Straight sixes and fuel economy

[tarussell]

Has anyone had a "six" backed by an OD tranny?

I got a Cummins backed by a six-speed O.D. tranny , does that count ?

Tom

 

[jonrpick]

why not a 4.8 then? im gettin 21 on they highway with mine, and can smoke the tires from a dead stop,all stock. but also am i forgeting something or missed it already, but nobody has mentioned gearing. i have heard a lot of talk about 292's in work trucks hauling more than 350's in burbs and blazers, now i know work trucks are LWB and not a good comparison to k5's but people also forget to check what gearing you have. for example i have a 68 2wd LWB chevy with a 292/sm465/eaton rear end (dont know the name of the diff) with 4:56 gears and it will pull the house off the foundation if i wanted it to, but my 350/sm465/208/3:73's in my 10 bolt wont pull half of what that truck will. so i guess when comparing trucks, make shure the gearing is involved because lots of times to make up for the small motor, GM will stick steeper gears in them.

Another good point. Didn't most 292's come in 3/4 ton trucks and bread vans? I can easily see where a stock 292 through 4.56 gears and stock tire sizes would run out of breath pretty quickly--especially on the interstate.

 

[jonrpick]

I got a Cummins backed by a six-speed O.D. tranny , does that count ?

Tom

Heh... I wanna see that! Is that project still on hold?

 

[tarussell]

Heh... I wanna see that! Is that project still on hold?

Actually I was talking about my pull truck ( see signature ) .

The Blazer has got a 4-spd in it . All I need is time and money to get it done , and I just can't seem to get enough of each of them lately .

Tom

 

[jonrpick]

That head is way cool but as you said it ain't cheap ! Also you are on your own for an iintake and injection system.

I have driven a few Ford FI 300 c.i. with O/D tranny's . Most of them really were fairly lame do to the axle gearing ( 3.00:1 ) and 31" tall tires. Gear any motor to be happy at cruise RPM's and it will respond well - it's all about using the power band of the motor and the effectiveness of the gear used.

Since this is a play/project motor for you I would not waist much time/effort on a stock build - you might be dissapointed in stock form. Usually they have to be tweaked to make them fun - and that always cost more money .......

Tom

That head is made by Sissell Automotive. They've got a matching intake setup for it, and I believe Weber DCOE's will bolts right onto the head. It's pretty slick!

I totally agree with what you said about gearing and such. Any engine, small block, big block, diesel, could be a racetrack terror or a real dog depending on how it's built and which parts you compliment it with (gears, tranny, tires, etc).

 

[tarussell]

I did not know that Sissell made an intake as well - cool ! Still it's way out of my budget , but it would be fun .....

Tom

 

[jonrpick]

I did not know that Sissell made an intake as well - cool ! Still it's way out of my budget , but it would be fun .....

Tom

Check out the head... it's a beaut!

http://www.sissellsautomotive.com/cylinderheads.html

Click on the more pics link...totally worth it for the drool factor.

Here's the intake setups:

http://www.sissellsautomotive.com/fuelinjection.html

This is a complete motor with their head on it (top set of pics--bottom set uses stock head)

http://www.sissellsautomotive.com/completeengines.html

 

[tarussell]

That's cool ! I was aware of Sissells head but not the intakes.
Makes my old TBI junk just seem lame !

 

[dontoe]

My DD for the last year plus has been my '74 C-10 with a 250 inline six, 70,000 miles on it, one owner, kinda. It gets 17 mpg with the HEI dizzy and wider gapped plugs as the only upgrade. Great around town or for parts runs, but not a powerhouse on Interstate. I love the sound and torque.

 

[jonrpick]

That's cool ! I was aware of Sissells head but not the intakes.
Makes my old TBI junk just seem lame !

Yeah!! I must say though, for that much money, you'd think you'd at least get a cross-flow head.

I am thinking about building a hybrid head as seen in Leo Santucci's book, except I'd probably use two of the Mercruiser 4cyl heads instead of the V8 heads. They're cross-flow, with non-siamesed ports, but they use the stock bolt pattern (it was Mercruiser's improved design of the 4cyl GM head) and therefore wouldn't require modding the block.

That would let me do a MPFI setup.

 

[jonrpick]

My DD for the last year plus has been my '74 C-10 with a 250 inline six, 70,000 miles on it, one owner, kinda. It gets 17 mpg with the HEI dizzy and wider gapped plugs as the only upgrade. Great around town or for parts runs, but not a powerhouse on Interstate. I love the sound and torque.

