock cam specs from Alex's Parts for like $150 bucks or less. More is you want to spend more. As for head studs, how much boost will you be running? If the heads are on and don't need to come off, leave it be. If they have to come off for head gaskets later, put them in then. You can install the springs with the heads on the car with the air compressor/spark plug adapter tool.
 
#9 ·
I’ve been down this road before just as your are. You can put studs in without pulling the heads off, drain the coolant and do one at a time then re torque everything. Springs are a good idea but if your using stock cam I’d run it and save my money for now. I’d start at 10 pounds of boost and see how that works out. Let me know if you have any other questions


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#13 ·
I remember now why some say not to use head studs on an untouched stock engine. The concern is the studs altering the bores when tightened. If one were to have the block machined; a torque plate and studs would be used to machine the bores correctly. No? I would assume that Ford has the bores set up for the factory head bolts tightened to spec. Studs have more clamping force but they pull on the block as well as the heads.
Thoughts?
 
#14 ·
What are you doing for engine management? 80lb injectors are way overkill and you will just be hurting your ability to tune at idle. I had 42lb injectors on a gt40p head car with Edelbrock intake and larger throttle body, I was close to maxing them at 10-12 psi but you will be down a fair amount of power from that. Make sure you put in a larger fuel pump than stock as well. 255lph will be fine and is drop in.

I never had an issue with valve springs but lifting the heads was an issue so I'd recommend studs.
 
#16 ·
You might want to do some research on tuning as well as on Deka 80lb injectors. These injectors will not effect tuning in a negative way.
 
#17 ·
Please tell me about your personal experience with Promaxx heads. I'll be glad to tell you about my negative experience with my out of the box AFR 185's.

How did you conclude that tuning hasn't been thought about?
 
#24 · (Edited)
I was under the impression that for every 1lb of boost you lose 4lbs of availble spring pressure regardless if the springs where specd accurately for rates and or total spring travel before bind math was used.( Meaning installed correctly)

That being said the typical generic spring on most street heads end up around 125 130# on the seat 280 to 340 open. 95 percent of the time those types of generic springs work fine on a n.a motor cashed out by 5500 5800 once the user introduces boost it tends to extend usable rpm some and immediately taxes the springs past their limit to keep the valves seated.

You will not hurt a thing running a nice 150# 360# open spring installed as close to bind with in reason,.(060 to .100 to bind would be fine left in the spring for a low rpm turbo motor its good insurance,usable stable power,easier on guides,valve tips,and helps keep the tune up in check so you dont queef head gaskets at the first sign of tire spin,etc etc.

As far as blow through systems,By the the time you buy a meter,electronics or an extender of some sort for the maf,having it tuned,etc etc,you could dang near buy a simple holley system,go back to speed density and have A.I on board protecting the mill.

If you have to stick with an a9l and chip tuning,id be looking at a draw through system,just like running a vortech.That set up still works and isn't really that much more difficult to get right.Meter the air inlet,bypass it back to intake inlet,matching sample tube,housing and injector with an adjustable 1 to 1 regulator gets it done.

Studs for sure,stock gaskets with bigger then needed fire ring dia.from Ford and 12lbs of cram? Nah dont think so.
 
#26 ·
I was under the impression that for every 1lb of boost you lose 4lbs of availble spring pressure regardless if the springs where spec accurately for rates and total spring travel before bind math was used.That being said the typical generic spring on most strert heads end up around 125 130# on the seat 280 to 340 open.95 percent of the time those types of generic springs work fine on a n.a motor cashed out by 5500 5800.Once the user introduces boost it tends to extend usable rpm some and immediately taxes the springs past their limit to keep the valves seated.You will not hurt a thing running a nice 150# 360# open spring installed as close to bind with in reason,.060 to .100 to bind would be fine left in the spring for a low rpm turbo motor.Good insurance,more stable power,easier on guides,valve tips,keeping tune up in check so you dont queef head gaskets at the first sign of tire spin,etc etc.

As far as blow through systems,By the the time you buy a meter,electronics or an extender of some sort for the maf,having it tuned,etc etc,you coule dang near buy a simple holley system,go back ro speed density and have A.I on board protecting the mill.

