300 hp slant w/turbo... suggestion

[Bill Dedman]

Things to avoid in this build:

1. Ported head

2. Intercooler

3. fuel injection

4. O-rings

5. 4bbls

6. Headers

7. Race gas

Well, that is a lot of money saved if none of that stuff is necessary for a viable 300 hp, turbo slant six powerplant, but if you don't HAVE any of those items onboard, what kind of performance could you expect out of a 3,300-pound (including driver weight) A body?

And, what could you use to get it???

How about 12.95 @ 104 in a car that weighs 3,300 pounds, with driver??

Here's my suggestion:

Any year slant six block, freshly bored to 3.445"

A water/alky injector... they are not cheap, but are more insurance... and allow more boost. (This motor should see 15, maybe 20 pounds; no more.)

Six Wiseco pistons, PN PT112A45 $423.28 on ebay (http://www.ebay.com/itm/Wiseco-PT11...t-Chrysler-225-Slant-6-1-625-CH-/311238766968)

Six K-1 rods, DH7005BEH86 ebay=http://www.ebay.com/itm/K1-007BF20700-H-Beam-Connecting-Rods-Chrysler-Slant-6-7-005-in-For-Forged-Crank-/271866455377?hash=item3f4c80e551&vxp=mtr $577.00, or Molnar rods for $507.00

So, that's a lot of money, but it gives you a lot of protection from detonation... always.

The head will need to be checked for straightness, but here is where I suggest you "cheap out." Pay to have the 1.75" intake and 1.5" exhaust valves installed, but do NOT spend money on a porting job. I think, given the parameters of this engine's activities (low boost, forever,) it would be a waste of money. It would run better ported, sure, but that is $1500.00 you could save by just turning up the boost a little, I think.

NO O RINGS! Victor Rienz has a new MLS gasket that should fill the bill on cylinder sealing on this low boost engine.

Holley 2350, 500cfm carb and a Super Six intake (cheap!) with the Hangar 18 mods to the carb... a DIY job, with explicit instructions on the internet.

Stock ignition system, except for a different curve, giving a maximum of 18 degrees of boost whenever there is ANY boost present! OK to use a vacuum cannister for more advance, cruising...

Some reasonably-priced, used, Buick GN turbo, maybe from a junk yard. You're on your own here, because what I DON'T know about turbochargers, would fill several large volumes... sorry. The one on my car was given to me from a guy who said it was identical to the one on his car, a 1987 Buick T-Type (GN) that runs in the tens... It's a 66mm, Turbonetics, non ball-bearing unit. That's all I can tell you; so, Im an idiot... we knew that.

Stock lubrication system.

Stock cam, pushrods but, with 340 springs

Pishta J-pipe exhaust, with a dial-your-own 3" exhaust and tail pipe. Muffler, optional...

Stock 904 and converter.

Stock oil pan.

Stock everything else.

What do you think? Could this be done for around $2,000.00? $2,500.00??? $3,500,00?

A 300 hp motor that will have impeccable road manners (driveability,) last a long time, get decent gas mileage, and still have enough grunt to put the car into the high twelves at well over 100 mph, if you want to have some fun with it!

This is my personal pipe dream, but I honestly think it's do-able.

What do you guys think?:twisted:

PS Don't even THINK about trying this project without a wideband A/F meter.. it would be like standing a live earthworm on end... you'd nevwer get it done.... never.

One caveat; leaded gasoline is death to these meters... $91.00-worth..... don't ask me how I know... :banghead:

 

[killnine]

How would those rods and pistons protect from detonation? IS 15-20 really low boost? I'm no expert but that seems like the upper range of boost where people usually stop. Anyhow, if this kind of setup could do what you are proposing in theory, I would love to be a guinea pig.

 

[RustyRatRod]

Just build a hot 318.

 

[roccodart440]

Just build a hot 318.

more like a mild, less than 1 hp per cube 318.

 

[Dustert73]

Many people have built a "hot 318", not so much a turbo slant. I'm interested!

