Cylinder heads/ head bolts

[ttaowner]

I have2 other sets of heads that i acquired and i was gonna throw them on a hotair shortblock.what would be the better set to use?part# 25527515 or 25524248. Is there any real diffrence than these than the tta heads besides part# ? I know any of these heads are going to bump the compression slightly!!

What is the part# of a arp head bolt set for the tta? I assume its diffrent than a gn?


Thanks for the help and hopefully i can get my tta's back on the road this year:d

 

[jarredsoon]

these are the part numbers for TTA ARP head BOLTS

HAP 2.400-5 you need 8 units of these
HAP 3.450-5 you need 4 units of these
HAP 4.500-5 you need 4 units of these
200-8509 you need 12 of these, these are washers and you can't use them on bolts that are too close to the exhaust header bolt that goes into the cylinder head.


this is exactly what I have on my car with the 7515 heads

Jarred.

 

[ttaowner]

Between the 2 sets of heads that i have is 1 better than the other?

 

[1BADDAM]

Between the 2 sets of heads that i have is 1 better than the other?

25524248, 25527515, 25536702 (original TTA) heads are the same.

The only difference on a fully assembled factory head would be the valve springs on the 248 & 515 head (certain years) would have a higher seat pressure due to having the roller cam in the FWD 3.8's.

 

[ttaowner]

Thanks guys i really appreciate it. I have a customer who has a machine shop and im gonna trade parts for getting a set or 2 of these redone that way i can get the tta back on the road. They both have been sitting about 5 years while i have been distracted with other projects

 

[dsmith4994]

re:getting your trans ams running

James, Its about time you got those TT/A's running
It only took me 5 years but i finally got mine going again.
You go boy......Dave

 

[Sweet6]

To give you an idea of what the non TTA numbered heads are worth, there is a place in the Northeast that has new NOS bare castings for $100 or so. I paid Champion $100 to buy a set of of 7515 castings from them to port heads for my TTA.

 

[tta983]

What should the original TTA heads with casting #25536702 be worth?

 

[89ICBM]

these are the part numbers for TTA ARP head BOLTS

HAP 2.400-5 you need 8 units of these
HAP 3.450-5 you need 4 units of these
HAP 4.500-5 you need 4 units of these
200-8509 you need 12 of these, these are washers and you can't use them on bolts that are too close to the exhaust header bolt that goes into the cylinder head.


this is exactly what I have on my car with the 7515 heads

Jarred.

Hi Jerred,

I respect your opinion and find you to be right most of the time but, on this one you are a bit off base. It is true that the header bolt washer can get hung on the head bolts but that is easily remedied. Just grind a flat spot on the header washers to clear the 4 head bolts on the bottom. The important washers are the head bolts. I'm not sure what block is being used in this build but, if it's a 109, a 4.1 bore is getting dangerously close to a water jacket. If it's a stage one or stage 2, the head bolt holes are blind and will need a different length head bolt. Just sayin.

 

[ttaowner]

Hi Jerred,

I respect your opinion and find you to be right most of the time but, on this one you are a bit off base. It is true that the header bolt washer can get hung on the head bolts but that is easily remedied. Just grind a flat spot on the header washers to clear the 4 head bolts on the bottom. The important washers are the head bolts. I'm not sure what block is being used in this build but, if it's a 109, a 4.1 bore is getting dangerously close to a water jacket. If it's a stage one or stage 2, the head bolt holes are blind and will need a different length head bolt. Just sayin.

Im gonna use a 1985 gn shortblock that happens to be a 20 bolt pan but is not a 109 block

 

[ttaowner]

Will lt1 / 980 valve springs for gn heads work on tta heads . Flat tappet/ stock cam or are tta valve springs diffrent and if they are diffrent do you guys have a part number. Thanks again

 

[jarredsoon]

Washer grinding

Hi Frank

Yes I agree that grinding the exhaust bolt washers is a good solution to get them to clear the head bolts. I just did this on my new stroker motor as it has cylinder head studs that are pretty high.

