66 twin turbo mustang coupe

[twinturbo66]

Hello All,As you can see from my signature I have a 66 mustang coupewith a fuel injected 347 stroker motor. It has twin T3/T4 turbo’s and the power is put down through a Lentec AODwith a manual valve body. I have an 8.8rear axle but it has a worn out diff and only 28 spline axles.
Here is the issue, My car keeps blowing head gaskets. Nowthis last time I’m not 100% sure that it was a blown head gasket but I’m maybe90% sure. I haven’t broken down themotor yet to see.


1) The first time the car blew a head gasket I hadn’tcompletely upgraded the cooling system to what it is now so I thought that itoverheating maybe caused the head gasket to blow… When my mechanic broke downthe motor he realized that the original guy that put it together used the wronghead gaskets, didn’t have stuff torqued to spec and he didn’t have the AFRheads machined for the ringlock head gaskets. I figured all those contributed to it so we fixed it and put it backtogether. Also resolved the overheatingby installing a Ron Davis radiator with a nice shroud and twin electric fans,Mezeire electric water pump and a custom Turbonetics Air to Airintercooler. We also added a transcooler and an oil cooler to help keep all my fluid temps down.


2) So the car was tuned and was putting down around450whp and 440tq through the AOD. I knowwith even a low estimate on drivetrain loss that it had over 500hp at the crankwhich could have contributed to the motor giving up or whatever happened.


I’m currently deployed and I’m trying to decide which optionand where to go from here. I figure thebelow are my best options. With any ofthese I would more than likely have to get a IFS front suspension to remove myshock towers for better clearance and air flow. I would also have to throw in about 1k towardsstrengthening my Lentech and another 1500 for the rearend to give me new axlesand a new diff.


1) Get a nice 347 Cubic inch (331 stroke with thelarger bore giving me 347) DART block with forged internals and throw on some larger flowing AFR heads, larger injectors andturn up the boost.


2) Get rid of the turbos and simply thow in a nicenew Coyote motor with a six speed auto out of a new 5.0.




3) Grab a Junkyard LS motor for $600 bucks and turnup the boost until I blow it and after that spend another $600. Pretty cheap. Iwould get instantly banned from this site and shunned anytime someone asks meto open up the hood.
__________________
1966 Mustang Coupe- late model 347 FI Stroker motor 9:1:1(I believe), twin T3/T4 Hybrids, Lentech AOD w/manual valvebody. SN95 Front suspension with 4 wheel Cobra Disc brakes using hydraboost. 8.8inch rear end, 28 spline axles/3.55 gears and worn out diff. 450hp/440tq @10lbs of boost

[jckinthebox]

4) 200ci turbo straight 6? would solve some clearance issues and would probably be the first ever!

[bs46488]

I'd say you are at a pivotal cross road with the car. My guess would be too much boost, but 10lbs isn't a whole lot. What's your end goal?

I'd vote for the Coyote, but the costs are going to start to add up. $1k for tranny, $1.5k for rear end, $1.5k for IFS (plus labor and paint?), $7k for engine?, $1.5k for ECU, wiring, fuel upgrades. That's almost $13k.

[a6d9cmro]

go with the LS.

[Nothingface5384]

RCS ifs kit for front, TCI torque arm for back
have you tried an MLS headgasket for the 347?
Coyote would be sweet buy way to pricey
What about a 351C with AL heads and a S470

[bryant]

hey Jason, good to see you here.
if you go the ls rout then you need to go with a different transmission also. most likely a 4l80. so dont forget to factor that in.

[fordsbyjay]

You have something amiss because you should be making a lot more power than that at 10 pounds of boost I would think. You are blowing head gaskets because of excess cylinder pressure so either too much boost or too much compression. . Do you have any type of data logger to see what the boost is exactly as the gasket lets go. The boost starts low and ramps up so it could be spiking and you just not seeing it.

[twinturbo66]

hey Jason, good to see you here.
if you go the ls rout then you need to go with a different transmission also. most likely a 4l80. so dont forget to factor that in.

Hey Brant, The LS route was more of a striking out because of frustration and as a joke. Yes, it would be cheap but in reality I can't go out like that with a Chevy in a Ford.

[twinturbo66]

Fordsbyjay, The CR on the engine is around 9:1. It has T3/T4 turbos on it now, I'm not sure exactly which versions or the housing or AR. The car was tuned using a MegaSquart ECU and it's using an pneumatic electronic boost controller controlled by the MegaSquart.

[Ant]

What about a 351c with LS heads

[Munssey]

I guess the component we're missing is what you want the car to do (or I just skipped over it ;) )

If money is no object and you've got the shop to handle it, my vote is Aluminator w a 6 speed and never look back. Quickest route would be a 331 (347s have a lot of heat issues for my blood) and all the go-fast parts you can.

Either way, IFS for sure!

Sounds like she is going to be a nice ride either way you go.

[twinturbo66]

I guess the component we're missing is what you want the car to do (or I just skipped over it ;) )

If money is no object and you've got the shop to handle it, my vote is Aluminator w a 6 speed and never look back. Quickest route would be a 331 (347s have a lot of heat issues for my blood) and all the go-fast parts you can.

Either way, IFS for sure!

Sounds like she is going to be a nice ride either way you go.

A DART 331 might be the easiest since I already have everything else for the most part however if I'm already going to get a DART block I may as well go for a 351w based 427! Get the IFS to ditch the shock towers and allow for more space, Find out exactly what size T3/T4 turbos I have and ensure that my turbo system is up to the task. Someone was also saying that I should ensure that I have a "rising" FPR so that for every pound of boost that my fuel pressure is increasing. I know my late model 5.0 upper manifold is pretty restrictive so I could ditch that for a victor one.

IFS front, upgrade my transmission and upgrade my 8.8 rear with some stronger axles, new gears and diff.

[lucky13firebird]

Dart 427 all the way bro, you already got the small block trans...

[lucky13firebird]

Oh and just snag an explorer 8.8 and shorten one axle... 31 spline axles, posi, 373 gears... average 150 bucks or so

[capri v8 driver]

Dart 427 all the way bro, you already got the small block trans...

I went the 427 route and I don't regret it yet.

[lucky13firebird]

Yup, and if money is tight, a 408 stroker long block for under 4k and it's still 500hp or so and vry streetable....

[twinturbo66]

I finally got back from deployment and got around to finding out exactly what size turbos I have on the car.
They are Precision Turbos: PTB505-5857 5857SP TURBO W/BILLET COM WH

So on the site they DO NOT have the 5857SP but they DO have the PTB505-5858 which can handle 620hp and has the following info:
Compressor wheel: 2.285" (58.0mm) Ind/3.00" (76.2mm) Exd
Turbine Wheel: 2.555" (64.9mm) Ind/2.280" (57.91mm) Exd

[Justin@EntropyRad]

How are the gaskets blowing? Between cylinders, or out the side? Are you sure they are blowing, and not lifting under boost? You have a boost gauge showing how much at full spool, or perhaps spiking well above??

TFS Box-R is a good SBF boostable intake

[Z06killinSBF]

I just want to see pictures of the set up!