SB towing engine thoughts... CARB HELP

Posted By: HotRodDave

SB towing engine thoughts... CARB HELP - 01/15/15 10:16 PM

Got a customer who had to sell his cummins and wants a motor in his 85 to perform similar and here is what I got coming to gether, what do you guys think?

340 block 4.070
4 inch stroke
.512 lift [Email]230@.050[/Email] single pattern lunati hydro flat tappet
R/T magnum heads, lightly ported
Eddy RPM intake
650 Thunderseries Eddy
1 /5/8 summit brand headers
Mahle pistons (really nice light weight, hard anodized teflon skirts!)
Stock worked rods with ARP bolts
9.3 compression
.040 quench but it is a smaller area than I like.

Anything I am missing or doing wrong?

Stock 12V cummins is what 190 HP 400 TQ? I am hoping to make 300HP and 500TQ at a low RPM range. Truck has 3.55s and 727 4x4.

Posted By: aspenrt360

Re: SB towing engine thoughts... - 01/15/15 10:19 PM

sounds like a torque beast to me.

Posted By: MR_P_BODY

Re: SB towing engine thoughts... - 01/15/15 10:26 PM

Quote:

Got a customer who had to sell his cummins and wants a motor in his 85 to perform similar and here is what I got coming to gether, what do you guys think?

340 block 4.070
4 inch stroke
.512 lift [Email]230@.050[/Email] single pattern lunati hydro flat tappet
R/T magnum heads, lightly ported
Eddy RPM intake
650 Thunderseries Eddy
1 /5/8 summit brand headers
Mahle pistons (really nice light weight, hard anodized teflon skirts!)
Stock worked rods with ARP bolts
9.3 compression
.040 quench but it is a smaller area than I like.

Anything I am missing or doing wrong?

Stock 12V cummins is what 190 HP 400 TQ? I am hoping to make 300HP and 500TQ at a low RPM range. Truck has 3.55s and 727 4x4.

You cant compare the torque of the Cummins with that
of the gas burner... the one is doing it at about
1000 rpms vs we will say 3800... will the gas burner
fit the bill... it might DEPENDING on the load and
if the conv is right

Posted By: WO23Coronet

Re: SB towing engine thoughts... - 01/15/15 10:30 PM

That sounds more like 400+HP to me, wouldn't 230@.050 be a little big for a towing engine? Other than that it looks good to me

Posted By: MR_P_BODY

Re: SB towing engine thoughts... - 01/15/15 10:34 PM

Quote:

That sounds more like 400+HP to me, wouldn't [Email]230@.050[/Email] be a little big for a towing engine? Other than that it looks good to me

Not really.. the stroker will eat up some of that
duration

Posted By: HotRodDave

Re: SB towing engine thoughts... - 01/15/15 10:41 PM

Not too late to go one size smaller on the cam if it would be better

I don;t think it would have too much cylinder pressure.

Posted By: Streetwize

Re: SB towing engine thoughts... - 01/15/15 10:49 PM

For towing I might think something around 224 @.050 with that head should work well. Keep it a fat mild ramp with a relatively mild spring and let the crank arm do the work. I still like a fairly tight centerline so the torque comes on hard for inclines, etc. Something like the old Isky or Lunati 4x4 grinds would work well. Lunati used to have a 228/235 Truck cam that was pretty stout for a 360 but would be about as aggressive as I would go for that combo, it's got to be able to pull a tight converter out of the basement.

Posted By: HotRodDave

Re: SB towing engine thoughts... - 01/15/15 11:10 PM

I also have a 218@.050 .488 single pattern cam I could use.

I can't find the Dunnuck 440 towing build, wanted to read that again, anyone save it?

Posted By: Grizzly

Re: SB towing engine thoughts... - 01/15/15 11:17 PM

Quote:

Anything I am missing or doing wrong?

A T3 turbo.

Posted By: Dunnuck Racing

Re: SB towing engine thoughts... - 01/15/15 11:18 PM

Dave, that 440 used a Lunati Street master can, 225/225 @ ,050 477/477 lift on a 108 lsa
Should work well with a 4" stroke small block too.
Keith

Posted By: HotRodDave

Re: SB towing engine thoughts... - 01/15/15 11:25 PM

Do you have the dyno sheet or a link to the other thread?

Posted By: dogdays

Re: SB towing engine thoughts... - 01/15/15 11:29 PM

:

Magnum heads, use a single pattern cam.

For low end torque, a tight LSA helps, especially if one chooses shorter durations.

I think your cam choice is one or two steps too big. But looking at some dyno tests muddied the water. You may be at exactly the right place.

Diesel torque curves have a different shape. Peak torque may be equal, but at lower rpm the Diesel should be way ahead. For example, this link gives you an idea. The 12-valve manual trans engine of the '90s had 320 lb-ft of torque at 500 rpm.
http://dodgeram.org/tech/dsl/Facts/96specs.html

R.

