Looking to start my turbo build

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lildemonkid

lildemonkid

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Alright Guys, I'm getting super excited just thinking about this...... :blob:
So, im looking to do a Moderate turbo slant build on my 68. I am looking at a full custom turbo manifold, a GT67 turbo, intercooler, a moderate cam, Aussiespeed intake, bigger valves, re ring and balance the bottom end, some form of tunable electronic ignition, and a t5 out the back side to jam some gears. I'm looking to do a fun street car and maybe some track time. Kinda have a Pro touring vibe. haha. :prayer:

And..... there are some questions to go along with this. :burnout:

How Big of Valves can i run?
Whats the limits on Slant cams?
Where do i find boost friendly head gaskets?
What ring gap are the turbo cars running?
What can i spin the engine to and make good power?
Any suggestions on the T5 swap from an Auto?​
 
You can get ford 300 valves. For a cam, you want something that centerline is about 114° which I haven't been able to find. For ignition, you can run the msd 6BT which allows you to adjust timing retard/lb. of boost. You're going to want to look into a carb with an easy blow through kit.
I literally just took off my turbo setup. I have a Clifford intake, Clifford dual exhaust that comes up to a T3/T4 flange. I have a cheap Chinese turbo on it (just guesstimated the size), and an edelbrock 500 cfm carb in front of the turbo. It's a draw through system. I have pictures on my profile. It pushed about 12 lbs. of boost and got me about 210 horsepower. It could pull along next to a stock small block. I'm considering a twin turbo setup with custom intake and custom exhaust with side draft webers in front of each turbo. Keep me posted on your build. I'd love to see what you come up with.
 
Landons65Dart said:
You can get ford 300 valves. For a cam, you want something that centerline is about 114° which I haven't been able to find. For ignition, you can run the msd 6BT which allows you to adjust timing retard/lb. of boost. You're going to want to look into a carb with an easy blow through kit.
I literally just took off my turbo setup. I have a Clifford intake, Clifford dual exhaust that comes up to a T3/T4 flange. I have a cheap Chinese turbo on it (just guesstimated the size), and an edelbrock 500 cfm carb in front of the turbo. It's a draw through system. I have pictures on my profile. It pushed about 12 lbs. of boost and got me about 210 horsepower. It could pull along next to a stock small block. I'm considering a twin turbo setup with custom intake and custom exhaust with side draft webers in front of each turbo. Keep me posted on your build. I'd love to see what you come up with.
Click to expand...

Thank you Landsons! I'd be really interested in some pictures of that exhaust manifold. I currently have a set of clifford headers on my slant. im just waiting on my aussiespeed intake to come in. i broke my offy intake. I'm looking into a powerjectionIII throttle body EFI for the fuel. just to make it a little more tunable.
 
Man EFI is too expensive for my blood haha. I'll get some pictures of the manifold. I wouldn't do the same thing again though. It took up A LOT of space.

I just talked to Howard's Cams. They offer custom ground cams for /6's! Their phone number is 920-233-5228. Give them a holler and ask a few questions. I told them what I want to do and they ask for the specifics.
 
it is quite expensive but the drive ability and tuning become much greater. i know its going to create some extra weight and take up space. but..... i hope that it'll grab some attention and be fun to drive. i was just checking on crower cams. They offer custom cams for the /6 also. i haven't had a chance to contact them yet though. but i did have a question. i was looking at some of the turbo slant builds. the higher boost cars are using o-ring gaskets on the cylinder. what is the threshold that people start doing this?
 
a lot of people are doing it as a precaution. their tune gets away from them a little bit at higher boost and the head gasket pays. you could go 15psi+ on a solid tune and should not have a problem. it really depends on your tune.
 
no i dont. if you pop over to slantsix.org they should be able to help you out with that. a lot of people are turning impressive numbers with the stock cam.
 
How's this build coming along? I've thought about doing a turbo build....but I think getting a manual swapped in and re-assemble the car first is higher priority....hahaha.
 
QYESTIONS:

1. How Big of Valves can I run?
2. Whats the limits on Slant cams?
3. Where do i find boost friendly head gaskets?
4. What ring gap are the turbo cars running?
5. What can i spin the engine to and make good power?
6. Any suggestions on the T5 swap from an Auto?

1. Most guys run some aftermarket oversize valves that are 1.74" on the intake and 1.5" exhaust. I think you can get them on ebay.

2. A turbo slant six cam that works well is a lot like a stock cam because long duration cams that work well in naturally-aspirated engines defeat the forced induction by having both valves open at the same time (called "overlap) letting the boost out the exhaust port. A good turbo cam would have 210-220 degrees duration at .050" lift with about .484" lift and have 115 degrees of lobe separation. Mine came from Bullet cams

3. Felpro makes a good one that has a "fire ring" design that seems to work well in low boost (up to 15 pounds.) Boost beyond that needs O-rings and a copper gasket, to live... Just my opinion.

4. Ring gap, properly adjusted, runs about .022" on the top ring and .024" on the second.

5. Most good-running turbo slant sixes give up the ghost at 5,500rpm... few run well after that. Do not despair; that is a GOOD thing! It means you don't need a roller cam, or heavy (cam-lobe-killing) $$$ valve springs or $$$ roller rockers. The stock rockers work fine, alomng with some shimmed 340 springs. There are at least two 500 horsepower 225 turbo motors I know of that are red-lined at 5,500 rpm.

6. I believe that turbos LIKE automatic transmissions, for a couple of reasons. The automatic changes gears without having the exhaust interrupted, so the compressor turbine doesn't slow down and have to re-spool, and turbos LIKE to have an uninterrupted load against the engine, which is easier to do with an automatic, like in staging the car for a drag race launch. To demonstrate what makes me think that (like a Fuel motor,) turbo slant sixes really like to be "held back," the guys who have experimented at the drag strip with different final drive ratios, have determined that a turbo slant six will turn in better times with a 2.73:1 ratio than something in the 4's, like a 4.56 or 4.88:1. Strange, but true!

Slant sixes have come from the factory with a variety of clutches, but find a setup that will hold the gobs of torque from a boosted slant six is not easy. It can be done, but the problem is severe enough, and the whole manual transmission setup is difficult enough to make me want to say, "Just bolt a well-built 904 behind it and forget all about shifting for yourself." Your turbocharged engine will thank you!
Just my 2-cents...

Good luck with an exciting project!!!
 
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