 

[Brandon Weaver]

How would those rods and pistons protect from detonation? IS 15-20 really low boost? I'm no expert but that seems like the upper range of boost where people usually stop. Anyhow, if this kind of setup could do what you are proposing in theory, I would love to be a guinea pig.

Rods and pistons do absolutely nothing to stop detonation. But forged pistons are a very wise choice if you are running >10psi. Actually it would be almost foolish to run anything but forged past 10 pounds. And Wiseco pistons can only be used with K1/Molnar rods, so if you want off the shelf forged pistons you have to drop at least a grand and get pistons and rods.

And no, '15-20' isn't anywhere close to 'low boost'. Anything under 10 is low boost. Here's something to compare to...

The fastest slant six in the world (last I checked) only runs 15psi

The most powerful slant in the world (again, AFAIK) runs ~20psi

If you build properly, you don't need much boost... (Shhhh! Don't tell anyone though, they think it's better to build a poor engine and the pressurize it to death, because 'boost makes up for it' and then think 300hp from 23psi is wonderful)

 

[Bill Dedman]

How would those rods and pistons protect from detonation?

I didn't say that forged pistons and rods would "protect from detonation." Nor, prevent detonation.

You're right; they won't.

What I said was (and, this is a copy and paste direct quote,) "it gives you a lot of protection from detonation" which is not the same as preventing it. Maybe I should have worded it differently, but to protect from detonation, detonation has to have already occurred, and the way it protects is, cast (stock) pistons are brittle, and crack relatively easy (compared with forged units,) while the Wiseco (and other forged slugs,) are relatively tough, with thick crowns, so they give a measure of protection you don't get with cast, OEM pistons. They can successfully endure a measure of detonation that will destroy a cast piston.

I guess I should have said "that forged pistons protect from the effects of detonation thas ALREADY occurred, not to protect from detonation from happening, a different circumstance. Sorry for the misunderstanding. ops:

 

[Bill Dedman]

IS 15-20 really low boost?

I guess it depends on your frame of reference; the slant six is an unusually strong engine, with a short (usually) forged crank, and can withstand boost levels that would destroy a lot of other engines.

Both Ryan Peterson and Tom Wolfe have made in excess of 500 horsepower by running 28-30 pounds of boost in their slants, so you tell me; is half of that (15 pounds,) not "low boost" for this engine?

Twenty pounds is, however, not low, by any standards, and if I called it that, then, I was in error. Sorry!

 

[replicaracer43]

If you really wanna run high 12s in a A body, the simpler, cheaper, and easier way to do it is with a junkyard magnum 360. Id say even doable with a magnum 318 also.

 

[Bill Dedman]

If you build properly, you don't need much boost... (Shhhh! Don't tell anyone though, they think it's better to build a poor engine and the pressurize it to death, because 'boost makes up for it' and then think 300hp from 23psi is wonderful)

"Poor engine" denotes an engine that breathes poorly. A well-built engine will have a professionally ported cylinder head that flows as much air is possible BEFORE the turbo goes on, making possible high-output, at a relatively low boost.

There's an old saying; speed costs money... how fast do you want to go?

In this case, I proposed a 300 hp slant six without even an intercooler, to keep costs down. The crux of the post was to get as much for your money as possible, aiming at 300 hp, the whole time. Forged pistons and rods fly in the face of that line of thinking, because they are not cheap. But, in the interest of long-term reliability, I swallowed hard, and recommended them because I thought they'd be worth it, on several different levels.

A first-class, ported head is going for around $1,200.00 to $1,500.00 from what I hear, these days.

You cannot achieve the kind of results you posted from a "good" engine without one; the stock head sux in the breathing department. BIG TIME!

Since the whole rationale of my post was that it might be able to build a 300hp motor for an amount of money that would not be so damaging to one's budget that it would prevent the whole project, I tried to minimize expenditures where I could.

I admitted in the article, that a ported head would, indeed, be faster, but declined to suggest it in the interest of economy.