Posted By: DaytonaTurbo

Re: SB towing engine thoughts... - 01/16/15 05:57 PM

Too much cam and that intake has too much runner volume for a dedicated tow rig IMO.

Posted By: Challenger 1

Re: SB towing engine thoughts... - 01/16/15 06:17 PM

Quote:

Got a customer who had to sell his cummins and wants a motor in his 85 to perform similar and here is what I got coming to gether, what do you guys think?

340 block 4.070
4 inch stroke
.512 lift [Email]230@.050[/Email] single pattern lunati hydro flat tappet
R/T magnum heads, lightly ported
Eddy RPM intake
650 Thunderseries Eddy
1 /5/8 summit brand headers
Mahle pistons (really nice light weight, hard anodized teflon skirts!)
Stock worked rods with ARP bolts
9.3 compression
.040 quench but it is a smaller area than I like.

Anything I am missing or doing wrong?

Stock 12V cummins is what 190 HP 400 TQ? I am hoping to make 300HP and 500TQ at a low RPM range. Truck has 3.55s and 727 4x4.

I don't think a sb anything is going to proform similar to a diesel. No way no how and I wouldn't consider any sb for towing. My

I burned up a 360 motor(burnt 3 valves) towing a 26' enclosed trailer through the wimpy smokey mountains back in 1990. That was the last time I towed with a sb.

Posted By: d100dragracer

Re: SB towing engine thoughts... - 01/16/15 06:35 PM

I think the cam is pretty close myself with a 4 inch crank I would not use that 218 duration if it and the 230 were my two choices much smaller it will be out of breath before it reaches much rpm I realize its being built to tow with but it wont be towing all the time more than likely plus it will still have plenty of torque to get going not like a Cummins does but when its rolling good I would think it would give a older Cummins all it wanted as far as passing someone rolling at say 55-60 mph. I have owned a older Cummins good tow rig plenty on the bottom but not a speed demon when it was rolling good that 4 inch crank makes a huge difference in a small block. You should have over 400HP I would think and close to 500 ft lbs on the torque maybe a little short of that but I would say close.
A 4 inch stroke small block tows just fine in my opinion hell it has more stroke than a stock big block 440 has and they use to be the rave supposedly for towing before all the diesels came along I think we have got a little spoiled with the power the diesels are making now but it sure doesn't mean that a 4 inch small block cant still get the job done I assure you it will if it has a good cooling system.

Posted By: HotRodDave

Re: SB towing engine thoughts... - 01/16/15 09:41 PM

He pretty much ALWAYS has a 16 ft trailer with a small bob cat hooked up to it.

A 12 valve cummins is $3500 just for the motor not to mention the cost of the conversion (trans, exhaust, fuel system...)or the fuel that is almost %50 more $ now so we are just trying to do the best we can with what we have.

If the intake is a real question I do have a regular performer butt I was figuring with converter slipage that any more TQ below 2000 will never be used.

He has mentioned that down the road he may get some 1.7 roller rockers to replace the stock 1.6 magnums we are going to use so he may get a little more lift out of it yet.

The motor he was running the last two years in it was a JY 5.9 with a ring job, a couple cylinders had a little excesive taper, slightly ported factory magnum heads, air gap, same carb, exhaust, under 9.0 compression, no quench, the cam in it was a 222@.050 .540 lift roller but every couple months it would poke a hole through a stock rocker. Him and his buddy built it and it is ready to get rebuilt again. It was barely adequate. I would have tried pushing a 440 on him but then he still has to change a bunch of crap and push the cost up too high and a 340 stroker will hold more re-sale value if he can ever get back to a cummins truck.

Posted By: 340Cuda

Re: SB towing engine thoughts... - 01/17/15 07:36 PM

I towed with a 1980 Dodge 1 ton that I had purchased new for many years.

It had a tow package with a HD 360 which included exhaust valve rotaters etc. It was still very hard on exhaust valves so I would keep that in mind when doing the heads and not skimp in that area.

Bill

Posted By: HotRodDave

Re: SB towing engine thoughts... - 01/30/15 07:21 PM

Quote:

Quote:

Anything I am missing or doing wrong?

A T3 turbo.

But that would not be the way the factory did it

Posted By: Crizila

Re: SB towing engine thoughts... - 01/31/15 12:40 AM

Maybe a smidgeon less duration. Otherwise, I like it. If he is towing under 10K gcw, should be just fine.

Posted By: dvw

Re: SB towing engine thoughts... - 01/31/15 12:46 AM

My old 360 1/2 ton had a stock intake, t-quad, and a Summit 214@.050 cam,3.23 it was pretty decent. The next 1/2 ton I replaced the 318 with a stock 5.9 Magnum with a Mopar Performance dual plane in place of the EFI,600 Holley, headers, and a 3.91 gear. It was very good except stopping.
Doug

Posted By: Grizzly

Re: SB towing engine thoughts... - 01/31/15 08:31 PM

Quote:

Quote:

Quote:

Anything I am missing or doing wrong?