I have also left the washers out on some head bolts like suggested and have not had any issue. This is how my other car is and it runs well.

I totally agree that using all washers under the head bolts and grinding the header bolt washers is a better idea, esp on a high perf motor. I dunno why I didn't suggest this esp since I just did this about two weeks before I posted.

Here is a link with some pics of the washer grinding
Stroker motor arrival - Turbo Trans Am Forum

 

[ttaowner]

What about pushrods too? Can i use the gn engine ones?

 

[Quiky One]

Will lt1 / 980 valve springs for gn heads work on tta heads . Flat tappet/ stock cam or are tta valve springs diffrent and if they are diffrent do you guys have a part number. Thanks again

Yes you can. LT1's work.

What about pushrods too? Can i use the gn engine ones?

No, you can't. But someone just had a stock TTA set on here for $30.

Jason

 

[89ICBM]

Hi Frank

Yes I agree that grinding the exhaust bolt washers is a good solution to get them to clear the head bolts. I just did this on my new stroker motor as it has cylinder head studs that are pretty high.


Hey there Jerrod,

I do fall back on my training at times. I have no doubt that the head bolts will work just fine with out the washer. Did you know that in big industry what we are discusing here is actually called a 'fastening system', no BS. In fact, the only time a flat washer is needed is when the hole the bolt is going in is larger than the correct size or some how deformed. I just prefer using the head bolt washers because the are torqed and it's good practice for someone that isn't exactly a mechanical person.
I'm very interested in the studs you are using. Are you using the TTA heads and are you installing them with the heads in the car? I've been throwing this around but I'm not yet convinced they will work in a TTA.

 

[jarredsoon]

studs

I have two buick V6 motors with ARP studs fastening the TTA cylinder heads to the block. These were special ordered from ARP and I do not have part numbers. You might put the heads on with the motor in the car but I would put them on the block with the motor out of the car. Way easier to reach the studs and torque them down. When in the car the ac box gets in the way and stuff. I really like the studs and have had success with them. When I use bolts I leave the motor in the car to change head gasket and it is still a pain to reach the back ones. Also the heads are very heavy to lift over the fender and line up onto the block while leaning over the car.

 

[89ICBM]

I have two buick V6 motors with ARP studs fastening the TTA cylinder heads to the block. These were special ordered from ARP and I do not have part numbers. You might put the heads on with the motor in the car but I would put them on the block with the motor out of the car. Way easier to reach the studs and torque them down. When in the car the ac box gets in the way and stuff. I really like the studs and have had success with them. When I use bolts I leave the motor in the car to change head gasket and it is still a pain to reach the back ones. Also the heads are very heavy to lift over the fender and line up onto the block while leaning over the car.

Thanks Jarrod,

This is pretty much what I suspected.

 

[Jicaju]

I used studs on my TTA. I welded tubes like on a GN on lower holes on header flanges and notch them to clear nuts. Really make no difference if you use bolts or studs once you go over 25-26 psi you will flex TTA heads and you will be pushing compression into your coolant within a period of time. Ask me how I know.

Michael

 

[89ICBM]

I used studs on my TTA. I welded tubes like on a GN on lower holes on header flanges and notch them to clear nuts. Really make no difference if you use bolts or studs once you go over 25-26 psi you will flex TTA heads and you will be pushing compression into your coolant within a period of time. Ask me how I know.

Michael

Hi Michael,

Thank you! I have tried to say this before but got ridiculed. You are spot on.

 

[89ICBM]

What about pushrods too? Can i use the gn engine ones?

Hi ttaowner,

That's hard to say. The tta has independent rocker arms and the gn has shaft mounted rockers so there could be a difference in length, I'm just not sure. Summit did have an adjustable push rod that is actually a mich used to measure the length. If you have a stock cam and rockers just drop the rods in and bolt it up. If you have made a change to the cam you will need to adjust the geometry. John Pearcy used to sell adjustable push rods and I think Summit still sells them. None of this is difficult, especially for you since you are a machinist.