With a forged piston/rod/crank motor, I figured the desired 300 hp would be attainable by cranking up the boost a few pounds, rather than dropping $$$$$$$ for a ported head.

Is there something wrong with that logic?

You seemed to think it was not a very good idea.


Tell me why, please. I don't think the boost will have to go over 20 pounds...

 

[RustyRatRod]

The perception that pistons cannot prevent or reduce detonation is absolutely 100% unequivocally WRONG. Pistons can be custom made with a quench pad to fill in the open portion of a combustion chamber and can and will reduce or even prevent detonation altogether. Keith Black offers SEVERAL off the shelf quench dome pistons, just for that purpose and they can make anything you want, just like any other high end piston maker.

Some of you really need to educate yourselves before saying something so stupid.

Bill was right......as he usually is.

 

[Bill Dedman]

If you really wanna run high 12s in a A body, the simpler, cheaper, and easier way to do it is with a junkyard magnum 360. Id say even doable with a magnum 318 also.

If you just want a ho hum car like everbody else's that is a good way to go.

But, if you want something that will run about the same, but garner all kinds of attention from onlookers, both at the strip and at a show, go the extra mile and build a slant motor... They are so rare as to be real attention-getters.

 

[replicaracer43]

If you just want a ho hum car like everbody else's that is a good way to go.

But, if you want something that will run about the same, but garner all kinds of attention from onlookers, both at the strip and at a show, go the extra mile and build a slant motor... They are so rare as to be real attention-getters.

It is certainly unique to build a turbo slant, and I agree with everything you said above. I considered building one for one of my project cars a while back.

 

[66Dvert]

If you really wanna run high 12s in a A body, the simpler, cheaper, and easier way to do it is with a junkyard magnum 360. Id say even doable with a magnum 318 also.

But,but,but,but! Nearly everyone does the big built (small build or just stock upgrade) V-8 thing. I always thought that my mopar was a bit different than a typical big boys toy that I sank a ton of money in.


I want to be a bit different and still run decent, do I want a 12's? I'm not sure anymore,but it better not be a 14 and up. Putting a JY 360 (that I'd have to rebuild anyway to make sure it would last) in my dart is a bit more complicated (headers,exhaust,mounts=EXPENSIVE) than the later A's and the cost goes up from there,plus I've got the /6 already and the head is done. It also helps that I have a go-fast v8 (70 challenger, 440-6paclk,4sp) that loves every gas station it goes past to cure me of the v8 habit

But to each their own and mine will be a mild turbo'd /6 if I can ever finish up getting the odd parts made that I need for my dart and get back working on it AND I can say I did it all myself, mistakes and all from bodywork,paint, wiring and custom parts. I have had a ball doing it and will start another one as soon as I can drive this one.

 

[AJ/FormS]

If it makes any difference, Bill, I understood your line of thinking,and that protection thing,perfectly.
And 1.33 hp per cid with a turbo should be easy. Make that EASY. And while Im a sucker for V8s, I do think theres something sorta sexy/cool about a seeing a head over there and a bonnet over here,and all kinds on neat stuff in-between.
If I had an itch to build one of those, I wouldnt actually care how fast or how quick it was.(mostly).
I would be doing it for some of the same reasons you are thinking of.
And when its done,and idling at 550 at the stoplight; when the light goes green, and its GO-time, that guy in the next lane will be all mixed up, while you will be giggling like a schoolgirl.
And when showing it; dont pay any attention to naysayers. One day there will be a guy in the crowd, kinda like you, dying to know stuff and actually learn things.Then your heart will sing.

 

[Brandon Weaver]

The perception that pistons cannot prevent or reduce detonation is absolutely 100% unequivocally WRONG. Pistons can be custom made with a quench pad to fill in the open portion of a combustion chamber and can and will reduce or even prevent detonation altogether. Keith Black offers SEVERAL off the shelf quench dome pistons, just for that purpose and they can make anything you want, just like any other high end piston maker.