A T3 turbo.

But that would not be the way the factory did it

Well, that's how Ford does it with a twin-turbo six, and that's factory isn't it?

You can stroke and poke, port and polish, and put whatever cam you like in it and you'll never get a torque curve like the boosted six above.

You don't have a sniff of what you are up against with an ISB Cummins, do you? That's a work machine, not some toy. The ISB makes more torque at 1300rpm than you will at 3500 rpm. Like others are trying to tell you on here, don't even try to compete with one. How long do you think your combo is going to last with a Bobcat hooked to it "always" as you put it? Since you are digging up replys from 2 weeks ago, maybe go back and read Challenger1's post while you are at it.

Your customer would be better off picking up this $750.00 V10 out of the used section on here and do a full swap. Everything is there, and it's one of the few gas engines made to pull things like his Bobcat that won't wind up cooked on the side of the road.

Factory, right?

You're welcome.

Posted By: DaytonaTurbo

Re: SB towing engine thoughts... - 01/31/15 09:57 PM

OP claimed the junkyard 5.9 was barely adequate. With a stroker upgrade, some more compression and quench he should easily move from the barely adequate category into the acceptable zone. FWIW I see a lot of guys hauling bobcats around with half tons, but here our roads are long and flat.

Posted By: SNK-EYZ

Re: SB towing engine thoughts... - 01/31/15 10:17 PM

Quote:

OP claimed the junkyard 5.9 was barely adequate. With a stroker upgrade, some more compression and quench he should easily move from the barely adequate category into the acceptable zone. FWIW I see a lot of guys hauling bobcats around with half tons, but here our roads are long and flat.

Anyone hauling a bobcat on a trailer behind a half ton truck is using way to small of a tow vehicle.

It's not just pulling power that need to be thought about you need at least a 3/4 ton truck to have adequate brakes to stop something that heavy (even with trailer brakes).

Posted By: HotRodDave

Re: SB towing engine thoughts... - 01/31/15 10:50 PM

A 97 12 valve made 440 TQ @ 1500 RPM. I don't see why that is un reasonable to expect that at a little higher RPM, not like you could even use that TQ at 1500 because the converter stalls more like 2000.

BTW I have 2 V10s complete sitting in my shop ready for swaps, he did not like the mpg of the one he had. No reason I could not coax more MPG out of this engine when un-sadled from emmisions controls allowing more compression, better cam and I can run tighter quench a better flowing exhaust, less friction and one day when he can afford another cummins this motor will make a good swap (with a bigger cam)into a 68-69 dart.

BTW we are swapping a Dana 70 and bigger leafs and over loads. We are looking for a 3/4 4x4 front, the matching one for the rear has the driveshaft on the oposite side meaning more work than I want to fool with.

Posted By: upnover

Re: SB towing engine thoughts... - 02/01/15 03:54 AM

you cant touch the towing ability or mileage of a diesel, no way no how. if he doesent like the mpg of a v10 wait til he sees the mpg from a smallblock trying to haul a bobcat. look at a 4bt (4cyl cummins) from a breadtruck. you can also pick up school busses that have cummins and Allison auto's with maintenance history for 4k here anyway, pull what you need and scrap the rest to recoup some of your $

Posted By: d-150

Re: SB towing engine thoughts... - 02/01/15 04:48 AM

v-10 likes gas ,but that stroker is really gonna like gas

Posted By: Leon441

Re: SB towing engine thoughts... - 02/01/15 04:29 PM

I like what you are trying to do. You will need extreme cooling measures to the engine and torque converter. Sounds like the haters are not seeing the potential of torque with RPM.

I've owned a V10 pulled like crazy right off the bump. That you can get with a sb stroker. 8mpg towing big enclosed when you kept it under 60. Towed with 360 blew it up screaming it up a hill. My 440 puuled great with the right combo. Got rid of it only because the truck was a rust bucket.

I love my diesel but writing on boost and maintenance is a shortcoming. Overall you can't beat the million mile engine. But, I think a stroker small block can do the job. Many small blocks did it for years. I would highly recommend Doug thorley tri-Y headers. Huge difference on the 440.

Posted By: HotRodDave

Re: SB towing engine thoughts... - 02/14/15 06:51 AM

So it is running, pulls like a freight train when the carb is co-operating, we are trying to use his 650 Thunder-series AVS but it was very lean and put the biggest jets and smallest rods we could find in it and it is still lean but all the bogging is gone. We tried a friends 650 double pumper and it really woke up so now he wants to get a new carb, looking at this one for the tunability and a little more air than the 650 for a few more RPM.

http://www.summitracing.com/parts/qft-ss-750-an/overview/

What do you guys think?

Ended up a hair under 10 to 1. 218@.050 109 LSA, R/T heads cleaned up a little, cheapy headers dual 2.5 exhaust. .031 quench, 416 cubes. It seems to pull a lot harder with a 1 inch open spacer.