Slant 6 turbo motor advice...

[bill dedman]

This probably doesn't belong in this forum, but I can't think of anyone else to ask that would have more reliable information, so here are my questions:

Building a bracket motor for an early A Body MoPar to be used running in a car that will hopefully weigh about 2400 piounds PLUS driver

A '63 Valiant can be built at this weight, I think; gutted interior, 'glass hood, front bumper, and lots of weight-saving measures, elsewhere.

The engine will be an early model 225 c.i.d.slant 6 with most of the money being spent on a forged, stock-stroke crank, some really good rods (need info here), high-quality, forged pistons, with a reverse-deflector design @ 8:1 compression ratio, and a ported head with "big" (LOL!) valves (what a laugh!!!).

One area of this build that I have NO experience with, is the size of turbo to select

It will be a blow-through 750 Holley setup, with an air-to-air intercooler, and will run on alcohol.

I'd like to take advantage of the nearly-indestructable slant-6 block and reciprocating asssembly, and turn this thing about 7,000 rpm and utilize 20+ pounds of boost.

A sort of an inline Buick GN.

Reliability is a key issue, of course, but these engines (particularly, the early ones) are reputed to withstand a LOT of "abuse" (boost and RPM), even with their 5 main bearings and 4.125" stroke.

A "worked" 904 will deliver the power to an 8.8" Ford rear end, likely.

What I need advice on is, whether to consider the later model head that did away with the sparkplug tubes, and how much these early engines can be bored.

Also, what size turbo would work with an engine with these parameters.


I'll be researching these questions elesewhere, but I respect the opinions of the posters on this forum more than anyone else's.

Thanks for any information. Lookin' for about 600 HP at the flywheel.... Is that unreasonable?

[Billy Nees]

Bill, send me a PM.

[Chris "drooze" Wertman]

Not if its done right,

I have a friend who built and is rebuilding just such an animal Dart though, same vintage.

BIG fan.....BIG fan sequential injection BIG intercooler.....hes the guy to talk to , he may even have the stuff you need.

He too has a "Build Blog" on all the items he did to the car and what works , what dosent and what youll run into.....other than the very real possibility of turning your motor into itty bitty chunks of metal, but hey.....thats the fun part right.

http://madscientistmatt.blogspot.com...ost-index.html

This was from the "original" build before it went intercooled turbo....just the EFI system he built from scratch for it. Nice guy, sharp, sharp tech.

Cheers

Chris

Originally Posted by bill dedman

This probably doesn't belong in this forum, but I can't think of anyone else to ask that would have more reliable information, so here are my questions:

Building a bracket motor for an early A Body MoPar to be used running in a car that will hopefully weigh about 2400 piounds PLUS driver

A '63 Valiant can be built at this weight, I think; gutted interior, 'glass hood, front bumper, and lots of weight-saving measures, elsewhere.

The engine will be an early model 225 c.i.d.slant 6 with most of the money being spent on a forged, stock-stroke crank, some really good rods (need info here), high-quality, forged pistons, with a reverse-deflector design @ 8:1 compression ratio, and a ported head with "big" (LOL!) valves (what a laugh!!!).

One area of this build that I have NO experience with, is the size of turbo to select

It will be a blow-through 750 Holley setup, with an air-to-air intercooler, and will run on alcohol.

I'd like to take advantage of the nearly-indestructable slant-6 block and reciprocating asssembly, and turn this thing about 7,000 rpm and utilize 20+ pounds of boost.

A sort of an inline Buick GN.

Reliability is a key issue, of course, but these engines (particularly, the early ones) are reputed to withstand a LOT of "abuse" (boost and RPM), even with their 5 main bearings and 4.125" stroke.

A "worked" 904 will deliver the power to an 8.8" Ford rear end, likely.

What I need advice on is, whether to consider the later model head that did away with the sparkplug tubes, and how much these early engines can be bored.

Also, what size turbo would work with an engine with these parameters.


I'll be researching these questions elesewhere, but I respect the opinions of the posters on this forum more than anyone else's.

Thanks for any information. Lookin' for about 600 HP at the flywheel.... Is that unreasonable?

