Your thoughts on intake/exhaust choices ??

halfafish

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This tale is for my 82 D150, bought as a dead dog and needing a new engine. Details are here:

Mission Creep on a D-150

Because I sometimes learn the hard way even though I do a lot of research and try hard not to screw up, we have this thread where I finally discovered I had too much timing and was detonating, which trashed my rod bearings.

Ideas on what's causing my click/tick/rattle noise?

As punishment for being a tuning goon, I got to pull the engine and tear it down to bare bones nothing. The crank was OK, the rods were OK, I got new rod bearings and main bearings and I'm on the way to put it back together again.

This is an ordinary driver truck. I will take it to the track for grins but it's for dump runs and so forth. I want it to be a solid runner that I can take anywhere. I put 700 miles on the fresh build before I pulled it. I was reasonably happy with how it ran. Engine details:

82 slant, freshly bored .030 over. It's a hydraulic head but I swapped out the innards for solid lifters and valve train gear.
Lean burn junk removed.
Cam is a 2106R from Oregon Cam Grinding. It is 214/210 @ .050, 444/434 lift, 108 LS on a 104 intake centerline.
Trans is an A833OD.
Gears are 3.55 but having run this thing a bit, I'm thinking I need to go with 3.91 to get the OD gear up in the power band better. It starts pulling at about 1600 and does well (by my limited experience) to about 3500 or so. I took it to 4500 a few times but that's not something that will happen often.
Tires are 29", 235/75R15 mud-and snows.
Ignition is a super six distributor with HEI conversion.
Intake is a Clifford 4-bbl with the water heat provision.
Carb is an Edelbrock AVS2 500.
Exhaust is Clifford shorties, 2-1/2" two-into-one all the way to the tailpipe through a Dynaflow Dynamax.
The head was shaved to get to about 8.5:1 static which got me about 7.6:1 dynamic compression. It got a clean-up pocket porting and a full valve job with oversize valves (1.68/1.44 IIRC).

So here's my question. If I want to change anything on the engine, now is the time. As mentioned above, I was fairly happy with how the truck ran in its original configuration. I have many options for intake, carb, and exhaust. What are recommendations for getting the most torque out of this engine? Other parts I have on hand:

INTAKES/CARBS
Clifford adapter to run a 2-bbl on the current 4-bbl intake.
Offy 4-bbl intake.
Holley 390 4-bbl carb
Super Six intake with an almost new Carter BBD.
An old Offy 2x1 intake that was modified for 2x2, running dual Weber downdrafts.

EXHAUST
A factory cast iron exhaust manifold that was VERY nicely ported and gasket matched, then the outlet was hogged out for a turbo with a square flange welded in place for the turbo. One drawback for this one is the heat stack was cut off so there would be no manifold heat.
Dutra Duals
Dual Dutra Duals

I'll be running this info on my two favorite sites, FABO and slantsix.org. Both have a tremendous number of slant gurus. What is your experience with any of the above parts, what would you recommend, and why?

TIA, and let the games begin!
 
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Jim Kueneman

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So I spent a lot of time with Performance Trends simulator looking for the same thing on the wife's Dart. All the torque I could get under 3000 RPM on the 225. You have done most everything you can do.

1) Crank up the compression (I went to about 8.8:1)
2) The 1206 puts in the max 200 psi cranking pressure you want for a nice street engine (I have this as well) with the above compression.
3) What really seemed to help as well was Dutra Duals then take them right behind the transmission crossmember for the "Y". That was the length required for scavenging at low RPM (I did this). Also keep the pipe diameter small from the Duals to the "Y". Too big for the cubic inches and the exhaust pulse will die out before it get to the "Y" and create a backward pulse in the other half of the "Y". Think I used 1.75".

Don't over carb it for torque. Lots of CFMs are for high RPM. Around 375-425 CFM seems like the perfect spot for the above components. I went with the Offy dual one barrels and new Daytona 1904 knockoffs. The Super Six would be all you need.

There is a limit to how much torque you can get and have a streetable motor. Cubic Inches, cranking compression and exhaust scavenging are are the main drivers. The first one is set, second one is set by compression and the camshaft and the third is just icing on the cake.

If you look at the equation for Torque in an engine it is simply
Torque = displacement *MEP (Mean Effective Pressure)
you can see there is very little you can do once you have the cam that give you as close to 200 PSI as you can. After that it is all second order effect like scavenging with the exhaust collector ~45" back for low end scavagening.
 
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Charrlie_S

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Just a quick FYI. You stated about swapping to solid lifter valve gear. What rocker shaft did you use? The hydro, or the solid? They are different. The oil holes for the rocker arms are in a different location, between the two. You must use the correct shaft, for proper rocker arm oiling. If you look at the bottom of the shaft, the hydro shaft has the oil holes in line with the shaft mounting holes. The solid shaft has the oil holes offset from the mounting holes.
 

halfafish

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1) Crank up the compression (I went to about 8.8:1)

I got the static compression to about 8.5:1 when I built it - I wanted it to run OK on junk gas. I do have one of the steel shim head gaskets from the group buy organized by @Charrlie_S. I'll do the math and see what using that would get me for compression. I will need to see if that gasket will fit a hydro head or not, stay tuned.