If you have to stick with an a9l and chip tuning,id be looking at a draw through system,just like running a vortech.That set up still works and isnt really that much more difficult to get right.Meter the air inlet,bypass it back to intake inlet,maching sample tube,house and injector,with an adjustable 1 to 1 regulator gets it done.

Studs for sure,stock gaskets with bigger then needed fire ring dia.from Ford and 12lbs of cram? Nah dont think so.
I have $200 into a nice PMAS blow thru MAF. The stock '94 ECU will do the deed just fine. I'll pay around $400 or less for a proper and safe tune. I looked into the Terminator X system but it's not cut and dry like some think. For instance; you'll have to come up with your own timing table. This Holley setup doesn't do it for you. There is still tuning to be done by the end user no matter what Holley claims. One can hop on the Holley forum and read the many questions users have in regards to their supposed self tuning setup. What's really reassuring is when the dealer can't answer my questions and has to email the rep who refers me to the Holley forum for answers. No thanks. I'll rely on the same ECU that has gotten cars into the 8's. Don't get me wrong; the capabilities of the Terminator X are endless.
Guys are running 12psi and more with their On 3 kits on bone stock engines. Will the gaskets let go eventually? Who knows. I'm going to let the tuner do his magic and rely on him for how much is enough.
 
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#29 ·
I think you need to go back to my original post and read the whole thread. Twin turbo??? Did you not read about the injectors I'm using?
 
#30 ·
I have done the on3 on an 86 fox , also an HP setup on a 94 cobra. so i have some exposure to what you are doing. you will need 60lb inj to make max power, use Siemens . you will need a lot of pump, 340 L min and you may still run out, I use twin 255s, then its -8/-6 lines and new rails. stock cam works well, standard throttle bodys with egr gone works well. Head studs,,I use them, what I found was right when you think the timing is right I would blow the head gaskets,,,so start with timing WAY reduced , like 15degree, get fueling rich under load. start there. Get a GOOD wide band or you will blow it up leaving the driveway. I know
OHH, and then find all the rest of the weak parts, axles ,trans, driveshaft , rear suspension bushings, ect. LOL
I would really recommend an aftermarket ECU, the old ford stuff is obsolete/unreliable and hard to find. remember they only built the ECUs for the 94-95 then went obd2 in 96 and thats another thing.
 
#34 ·
I did some reading about the Terminator X kit. I might as well buy a QuarterHorse and WB and tune it myself. "Self learning" is very deceptive marketing. But hey...you get a nice new harness. ?
 
#35 ·
See no reason to have to do head studs for this setup. Good ARP bolts and Fel Pro 9333 pt1 gaskets is plenty for a stock engine. 80 lbs injectors can be a little of a pain to tune down low...60's do better IMO and will support way more than you'll make with a stock engine. Again...just IMO.
 
#42 ·
I wanted to share one of my combos that I built years ago using the stock ECU and nothing all that expensive or complicated: I ran a stock 302 short block with old school Edelbrock Performer heads and a GT40 intake with a 66 mm turbo. The car ultimately ran 9.92 @ 141, but for the most part it was a fairly reliable mid 10 sec street car that I drove all over the place for over 5 years without much of an issue.

I ran the stock ECU with NO CHIP...no aftermarket tuning system or anything. I ran an MSD 6 BTM box that pulled timing out under boost, I ran 42 lb injectors with a base fuel pressure of about 45 psi, a blow-through MAF, and I ran a 255 lph forced induction in-tank pump...nothing special...all with stock fuel lines and rails. I set my base timing at 15 degrees and pulled 1 degree of timing out per lb of boost. I ran 15 psi on the street and at the track...the car worked awesome!

Sorry for the long post, but I guess my point is...that you can build the caliber of car that you are looking to do with a very basic parts list/tuning strategy that won't drain your bank account and won't "strap" you to a "tuner". Nothing against professional tuners, but I always hated being at the mercy of someone else with my car builds, especially as you make small changes to your combo...ie, bigger throttle body, different exhaust, gear changes, etc. It's nice to not have to pay your tuner every time you make a small change to your car.

I just wanted to share my experiences. Good luck with your build and let me know if I can be of any help.
 
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#44 ·
Yes, stock short block, stock cam with 1.7 pedestal bolt down rockers. The car was very deceiving...looked like a 13 second car, sounded like a 14 second car, but would give crotch rockets a run for their money back in the day! LOL!
 
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