Interest in Performance Parts for slants?

-
I am here in indy and have a few, but Bill is right without the proper head work and all the other goodies your pissin in the wind. I have some guinnea pig motors iam working on. Do you have anything started.

Thanks for the support, Sleeper, but my point was, because of the narrrow bore spacing parameters, even WITH the proper head work and the biggest valves you can stuff in there, making a deep breather out of a normally-aspirated slant six just isn't gonna happen.

Consider this:

The slant 6 has the same identical cylinder volume as a 302 V8 (1967 Chevy Z-28.)

Slant over-size valves 1.75" intake/1.5" exhaust

Chevy 302 V8 STOCK valves 2.02" intake/1.6" exhaust

Total valve area:

Slant: 2.40 intake + 1.77 exhaust = 4.17 sq. in. of total valve area per cylinder
Chevy: 3.20 intake + 2.01 exhaust = 5.21 sq. in. of total valve are per cylinder

That is a difference of TWENTY FIVE PERCENT!

That is a comparison of a STOCK 302 Chevy (37.75 cu. in/cyl.) to a "BIG VALVE" slant six (also 37.5 cu, in./cylinder.)

That is what valve size most people end up with in their ported slant six heads, as the largest practical head diameters for the two valves. There are offset guides available to install still larger sizes of valves, but with the 1.75" X 1.5" valves taking up 95% of the bore, installing larger diameter valves begs the question of shrouding on the combustion chamber walls and/or cylinder walls.

Anyway, that is the problem; resitricted valve size that is dictated by the (relatively) small cylinder diameter.

The biggest ports in the world won't help that problem. It all boils down to the weak link in the chain, which in this case, is the size valves that will fit.

That's why aluminum cylinder heads, electronic fuel injection, roller cams and exotic intake manifolding are just band-aids on a problem that can't be fixed with bolt-ons; the only thing that will cure this lack of breathing ability is more cow bell... er, in this case, forced induction of one kind or another.

My personal choice is turbocharging because lying on its side as it does, the slant 6 leaves a LOT of room in even the generation I A-Bodies for a turbo and plumbing, but any kind of supercharger or turbo will work well, I think, and N20 also can be used to get around the /6's breathing problems.

But EFI on ANY kind of a N-A manifold isn't going to do it...

Just my 2-cents...
 
Sobie:

I appreciate the fact that you have the intelligence and interest (and, MOPAR mentality) to want to try to make some parts that will help in trying to get more air into and out of a slant six motor, so more horsepower can be made.

That's the whole idea, isn't it; to make more power?

Well, the sad fact is, doing that with a slant six motor that is normally-aspirated, is more of an up-hill battle than it should be because, the cylinder head was designed for a 170, and never changed in regards to head flow (when the engine was stroked to a 225) and the result is a motor that, no matter how good the design of the intake sytem might be, all comes to a screeching halt at the OEM head/port/valve infrastructure and although small gains can be made, there is simp[ly no way to move a LOT of air through the valves and ports of a normally-aspirated slant six that is 35-percent larger than the engine that the head was designed to feed..

Guzzi Mark (FABO name) has managed to make a normally-aspirated slant six look extremely good on the drag strip by putting an unusually well-built engine in a very light car that really HOOKS. It turns in times that make me shake my head in wonder, but when you get right down to it, the engine is not actually making all that much power... it just LOOKS like it is because he knows what he's doing when it comes to the application of what power he DOES have to work with.

He uses every trick in the book and a few that were never in a book, I think, to make his car quick, and it IS quick; leaves like a GOOD V8 car...

But, most folks aren't able to take advantage of his expertise and will never have a 2,350-pound A Body, (like his is,) with most weighing in at around 3,200 pounds.

A slant six that makes 1.3Hp/Cu. In. will make 225 X 1.33 or about 295 hp.

Not many normally-aspirated slants will make that much horsepower on gasoline unless they're all-out, full-race motors, which aren't very streetable.

In a 3,200 pound car, 295 horsepower willl get you a time card with a high 12-second number on it, IF everything is maximzed for the quarter-mile.

Street driveability will be severly compromised in a variety of ways.

Most slant six owners if they want more power, would like to be able to bolt on a few hop-up components, like say, maybe a 4-bbl intake manifold, headers, hi-compression pistons, a wilder cam, and a good, size-matched 4bbl carb, and go racing.

They can do that IF they are going to be happy with a low 14-second car that runs mid 90's in the quarter

The absolute best EFI system in the world MIGHT pick their car up three tenths, and that's stretching it. MAYBE 100 mph in the quarter.

I'm not saying that you can't have a lot of fun with such a car; what I'm saying is that the cost of a custom-designed EFI fuel injection system is going to be out of line with the amount of HP gains it produces.

