sounds exactly like a good project to try to learn some welding skills then before doing all the patch panels i'll have to do.
Build Thread The Hoopty Chronicles - New House, New garage, New Car?
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Well, after installing the new pump and plug wires, then bumping the timing to 14°, it's a whole new animal. Instead of bogging when I hit 2nd at WOT, it lights the tires up and spins half way through the gear (mind you I have some nice 275 street tires out back). I haven't dumped the codes yet, still need to do that to verify the computer is happy. I know I am!
Also finished porting the heads on Saturday. The gist of the port work:
Intake :
- Flattened the radius on the left wall as you look at the intake side
- knocked down the valve guide
- opened throat a little
- widened the short turn radius at the floor
- laid the short turn radius back some
- blended the rough edges in the bowl
Exhaust:
- knocked down EGR bump
- laid back the short turn radius
- knocked down valve guide some
Also did some light polishing in the chambers and smoothed the transition from the seat area into the chamber. I didn't touch the roof of the ports and especially stayed away from the floors. Up next will be a trip to the machine shop for new seats and a valve job. The only question I don't have an answer for is how much to mill the heads. Just enough to ensure a level deck, take it down .030", or somewhere in between..... Input?
Also finished porting the heads on Saturday. The gist of the port work:
Intake :
- Flattened the radius on the left wall as you look at the intake side
- knocked down the valve guide
- opened throat a little
- widened the short turn radius at the floor
- laid the short turn radius back some
- blended the rough edges in the bowl
Exhaust:
- knocked down EGR bump
- laid back the short turn radius
- knocked down valve guide some
Also did some light polishing in the chambers and smoothed the transition from the seat area into the chamber. I didn't touch the roof of the ports and especially stayed away from the floors. Up next will be a trip to the machine shop for new seats and a valve job. The only question I don't have an answer for is how much to mill the heads. Just enough to ensure a level deck, take it down .030", or somewhere in between..... Input?
Do not mill the heads past a resurface to level the deck. As you lower the head, you mis-align the ports and bolt holes. Granted, it'll be small, and the intake boltholes have enough slop to deal w/ a .015 misalignment, but the roof, and floor of your ports will be off.
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Dammit man,.....you should know I'm gonna look at something I said and edit it several times before I leave it alone.
( just look at the difference between the one you quoted, and the final version)
Give me a minute!
In reality,. .030 isn't a deal breaker. You can still modify everything (if it even needs it at all) to fit/match the newly lowered head.
That turbo 86 had meth as fuel, and didn't have enough compression for the engine builder (at 12:1) so he milled the hell out of My R heads. Bolt holes had to be hogged, and the intake had to be milled so it would sit lower.
Well, I was hesitant to mill them anyway as I'm still debating whether or not I want to add psi in some manner later on when funds permit. May be a moot point.
I have to admit, I'll be crushed if these heads don't flow worth a damn. I spent a long time researching what to do and about a solid month's worth of time working on them between the head I ruined and starting the new one.
The onlt bolt holes that will go funky on a head resurface will be the intake bolts since they're at a 45. If the engineer and machinist who made the intake did there job right, there should be 1/32 (.03125) bolt clearance in those holes, and milling .012-.015 off the heads should only move thise intake bolts either the same or root of that (too early to do the math right now).
Fwiw, I had .015-.018 taken off my tfs heads and you would have never known.
Either way, probably best to have the same amount taken off the deck as the valve seats so that that relationship doesn't change.
Fwiw, I had .015-.018 taken off my tfs heads and you would have never known.
Either way, probably best to have the same amount taken off the deck as the valve seats so that that relationship doesn't change.
Alright, it was bugging me so i did the math:
.015 off the deck moves the intaje holes in .0106
.015 off the deck moves the intaje holes in .0106
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Hey dude if it doesn't fit, I'll measure the holes and clearance them for you. It's not a big deal. That windsor i ran in my 79 had .060 milled off those heads and i port matched it. It was a monster.
Edit: two words. Prussian blue.
.030 is very common with gt40's from what I've seen(I have never used them so no personal experience). I think these heads are going to perform well for you. Are you going to port the lower intake? This also should clear up any port alignment issues and obviously help.
The lower appeared to have been port matched. It was like $200 to get the lower ported by Tmoss. I'd like to get it done, but want to get the heads flowed first to make sure it's needed. If the heads won't outflow the intake as it sits, then there is no point, right??
After you get the heads done and get some flow numbers, have you decided what direction you want to go with for a cam? Just a fwiw I read yesterday on the corral where a member did the same build and busted out 310 rwhp-and around 320 rwtq. That's tfs head numbers! I do believe he went with a custom but not sure. With bumping compression up near 10:1 will let you get more creative. Even though 40's have been done 1000's of times I still love these types of builds. Very curious to see what your numbers are(flow and final dyno-if you do dyno it).
Sorry. I'm computer illiterate and don't know how on my phone. It was in 5.0/5.8 tech. If you go over there it probably can't be more than a few pages back.
It's on the first page. Op name is "Spawn" and the heading is gt40p dyno graph or something of that effect.
I read that thread. He used an N41 cam, but those heads looked really good! I think he claimed that he bought them already done off someone else, and his machinist said they were the best done iron heads he had ever saw.
Joe
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