Nice! We need to have a "Six Gunners" club on here! Can't wait to get my L6!

 

[colbystephens]

well, i haven't read the whole thread yet, so perhaps someone mentioned this already.

just because it may be a torque monster doesn't mean that it's fast or super powerful. horsepower is something like 550lbft of torque per second, so for the engine to be powerful, it needs to be able to produce HUGE amounts of torque persecond. so, to have a powerful engine you need to be able to produce huge power very quickly.

thus, horsepower is very critical in a tow-rig. huge amounts of low end torque will get you anywhere, but it may be at the pace of a turtle.

 

[jonrpick]

well, i haven't read the whole thread yet, so perhaps someone mentioned this already.

just because it may be a torque monster doesn't mean that it's fast or super powerful. horsepower is something like 550lbft of torque per second, so for the engine to be powerful, it needs to be able to produce HUGE amounts of torque persecond. so, to have a powerful engine you need to be able to produce huge power very quickly.

thus, horsepower is very critical in a tow-rig. huge amounts of low end torque will get you anywhere, but it may be at the pace of a turtle.

I hear ya... I still plan to build one to rev higher and breathe better when doing so.

I don't know why I'm so intrigued by the design of those things.

 

[kirkallen143]

Want to overcome the V8 blues? I have a turbocharged inline 6, it is the small Ford 200. Even though it is in an early bronco, same principle though, it can pretty much beat any stock/mild built 289/302/351. And they say you will never go fast with that six, well I showed them in the sand drags. I can also still pull my 18' boat behind it too and not worry about a thing, either.

On the fuel economy side, I am getting @ 15mpg w/ 33" BFGs and 4.10 gears w/ a np435, if I keep my foot out of it (hard to do though, boost is an addicting drug).




Have a good one,
Kirk
ps. sorry about the ford hijack.

 

[Jrgunn5150]

For daily fuel economy, I drive a 91 Integra, cost to me was free, and it get's over 30 mpg.

 

[jonrpick]

Want to overcome the V8 blues? I have a turbocharged inline 6, it is the small Ford 200. Even though it is in an early bronco, same principle though, it can pretty much beat any stock/mild built 289/302/351. And they say you will never go fast with that six, well I showed them in the sand drags. I can also still pull my 18' boat behind it too and not worry about a thing, either.

On the fuel economy side, I am getting @ 15mpg w/ 33" BFGs and 4.10 gears w/ a np435, if I keep my foot out of it (hard to do though, boost is an addicting drug).




Have a good one,
Kirk
ps. sorry about the ford hijack.

Ha! The highjack is welcomed in this thread! It's relevant info anyway.

Going forced induction is a very real possibility. I know that there's nothing about straight-sixes in general that would keep them from being performance machines. The 292's head sucks, but that can be overcome.

I assume most of the negative talk I see about 292's stems from them being in a 100% stock state, stock cam, no headwork, and a single 1bbl carb. Not exactly a recipe for tire-smoking.

Knowing that folks drag race with sixes and are making power well in excess of some milder SBC's tells me that a lot more is possible than what GM engineered into a stock 3/4 truck.

 

[vortec]

Could even swap in a Syclone/Typhoon 4.3L. I've been told they make pretty good power

gm underrated them at 280hp. they are turbocharged, so that adds complexity and cost, and the parts are getting harder to find, for obvious reasons.

From what I recall, the Vortec heads actually first appeared on the 4.3, so fairly very early on (well before 1996) they may already have had those heads. May account for why they feel so strong compared to similar older vintages of 350.

according to a few chevy ads i've seen, the 4.3 was introduced in '84 as a vortec motor. gm played around with them quite a bit. early ones had carbs. the power numbers have varied, even in the same year. i have an optional 200hp/260tq version in my 94 c1500, but the normal one for that year was 165/240 (i may be a bit off), like my friend's 92 had. another friend had a 93 s10 blazer with a 160hp 4.3, and her parents had the exact same vehicle, but with a 200hp cpi version.

 

[dontoe]

For daily fuel economy, I drive a 91 Integra, cost to me was free, and it get's over 30 mpg.

But does it have the "class" of a '74 Stepside?

 

[jonrpick]

But does it have the "class" of a '74 Stepside?

Does anything?

 

[Jrgunn5150]

No, of course not. But it does have the "I don't care if you hit me" effect on me, which makes me a much calmer driver out here in SoCal.