Hello every one, I have a 1973 Plymouth Scamp that looks like it’s got a 426 under the hood but in reality it has a slant six. I know the capabilities of a slant six but I don’t know how to achieve them. Can some tell me how to get the maximum street performance out of my slant? I do not plan on drag racing its just a street car. I love this car and I am not going to just toss aside my great slant six and drop in a V8. I know that Offy makes a 4-barrel intake and Clifford has the Hyper Pak. which do you recommend? Also I want to put headers on for dual exhaust. Is Clifford the only one that makes slant six headers? What carb do you recommend for each of the intakes? I want a carb that has an easy linkage hook up. But if the hard linkage hook up will get me a lot more power I will do the extra work. Last is a new camshaft required after the slant has been modified? $$ isn’t really a factor in this build so please give me any suggestions. Thanks for your help!

Others know more about how to actually achieve performance out of a slant than I do, but since I happened to see your post I'd suggest that you add a little bit more information.

Its true with any engine that as you increase its absolute performance, you tend to decrease its "manners." It will idle more roughly, consume more fuel, be more difficult to drive in cold weather (or ANY weather if you get carried away), and (if you go far enough) break more often. How much comfort are you willing to give up for added performance?

_________________

My slant six is an original 1973 225 ci. My car is an automatic; it has the standard 1-barrel carb and intake. The head is recently rebuilt and the rest of the motor is very solid. When I build up the engine I don’t mind the rough idle, I live in Florida so cold weather isn’t really a factor, even in winter I can go out in shorts. Fuel economy is not really a big deal but I don’t really want a drastic decline from its current burn rate.

If I had the chance, this is what I'd do for me.

I'd convert to electronic fuel injection and have a turbo setup built.

I don't think many people will argue that this is one of the big ways to get from ho-hum to zoom-zoom, but it's also one of the most expensive. Just about all the parts need to be custom made for a slant six, but the stock engine and cam should respond very well to the increased airflow.

Done correctly, a turbo efi slant six would be streetable.

I've also seen a guy with a supercharger fitted on a slant (in pictures). That looks like a riot as well.

_________________
1980 Aspen 225 super six

Hey Slant6Ram about how much do you think that last setup you posted would cost? I dont think that is what I am looking for but it sounds interesting. I dont really want a turbo setup just more horse power but not drag power.

Probably the easiset route is to put on a super six intake and a header. If you go with a 4 barrel, you need to do some internal work to the engine or else you're wasting your money. Don't forget about changing the rear end.

I disagree. I put an Offy, 390 Holley, and Clifford headers on a stock Volare motor in my '66. With a 3000 stall and 3.91 gears it was faster than a lot of "built" Slants. It was also faster than some V-8 cars at the track. It ran 16:20's@80.

_________________
Official Cookie and Mater Tormentor.

Turbos can be VERY streetable, but it takes a bit of fabrication and tinkering.
When you get the right turbo for your use, they are just like a stock engine, until you get on it...

You've come to the right place to get the advice you are seeking!

There's some real experts here (I'm not of them, however).

BUT - I can tell you about my set up.

I have the Offy 2x1 (two one barrel carbs) manifold, with two Carter BBSs. I've got a semi-mild cam, and some head work.

I also have the Clifford 6x2 headers, and a couple of Flowmasters.

I think I'm running 3.23's in the back.

I haven't run the quarter yet - but I should be able to get 17s.

My set up is very streetable.

A lot of folks like the Offy 4bbl manifold as well.

The problem with a more radical cam and an automatic is "stall speed" - that is, you won't be able to rev your engine high enough to get into the powerband at the line. So if you get a lumpy cam, you'd probably want to get a high stall converter.

Even with my light 63 Dart, and mild cam, I could use more stall speed.

As an interesting exercise, get an inexpensive tachometer (if you don't already have one), and drive around for a few days. You'll see that you rarely go over 3,000 RPM.

I like the idea of total bolt-ons - headers, manifold, carb, ignition. Then if it's not fast enough - you can always slip a cam in, and mill the head.

_________________
1963 Dodge Dart, motor by Doug Dutra, Offenhauser two carb intake, Pertronix, Clifford 6x2, Flowmaster 40's, Erson RV15/295 RDP, head work. Addco anti-sway bar, urethane suspension bushings, KYB's, racing leafs, SSBC discs. Need ZDDP? Get STP.

Turbo is not drag power. It's a way to get more power out of less cubic inches of displacement. Turbos are used in many high end street cars because they work and have excellent results.

I don't really think that the turbo is the very expensive part, although a good setup (for daily use) would be expensive and require some careful fabrication.

The hard/expensive part is the EFI, which is critical to really making the turbo streetable and practical. Again, it's all custom fabrication because there were no factory EFI slant sixes and no one is offering complete aftermarket kits designed for slant sixes.