Some of you really need to educate yourselves before saying something so stupid.

Bill was right......as he usually is.

Well aren't we in a wonderful mood today!

Look at it this way... Pistons are the number 1 cause of detonation! Just think, if the piston weren't there, you'd never have a detonation problem!

Yes, excuse me, since you've brought up exotic custom made pistons that vary application to application and there are none off the shelf for the slant... Yes, in some cases quench is helpful to reduce detonation. I figured quench was out of the subject since the slant is a 'non quench engine'. I was referring directly to the piston that Bill mentioned and posted a link to.

Since you've brought up quench, I will ask you a few questions though...

1. How low of a compression can you get a custom piston in and have quench?
2. How does quench act at what is considered by most as 'high boost'?
3. Although not quench, couldn't a dished piston give better resistance to detonation by providing a slightly better combustion shape?

The reason I ask this, I believe the Subaru guys run quench on stock and mild (say, below 15#) but their wilder engines I think they say the quench makes it too turbulent and actually promotes detonation? I may be wrong, sometimes I really need to educate myself before saying something so stupid. (Name's Brandon btw...)

And Bill: You seemed to think it was not a very good idea. Tell me why, please

I just find it odd that you'll recommend someone modify their own carb for blow thru, but you don't think one could improve on the head on their own? I mean, sure, it won't be no Dutra/Cox/Jeffries head, but it'd be better than just a stock head with O/S valves...

BTW, I actually priced a Dutra head not too long ago. 1.7/1.44 valves, all chambers evened, so on and so forth. It wasn't from Dutra himself, the feller had bought it, never used it, and now wants to sell it. I wouldn't be surprised if it flowed ~200cfm on the intake at somewhere close to .600 lift (I've seen Doug post numbers that he has got that with the 1.7 valves) Anyways, the dude wants $1200, and I'm sure that's what he payed for it. So your prices may be a skosh high. It'd be nice if someone could do a step-by-step port it yourself type thread like we have for 302 and Magnum heads...

 

[Bill Dedman]

Look at it this way... Pistons are the number 1 cause of detonation! Just think, if the piston weren't there, you'd never have a detonation problem!

No, that's like saying crankshafts rod throws are the cause of detonation because if one weren't there, pushing up the rods and pistons, there would be no detonation.

Detonation is caused (primarily) by cylinder pressure that has increased to a value that is beyond the capablity of the octane available, to control. Given sufficient octane, there will be no detonation. In fact, the textbook definition of octane is "resistance to detonantion."

And Bill asked, "You seemed to think it was not a very good idea. Tell me why, please."

the dude wants $1200, and I'm sure that's what he payed for it. So your prices may be a skosh high.

In one post (to you, in fact,) I said, "A first-class, ported head is going for around $1,200.00 to $1,500.00 from what I hear, these days." But, in another, I said "you could save $1500.00" At 76 years old, I am lucky to be able to SEE the screen; give me a break... I need one!ale:

Insofar as porting your own head, I have never done that. Have you? The slant six head, being cast iron and having long, narrow passages. looks like a ***** to port; a job I wouldn't wish on a dog... Conversely, most waste gates are adjustable... and, I am by nature, lazy... so, I was just being "ME." Turn up the boost, Elmer... LOL!

 

[AJ/FormS]

A guy very nearly needs to forget about quench in a turbo engine.
To run 15psi, the Static cr will need to be down in the basement,and the cam very conservative.That translates to 80cc or 90cc or more of TOTAL chamber volume.That would make for a pretty odd quench-dome piston. And all the expanding-gas-force would be off-axis. How long would the skirts suffer that?
Now, since Bill is ok with alky/water injection, perhaps the cr can be raised to a level where a quench-dome is viable. Then the off-boost performance can increase, along with highway cruising economy.A very delicate balancing act, to be sure.
Subarus depend very heavily on the turbo being there.They have little to no, off-boost performance. If I had a Subbie, I would hope that if the turbo died, it would happen in my driveway.At that point a Forrester becomes about a 2liter 3600plus pound slug. An Impreza/WRX would be a hair better.