Bang for the buck will always be a heavy player in this game.... and, in this case, it's just not there. The potential for sizeable horsepower gains from a different intake manifold and injection system is not going to happen.
However, there IS a part that you could produce that would actually offer great bang for the buck, be relatively easy to make for sale, has NO moving parts and has what I believe to be a ready market in the slant six commuity.

I didn't have anything to do with the design of this part and I don't even KNOW the guy who did think it up, but it's a really neato part that has a lot of potential, as regards bang-for-the-buck.

His FABO screen name is "PISHTA" and he built one of these for his own low-buck turbo installlation, and best I can tell, it works on all levels!

He took a piece of 2-1/2" small-radius U=Bend exhaust tubing and attached a flange that would bolt onto the stock slant six exhaust manifold on one end, and welded a turbo mount on the other end (on the same plane.)

You bolt it onto your stock /6 exhaust manifold (where the exhaust down-pipe used to bolt on) and, with no welding on the manifold, now have a turbo mount that will work well, and won't make your cast-iron manifold any more prone to cracking than it was before you made the change. Stock slant 6 exhaust manifolds are prone to cracking; welding a turbo flange onto one only makes the probability that they will crack that much more likely.

All you'd need is to measure the space availible, buy some U-Bends of the appropriate size, acquire some 2-1/2" flanges that can be welded to the U-Bends and attach the turbo mount to the other end of the U-Bend, and you're done!

This system mounts the turbo on a horizontal mounting flange pretty much over the motor mount, I think, and if you put the battery in the trunk (where it belongs,) there's an abundance of space to work with.

I wish I'd thought this up... but, I'm not that smart. It is SUCH a good idea!!!:blob:

With a setup like that, you could add a Snowperfformance Boost Cooler alky injector and run 15 pounds of boost through a stock motor and make an easy 250 HP on pump gas, never having removed the head or cam.

Don't take that to the bank, but I really believe, having read what I have about how slant sixes respond to turbocharging, that it is true...

You asked for opinions; that is mine... and it's all only JUST my opinion.

But the deal about the strangulated nature of that original 170 head (and, they all are; the 225's are identical,) is a pretty educated guess. The ported, big-valve heads are better, but still don't flow all that well, normally-aspirated.

Forced induction can be a way around that. It can be simple (cheap) or complicated (NOT cheap) and that's the engine builder's choice...:coffee2:

I hope you'll give this some serious consideration; the slant six commumnity NEEDS that part (turbo adapter!)

BTW, you can't grind a cam on a lathe...:director:
GREAT! I just read this whole post, now i'm gonna be late for work. BTW, I plan on copying Phista's setup.
 
I agree with the general census. I put a 3.91 in the dart and had nothing but overheating problems with daily driver,went back to the 2.76 and made a freeway flyer that smokes quiet a bit of the competition and stays cool at 95-101. I love it. Just saying
 
GREAT! I just read this whole post, now i'm gonna be late for work. BTW, I plan on copying Phista's setup.

Well, I hope I didn't waste yout time AND make you late for work!

Wouldn't t be nice to be able to mail-order that U-Bend with the necessary flanges already welded on it, for a reasonable price, say $75.00-$100.00?

We spent $1,000.00 building our header and did all the work ourselves except for the welding and coating. I'm not even sure it will make more power than PISHTA's U-Bend setup.

Go for it!!!:cheers:
 

Attachments

  • js640_100_3489-2.jpg
    116.3 KB · Views: 1,079
Well, I hope I didn't waste yout time AND make you late for work!

Wouldn't t be nice to be able to mail-order that U-Bend with the necessary flanges already welded on it, for a reasonable price, say $75.00-$100.00?

We spent $1,000.00 building our header and did all the work ourselves except for the welding and coating. I'm not even sure it will make more power than PISHTA's U-Bend setup.

Go for it!!!:cheers:

Another good idea that isn't mine!...how come there seems to be so many?
\
 
Well, I hope I didn't waste yout time AND make you late for work!

Wouldn't t be nice to be able to mail-order that U-Bend with the necessary flanges already welded on it, for a reasonable price, say $75.00-$100.00?

We spent $1,000.00 building our header and did all the work ourselves except for the welding and coating. I'm not even sure it will make more power than PISHTA's U-Bend setup.

Go for it!!!:cheers:

BTW...I made it with 3 minutes to spare!
 
Just picked up my mini starter Bill before i go about the fun game of headers.

A mini starter is a good place to start (no pun intended) but before you decide on a header design, you really should at lease LOOK at the deal PISHTA came up with. I think it will save a lot of people a lot of grief... and money!

Good luck!!! :D
 
I have a triple SU set-up for the slant. I have seen some kind of adapter that bolted to this style of manifold that utilized 3 OEM Holley 1920s or Carters. It was just a short 90 elbow. I should have bookmarked where I saw it.