Do a search on this site for Megasquirt, which looks like a very promising solution, but requires a great deal of determination and study to build. (I'd love to have one some day.)

Another EFI solution that I've looked at is Holley's Projection system for Jeep inline six engines. While this is expensive and not as good a solution for even fuel distribution (in theory at least). It does look like it would mostly bolt into place and then require a lesser degree of fabrication and tuning to make it work (compared to mega squirt). This is what I understand to be a throttle body injection system.

Once you finish an efi, you install the turbo and then spend a million hours trying to tune it all to work right, but once it does (if ever) it will be one kicking slant six.

I'm not even at an amature level when it comes to these topics. I don't suggest that a turbo efi slant six is a good idea for most people to try and build. If money is no object, then go for it. Otherwise, build a high compression, ported, carburated motor and be safe knowing that there is lots of experience behind what results you will get.

If I had to guess at price, I'd say have $5000 ready, but more or less depending on who does all the work.

_________________
1980 Aspen 225 super six

Turbos add a lot of ummm....not high rpm torque, so you don´t have to break your tach to get big power...
They run on the load on the engine, and will probably go faster with less gear (to a point)

I read about a guy back in the 60's who put a turbo on a slant (i think that was the only thing) and was able to do a quarter mile in 9 seconds........

Kinda going back to the original question...

do you wanna be a li'l bit more faster, willing to eat some rice, or you wanna empty the crap out of your bank account trying to get a racing slant to work on the streets?

even more important: how reliable and dependable do you like/need your cars?

I'd say, if you wanna "wake up the beast", I'd go with a comp 252 cam, offy dual 1 barrel intake, 2 holleys 1920 (as even as you can get them) and dual headers or dutra duals. Dutra duals is the way to go to avoid excessive fab issues, and/or unnecessary complications. They keey your heat riser so if you live in cold areas your mileage wouldn't be so hurted... anyways if you're going for performance and you'll be stpping on the gass all day long expect nothing less but a 318ish mileage. Don't clog your PCV, go bigger valvles and some porting (speed porting as I recall from dough explanations) sivalvles.com have oversized slant six valvles in stock, a complete set in-ex is like 130 bux (I got a quote 2 months ago) shave your head 1.5 mm and deck your block another .5 mm and use some thin but strong head gasket. And recurve your distributor so your mill see 15 BTDC initial advance 28- tops 30 BTDC mech plus a 8.5r vac pod unit. You'll need to do some kickdown fab if you have a 904, you can go lokar, big time saver.

I think that you would love this setup, it will give her more power and you ain't gonna end up banging your head against the steering wheel anytime you need to dial anything in or loosing some teeth when idling.

another thing to look at is rear end ratio. I'd go with a 3.23 suregrip

That's my 2 cents. EFI and Turbos are neat, but I'm starting to believe that for a daily driver, we need to wait some more time till someone comes up with a bolt on (or something more close to a bolt on) equipment. Not to say they can't be used, though.

_________________
Juan Ignacio Caino

Please use e-mail button istead of PM'ing. I do log in sometimes but I'll be answering quicker thru e-mail.

Turbo is not drag power thats interesting . Last year At Bristol Tenn Tom Drake went the fastest time down a drag strip any Slant door slamer car has ever done. 9.83 can some one come up with any better combination.
We will see Thanks Ron Parker









Hell Hath No Wrath Than A Possum Scorned

Turbos are perfectly streetable. The Auto manufacturers would not be putting them on new cars if they were headaches.

Every engine that has been in the simca would be a perfect street motor. No wild cams(MP cam), no high comp(8.5-1), stock rods(used both 198 and 225), off the shelf pistons(hypereutectic 2.2 turbo pistons). Heck the first motor had stock cast pistons and ran 6.50' on 13-14# of boost. Had over 250 runs on it and never gave us any problems. The only thing we do that would not translate to the street is methanol BUT converting any of these motors to gas would not be difficult and probably a little cheaper because of small injectors.

The biggest expense would be fabricating a plenum and exhaust manifold. Megasquirt like Lou madsen runs would be a good choice and work well. Even the Holley stuff would work well. The motor itself is a pussycat compared to the motors in some of the other fast cars...but put the boost to it and look out. I believe you could take any one of the two motors we have run and put a street car in the bottom of the 7's(1/8) without much effort. Heck we would even be willing to help someone with the tune-up if they show up at the races just to have another turbo car out there.

Turbos add an incredible amount of torque(what you want in a street car anyway) as well as increase the hp nicely.

The run at Bristol last year was 9.85 on 12# of boost and that is not a lot of boost. (I believe the STR-4 Neons have 15 from the factory) The RPMs never reached higher than 5800 in any gear. How much more of a street car could you ask for.

_________________
Nitrous cars are like old men on Viagra. Once the bottle is empty they are useless.
FJD