Go Bill, GO!

 

[Bill Dedman]

If it makes any difference, Bill, I understood your line of thinking,and that protection thing,perfectly.
And 1.33 hp per cid with a turbo should be easy. Make that EASY. And while Im a sucker for V8s, I do think theres something sorta sexy/cool about a seeing a head over there and a bonnet over here,and all kinds on neat stuff in-between.
If I had an itch to build one of those, I wouldnt actually care how fast or how quick it was.(mostly).
I would be doing it for some of the same reasons you are thinking of.
And when its done,and idling at 550 at the stoplight; when the light goes green, and its GO-time, that guy in the next lane will be all mixed up, while you will be giggling like a schoolgirl.
And when showing it; dont pay any attention to naysayers. One day there will be a guy in the crowd, kinda like you, dying to know stuff and actually learn things.Then your heart will sing.

Thank you for your insightful comments; they made me smile...


You know what makes my heart sing? The feeling I get halfway through 1st gear, when this thing comes "on the cam" so-to-speak, and shoves me back in the seat like it has 500 cubic inches... I can't wait for 20+ pounds of boost!!!


Now, if it would only back up...:banghead:

 

[Brandon Weaver]

No, that's like saying crankshafts rod throws are the cause of detonation because if one weren't there, pushing up the rods and pistons, there would be no detonation.

Detonation is caused (primarily) by cylinder pressure that has increased to a value that is beyond the capablity of the octane available, to control. Given sufficient octane, there will be no detonation. In fact, the textbook definition of octane is "resistance to detonantion."


In one post (to you, in fact,) I said, "A first-class, ported head is going for around $1,200.00 to $1,500.00 from what I hear, these days." But, in another, I said "you could save $1500.00" At 76 years old, I am lucky to be able to SEE the screen; give me a break... I need one!ale:

Insofar as porting your own head, I have never done that. Have you? The slant six head, being cast iron and having long, narrow passages. looks like a ***** to port; a job I wouldn't wish on a dog... Conversely, most waste gates are adjustable... and, I am by nature, lazy... so, I was just being "ME." Turn up the boost, Elmer... LOL!

Bill, the piston thing was meant as a joke... in no way, shape, or form was I the least bit serious about pistons being the cause of detonation. Just my dry way of humor I suppose...

Yes, I know you said 1200-1500, I'm saying 1200 is more the upper limit from my perception, and the local jokel may do a porting job (If you trust him, and he has a bit of experience and a flowbench) for a little bit cheaper than the big slant guys charge. And with the valve like you talk they may still be able to get 200cfm, or at least close. I weren't meaning to give you too hard of a time!

Yes, I have done a little bit of porting on my own head. I've got it tore apart now and am doing a little more. Who knows of it'll even go back together... You need some long burrs, I mainly have just worked on smoothin the bowls, narrowing around the valve guides, gasket match (you'd be surprised how the gasket lines up... or don't...) The cast iron means work is slow, but a little more... Forgiving? It's harder to get ahead of yourself and really bugger something. Plus, mine is the later 'peanut head'. Heaver, but thicker and able to be opened up more.

Also, one of the things I was getting at: The less boost it takes to reach this goal, the cooler the charge, and the less you should have to worry about detonation. Maybe even get away with stocker pistons if 10lbs or under. (Though I would still buy these as an insurance, especially since all slants that came in A-Bodies are forged and have forged rods; K1/Molnars are overkill for this app. https://www.flatlanderracing.com/hpkits-chrysler.html )

 

[killnine]

Honestly I go back and forth between turboing my slant and just dropping something else in it. I really want to turbo it, but I just want to find someone else running the right combo that gets me there, so I don't have to figure it all out myself. If I have to go the total experimentation route, I'll just drop in something else. Bill's concept is the simplest I've seen yet, and matches the closest with what I'd like to do. So I'm totally into it. I need to plan the whole thing out before I actually do it though, as I would prefer to limit downtime. I'm still on the hunt for a good turbo too.