[Phillip marvetz]

check out www.slantsix.org lots of turbo slant six info there

[mtkawboy]

Heres some advise for you, run it with an automatic. The blocks may be bulletproof but the cranks arent. Back in 1970 I ran a built Hyper pak motor in a 51 Anglia in H/G with a T-10 4 speed behind it with 4.86 gears. I broke 3 cranks leaving the line @ 6000 right at the rear flange where the flywheel bolts on. The motor would still run even, just wouldnt move. As for the 7000 rpm, forget that unless you want to find out how tough the motors really are. Bulletproof stock, yes, heavily modified not so much despite old wives tales. Just trying to help here, spare me the stories about how tough & fast your buddies is. Mine ran 12.1s 40 years ago, not fast now but not bad then considering the tires available.

[art leong]

Can I suggest a simpler/cheaper way of going about building your Valiant?
First go buy a boat. Then take the slant six and use it for a mooring anchor. LOL
Just Kidding
But seriously take a 2.4 liter motor from a SRT4 ot a GT Cruiser turn it sideways. Bolt a 904 trans to it and have fun. With a relatively small amount of money you can make 650 horsepower. And drive it on the street.
The parts are readily available, and not one of's.

[Chris "drooze" Wertman]

Thats a Great Suggestion Art

If you want something REALLY strange get a 6 Cylinder Hemi 6 Pak motor.....hard to get your hands on but theyre out there.

That one of my "Dream Cars" one of the Valliants with the 6 Cyl Hemi 6 Pak......Unfortunatley the last one I saw sold for almost 100k.....

But that was an RT and all original.

Originally Posted by art leong

Can I suggest a simpler/cheaper way of going about building your Valiant?
First go buy a boat. Then take the slant six and use it for a mooring anchor. LOL
Just Kidding
But seriously take a 2.4 liter motor from a SRT4 ot a GT Cruiser turn it sideways. Bolt a 904 trans to it and have fun. With a relatively small amount of money you can make 650 horsepower. And drive it on the street.
The parts are readily available, and not one of's.

[art leong]

SRT4 motors are easy to get. With bolts ons you can make over 500 hp. With pistons and rods you can go over 800. With NO2, Wild boost, and Methanol you can get up around 1300.
Not bad for an American made 4 cylinder.

[Mopar Steve]

Here's a couple links to look into:

http://gassermadness.com/visitorscars/drake/index.htm

http://www.theturboforums.com/smf/in...c=50672.0;wap2

[bill dedman]

Wow! WOW!!!!

Thanks a LOT for all that great information!!! I certainly didn't expect such a bountiful response to my questions. I want to thank everybody who responded, and I'm going to investigate all suggestions, because they ALL made lots of sense!!!

My partner in this, has several MoPar "toys," and I have a blown, V8 bracket car, myself, but we both wanted a new project, and it looks like it might happen. But, with all this new information, now, I'm not sure just what direction it will take. We'd never considered anything but a /6, and had initialy just thought of bolting a Buick GN "take-off" turbo onto a fairly stock 225 slant 6 and going from there... but, those 4-bangers make that idea look pretty lame.

FWIW, I have raced a potpourri of drag cars since 1956, and have never had one with a manual transmission, so a 904 was the first thing we agreed upon.

Now, I'm wondering how to go about bolting a 904 to an SRT-4 motor.

My partner in this venture is 72, and I am, 71, and neither of us has the faintest idea of what is involved in the details of dealing with EFI. My first reaction would be to remove the injection and go with something I do have a limited amount of experience with, a blow-thru carb setup of one kind or another, but my common sense tells me that that could be the dumbest thing I could do, so don't worry; that won't happen.

Before I waste any more of your time, he and I have to investigate the cost factor involved in there two possibilities. I'm on a "fixed" income, and it's not "fixed" very well...

We initially decided to make this a low-budget, junkyard-parts, experience, since we both already have bracket cars that we work on, constantly.... it was just going to be a low- budget exercise to give us some experience in turbocharging (some of my best frriends own Grand Nationals!!!)

But, now, that may be changing, with all this new information.

I want to thank you all again for the good info and advice! I KNEW this was the place for quality opinions and info I just couldn't get, elsewhere!! You guys didn't disappoint me!!!

I'll get back to you!