Just a quick FYI. You stated about swapping to solid lifter valve gear. What rocker shaft did you use? The hydro, or the solid? They are different. The oil holes for the rocker arms are in a different location, between the two. You must use the correct shaft, for proper rocker arm oiling. If you look at the bottom of the shaft, the hydro shaft has the oil holes in line with the shaft mounting holes. The solid shaft has the oil holes offset from the mounting holes.

Thanks for the heads up sir. I swapped in the solid rocker arm, rockers, and bolts from a 78 Volare along with getting the original juice cam reground for the solid specs.
 

Duggie

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This tale is for my 82 D150, bought as a dead dog and needing a new engine. Details are here:

Mission Creep on a D-150

Because I sometimes learn the hard way even though I do a lot of research and try hard not to screw up, we have this thread where I finally discovered I had too much timing and was detonating, which trashed my rod bearings.

Ideas on what's causing my click/tick/rattle noise?

As punishment for being a tuning goon, I got to pull the engine and tear it down to bare bones nothing. The crank was OK, the rods were OK, I got new rod bearings and main bearings and I'm on the way to put it back together again.

This is an ordinary driver truck. I will take it to the track for grins but it's for dump runs and so forth. I want it to be a solid runner that I can take anywhere. I put 700 miles on the fresh build before I pulled it. I was reasonably happy with how it ran. Engine details:

82 slant, freshly bored .030 over. It's a hydraulic head but I swapped out the innards for solid lifters and valve train gear.
Lean burn junk removed.
Cam is a 2106R from Oregon Cam Grinding. It is 214/210 @ .050, 444/434 lift, 108 LS on a 104 intake centerline.
Trans is an A833OD.
Gears are 3.55 but having run this thing a bit, I'm thinking I need to go with 3.91 to get the OD gear up in the power band better. It starts pulling at about 1600 and does well (by my limited experience) to about 3500 or so. I took it to 4500 a few times but that's not something that will happen often.
Tires are 29", 235/75R15 mud-and snows.
Ignition is a super six distributor with HEI conversion.
Intake is a Clifford 4-bbl with the water heat provision.
Carb is an Edelbrock AVS2 500.
Exhaust is Clifford shorties, 2-1/2" two-into-one all the way to the tailpipe through a Dynaflow Dynamax.
Head was shaved to get 7.6:1 dynamic compression.

So here's my question. If I want to change anything on the engine, now is the time. As mentioned above, I was fairly happy with how the truck ran in its original configuration. I have many options for intake, carb, and exhaust. What are recommendations for getting the most torque out of this engine? Other parts I have on hand:

Clifford adapter to run a 2-bbl on the current 4-bbl intake.
Offy 4-bbl intake.
Holley 390 4-bbl carb
Super Six intake with an almost new Carter BBD.
An old Offy 2x1 intake that was modified for 2x2, running dual Weber downdrafts.

Original cast iron exhaust manifold that was VERY nicely ported and gasket matched, the outlet was hogged out for a turbo but the heat stack was cut off so there would be no manifold heat.
Dutra Duals
Dual Dutra Duals

I'll be running this info on my two favorite sites, FABO and slantsix.org. Both have a tremendous number of slant gurus. What is your experience with any of the above parts, what would you recommend, and why?

TIA, and let the games begin!
Man, reading your list of parts and history left me grinning like a possum eating poop! If a house in your neighborhood goes up for sale, let me know. It wouild be a blast being your neighbor. In the meantime, I'm following this thread. :popcorn:
 

volaredon

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Send me the Clifford intake. Then you don't have to worry about whether to run it or not! I'll run it on mine for ya
 

j par

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:popcorn:...
Screenshot_20201123-171538.png
 

Bewy

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You have about the best value-for-money induction system that you can buy! Why change it????
Cruise on the small primaries of the Edel carb for great economy & throttle response; if you want more ooomph, open the secondaries......
 

RustyRatRod

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The more I learn about these engines, the more I see that they were terribly restricted on the exhaust. I think the number one biggest thing you can do is open up the stock manifold outlet to 2.5", port it OR put headers on it. Even the Super Six option didn't do that. While they did use a bigger head pipe, it still had to go through the puny *** 1 7/8 outlet on the manifold, so the bigger pipe was useless as tits on a boarhog. Couple the exhaust mods with the Super Six intake and a 318 Carter BBD and you'll have something. Add a hotter cam and you're even more on the way. Slant sixes respond well to mods, just like any other engine. You just need to remember, they aren't a V8.
 

Charrlie_S

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Over the last 40 years or so, I have found almost any thing you do (within reason) to a stock slant six, will be an improvement. It almost seems like you can do no wrong.
 

MOPAROFFICIAL

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Get a header.
The cam is small. My slant was done revving by around 4800 rpm with the MP .460 lift 260 duration, cruised the freeway at 32-3400 rpm with 3.55 gears going about 70-75 mph...cranked about 150 psi.