 

[AJ/FormS]

Killnine,
"If I have to go the total experimentation route, I'll just drop in something else."
"I would prefer to limit downtime."
These words speak to a larger,replacement engine.
You need to consider your; skills,tools,shopspace,budget,and most importantly, TIME.
A turbo-project will require plenty of each.

 

[Bill Dedman]

Killnine,
"If I have to go the total experimentation route, I'll just drop in something else."
"I would prefer to limit downtime."
These words speak to a larger,replacement engine.
You need to consider your; skills,tools,shopspace,budget,and most importantly, TIME.
A turbo-project will require plenty of each.

What he said...

 

[Bill Dedman]

Bill, the piston thing was meant as a joke... in no way, shape, or form was I the least bit serious about pistons being the cause of detonation. Just my dry way of humor I suppose...

Yes, I know you said 1200-1500, I'm saying 1200 is more the upper limit from my perception, and the local jokel may do a porting job (If you trust him, and he has a bit of experience and a flowbench) for a little bit cheaper than the big slant guys charge. And with the valve like you talk they may still be able to get 200cfm, or at least close. I weren't meaning to give you too hard of a time!

Yes, I have done a little bit of porting on my own head. I've got it tore apart now and am doing a little more. Who knows of it'll even go back together... You need some long burrs, I mainly have just worked on smoothin the bowls, narrowing around the valve guides, gasket match (you'd be surprised how the gasket lines up... or don't...) The cast iron means work is slow, but a little more... Forgiving? It's harder to get ahead of yourself and really bugger something. Plus, mine is the later 'peanut head'. Heaver, but thicker and able to be opened up more.

Also, one of the things I was getting at: The less boost it takes to reach this goal, the cooler the charge, and the less you should have to worry about detonation. Maybe even get away with stocker pistons if 10lbs or under. (Though I would still buy these as an insurance, especially since all slants that came in A-Bodies are forged and have forged rods; K1/Molnars are overkill for this app. https://www.flatlanderracing.com/hpkits-chrysler.html )

Brandon, I KNEW you were joking; I was just jerking your chain.... by giving you more of the same... friends???

I am in no way qualified to discuss the vagaries of quench in boosted motors, so I'll bow out of that discussion now...

I have read enough about porting to know that what LOOKS like it will work sometimes will and sometimes won't... it's a lot harder to put material back than it is to take it off... So, I'll leave it to the Mike Jeffries of the world to create flow, if they can.

As an aside, I saw a quote from Mike, or somebody in his area of expertise, making a job quote on porting a slant 6 head, complete with swirl-polished valves, and it was $1,500.00, about a year ago. Just sayin'...

I wanted 300 hp for this engine (not mine; the one being discussed,), and didn't think it was possible with these parts, you mentioned. Stock pistons would be limited to 10 pounds of boost. My engine just made 233 hp with ten pounds of boost, but I had a leak in the cold-side plumbing, so the test was inconclusive. I plan on doing a lot more testing with the leak (and, transmission) fixed, so, one of these days, soon, we may have better info to work with.

If I can't make 300hp with 20 pounds of boost in my motor, I'm thinking, there's something wrong... maybe, builder/operator error.ops:

300 hp should put my car thru the quarter in 12.50 seconds @ 109 mph.

We'll see... rayer:rayer:rayer:

 

[Rockerdude]

Always an interesting read when you post Bill. Make me want to take the time to put a 225 together, slants are constantly being thrown to the curb for v8s. Mostly because its so much easier and faster for most to go to a small block or heavy big block. I've always liked the thought of a well thought out turbo 6 cylinder setup. If I got that far though, I would want to think of a good fuel injection method too.. I never liked the fuel distribution with a 4 barrel on a slant six because of the unequal length intake runners, and the way the carb sits sideways (at least on my offy intake).