29e2jpk.jpg


(Before Leanna worked on it)
 
would love to see a intake like this for the slants


Just make one. That looks simple. some 1.5 EMT for the runners, Ebay intake flanges, some 2X3 rectangular tubing tying them together, cap the ends and cut your favorite carb mounting holes. It would flow at least as well as that relic.
 
Probably by the end of next year i'll have a kit for a 6/71 and maybe a 4/71 blower, brackets and all.
 
Probably by the end of next year i'll have a kit for a 6/71 and maybe a 4/71 blower, brackets and all.

Would that include maybe a plate for a small M-45/60 Eaton? you can score those for $100 off a SC Buick Regal or Benz at a bone yard!
 
Would that include maybe a plate for a small M-45/60 Eaton? you can score those for $100 off a SC Buick Regal or Benz at a bone yard!

i think you mean M90's and M112's. problem is both need to be blow thru, and they both need an intercooler to be worth while, hence me going the /71 route.

and im looking for 20 psi and mid to high tens at 5% underdriven with the 6/71
 
yup, your right. Sounds intriguing.....Looks like a weird setup anyway short of EFI. looking forward to that part!
 
splice together 2 slants and make a v-12. YES a joke

Brabus offers a V6 engine block for the Smart, with performance internals. The Triumph TR7 engine is 1/2 of the Stag V8 (as evidenced by the cross-flow head and location of the distributor). The latter was criticized as unreliable but British enthusiasts have further developed the engine and, with regular maintenance, runs reliably.

A V12 from the slant 6 would need cross-flow heads and the relocation of the distributor - effectively, a new block and heads.
 
Probably by the end of next year i'll have a kit for a 6/71 and maybe a 4/71 blower, brackets and all.

I would be very interested in that. I love the idea of a turbo, but honestly it seems a bit above my level of wrenching without a kit. I'm currently going the n/a route with an Offy intake, Eddy 500 4bbl, an Erson 280/270 cam, ported and planed cylinder head with big valves, hardened seats, 340 springs and .100 shaved off the head. If I can get it above 200HP I'd be thrilled, but I still have my doubts I'll ever get there without a boost. I've been toying with going nitrous, but that may be more trouble than its worth for a 99.9% street car.

Has anyone done turbo and a/c at the same time? I would think there wouldn't be clearance issues since the compressor is way up front, but I wasn't sure.

Great thread and a lot of great ideas.
 
Brabus offers a V6 engine block for the Smart, with performance internals. The Triumph TR7 engine is 1/2 of the Stag V8 (as evidenced by the cross-flow head and location of the distributor). The latter was criticized as unreliable but British enthusiasts have further developed the engine and, with regular maintenance, runs reliably.

A V12 from the slant 6 would need cross-flow heads and the relocation of the distributor - effectively, a new block and heads.

Here's a V8 Caddy engine from 1929....it isn't crossflow like usual.
The intake and exhaust is in the valley....like 3500 series CAT engine.

http://www.secondchancegarage.com/p...-cadillac-341b/1929-Cadillac-341b-engine1.jpg
 
I would be very interested in that. I love the idea of a turbo, but honestly it seems a bit above my level of wrenching without a kit. I'm currently going the n/a route with an Offy intake, Eddy 500 4bbl, an Erson 280/270 cam, ported and planed cylinder head with big valves, hardened seats, 340 springs and .100 shaved off the head. If I can get it above 200HP I'd be thrilled, but I still have my doubts I'll ever get there without a boost. I've been toying with going nitrous, but that may be more trouble than its worth for a 99.9% street car.

Has anyone done turbo and a/c at the same time? I would think there wouldn't be clearance issues since the compressor is way up front, but I wasn't sure.

Great thread and a lot of great ideas.

im probably sitting at about 215 wheel now in my motor and that should be a solid 13 second car but havn't been able to put more time into it...

as for the turbo manifold i just got me flanges to make some for sale, lucky for you my 73 is an A/C car as was gonna try to make it work with that! battery has to be relocated though...
 
im probably sitting at about 215 wheel now in my motor and that should be a solid 13 second car but havn't been able to put more time into it...

as for the turbo manifold i just got me flanges to make some for sale, lucky for you my 73 is an A/C car as was gonna try to make it work with that! battery has to be relocated though...

I think that battery re-location should be the first thing done to car that's slated for forced induction. Moving it to the trunk clears up a lot of space that can be used for a turbo, a belt-driven, centrifugal supercharger or other packaging considerations having to do with the extra hardware associated with blowers. The extra weight on the back wheels is a bonus... :D
 
I think that battery re-location should be the first thing done to car that's slated for forced induction. Moving it to the trunk clears up a lot of space that can be used for a turbo, a belt-driven, centrifugal supercharger or other packaging considerations having to do with the extra hardware associated with blowers. The extra weight on the back wheels is a bonus... :D

no i agree, just one of those things!
 
Neat. I was planning to trunk the battery anyway. Early A clearance is tough enough as it is. Looking forward to hearing more.
 
-
Back
Top