I would aim for 7.8-8.1 dynamic/cranking.
The static can be low..but you dont want the dynamic to be low if you want good torque/response everywhere.
It just sounds like the small cam is a hair too small and the compression is soft.
Though you you say you rattled the rod bearings out of it... I wish I knew you better..I'd have told you to just pull the pan and change the rod bearing, oil n filter and get back on the road after dialing your timing curve. The slants I had...had a really loooong curve...I had took the springs out for mr.gasket ones I remember...holley 350 2 brl was the best carb to drive and travel.
Header or lack of... is a big issue with caming these. Need one. People change valves and grind away... the ratios get all boogered...thing could choking on its own **** .lol
 

halfafish

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You have about the best value-for-money induction system that you can buy! Why change it????

I'm not necessarily burning with desire to make changes. I am seeking all the torque I can get out of this thing. If changes will get me further down that road, now is the time to do so.

You just need to remember, they aren't a V8.

Yup - agreed. I have no illusions on this thing being a terror. It will stay a slant, just hopefully a strong one that meets my goals.
 

halfafish

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I'm running this info over on .org as well as here. One of the suggestions was to swap to the Offy intake as it's more suited to street driving, while the Clifford is intended more for high RPM use which won't happen here. Swapping these is easy-peasy and will let me put on the BBD to check that out, and also a quick swap back to either 4-bbl if that is a better deal.

Does anyone have experience/opinions on using the Clifford shorty headers or swapping to Dutra Duals?
 

Killer6

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I'm running this info over on .org as well as here. One of the suggestions was to swap to the Offy intake as it's more suited to street driving, while the Clifford is intended more for high RPM use which won't happen here. Swapping these is easy-peasy and will let me put on the BBD to check that out, and also a quick swap back to either 4-bbl if that is a better deal.

Does anyone have experience/opinions on using the Clifford shorty headers or swapping to Dutra Duals?
How long are the primaries & what diameter on those Cliffy Shorties?
 

j par

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This is an ordinary driver truck. I will take it to the track for grins but it's for dump runs and so forth. I want it to be a solid runner that I can take anywhere. and let the games begin!
With the goal in mind everything extra you seem to be doing is for those grins you're trying to get at the drag strip...
I can tell you from experience with that transmission rear end in that truck there isn't anything you can do that's going to make any kind of massive world of a difference to that slant six.... The V8 truck that I had with the same running gears and transmission well tuned was just a tick less of a turd... It's my opinion you've already thrown way way too much money and time at this engine with the goals I quoted in mind... And remember I'm not putting down the slant six whatsoever it's a great motor for exactly what you want it to be used for with standing grins at the drag strip..
In that's 700 miles how many runs to the dump did you make..:rolleyes:...
 

Duggie

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And I’d buy the Super Six intake and card to help finance your adventures!

And I gotta ask; How does one guy end up with two Dultra exhaust manifold sets?
:poke:
 

halfafish

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With the goal in mind everything extra you seem to be doing is for those grins you're trying to get at the drag strip...

Not really. A little more grunt for pulling power is what spurred this thread. I was OK with it as it ran, just figuring if it's in pieces there is no more trouble putting it back together with different parts instead of the same parts. And I already own all the parts, too. :D

It's my opinion you've already thrown way way too much money and time at this engine with the goals I quoted in mind...

Well thank goodness it's not your time, your money, your effort or your truck. I shall soldier on with my (sadly) steep learning curve. Besides, yours is already way nicer than this one will ever be, and that's with it still in a bunch of pieces in your garage.

In that's 700 miles how many runs to the dump did you make..:rolleyes:...

And it made two dump runs already!
 

halfafish

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And I’d buy the Super Six intake and card to help finance your adventures!

And I gotta ask; How does one guy end up with two Dultra exhaust manifold sets?
:poke:

When I get done putting all my slants together, I will be selling off my extra parts so I will keep you in mind. As for the two sets of Dutra Duals, I bought one from Doug when he was still selling them. Then another set crossed my path for a good price and I grabbed those also. I've been known to rathole parts for future projects when I find them for cheap. (Hush up, @j par :poke:.)
 

j par

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Not really. A little more grunt for pulling power is what spurred this thread. I was OK with it as it ran, just figuring if it's in pieces there is no more trouble putting it back together with different parts instead of the same parts. And I already own all the parts, too. :D
A little more grunt for pulling power?..lol..
What in the heck are you planning to pull?...
Well thank goodness it's not your time, your money, your effort or your truck. I shall soldier on with my (sadly) steep learning curve. Besides, yours is already way nicer than this one will ever be, and that's with it still in a bunch of pieces in your garage.
Kudos to you for spending all that money and time for said results and not losing your bananas...
The V8 granny for speed two-wheel drive that I was referring to and comparing to your truck was a 1973 I had a couple years ago and I'm sure did a big thread on...
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A truck I bought for $700 probably put a few months of time in a couple k into and I drove it for a month while it drove absolutely perfect 70 down the freeway with one finger on the wheel it drove me absolutely bananas driving that Granny fout speed.. (I was making zero comparison nor did I mention my current truck...as there isn't any...)
And it made two dump runs already!
To drop off or pick up...lol..:poke:...
 
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