Inliners International Forums General Discussion Hi Performance New Guy Seeking Advice...

Greetings to all and sundry; I'm new to this board, and come seeking advice and information.

I'm currently just finishing up one project (a '67 Corvair with a 500 Cadillac in the back seat) and am starting the next project. That next project consists of a 1938 Dodge dump truck cab, which I will be planting on an ex-forest service '82 Chevy 1 ton dually flatbed chassis.

Since my wife and I plan to use the '38 as a tow vehicle, we intend to equip it for highway use pulling a heavy trailer with all pertinent comforts, e.g. air conditioning. I'm now in the process of slicing the '38 cab in half to lengthen it for a bit more interior room.

The '82 came with a 292 six which runs great; we drove it home from Colorado after our car was wrecked, but that is yet another story. Because we would like to be different, we intend to retain the six.

I figure that to serve as a good highway tow vehicle, we need 300 to 350 HP, and so had planned to build the engine as a basically stock unit with a turbo, similar TRowe's pretty powerplant. For this application, I expect that reliability is more important than acheiving every single horsepower.

Because the chassis short-geared (4.56, IIRC)we plan to replace the existing non-OD 4 speed with a hydraulic 700R4. Still, the engine will be running at fairly high RPM on a sustained basis. Would I be better off switching to a 250 crank? I won't really need huge torque as the 700R4 has such short first gear, as well as the final ratio being so short.

Whether 292 or 250, I know that I'll need good forged pistons; I haven't yet been able to find sources for same, and would appreciate pointers. Likewise, I'll probably go with good aftermarket forged rods, and again, guidance would be appreciated. Selecting the cam, the valve train, the degree of headwork, the compression ratio, and so on all need to be decided; likewise all such decisions lie far outside my experience.

Once stripping the Chevy cab off the chassis has been completed, I'll need to leave the engine in place for a while to help locate the transplant cab. This means that it will be a while before I need to begin engine rebuilding, but I would like to start the planning process. Some things, like mounting location for the intercooler will impact cab bodywork, and so must be preplanned.

Any and all thoughts and advice would be appreciated.

Oops...

Thats TLowe, not TRowe. I used to know a TRowe, hence the confusion.

doug, what gear ratio do you plan on running in the rear? mine with a 700r4 and 3.7 gears spins 2500 rpm @80mph. i also have a 27" tall tire. my engine idles and starts great also. i would suggest looking for some trw 2199f pistons. they are based on stock 292 design and are forged. they are built to take alot of abuse. they are also heavy! for a turbo leave the compression at the stock level, open the intake valves to 1.84 or 1.9, make them all good quality stainless also. my cam grind should work good also. you would want to limit boost while towing to a minimum, maybe configure a boost regulator for tow vs driving. the stock bottom end will be fine, since it won't get revved real high also, money saved. i would also reccomend the inline six power manual. it is available on this web site. lots of good reading on 292 stuff there. tom

Since it sounds like you want to add positive discplacement air and the 292 has a 4-1/8 stroke I would consider a turbo 400 and a Gear Vender OD unit with the stock style flatbed dually rear if it's in the 4.88 range especially it you plan on towing. 400's are pretty bullet proof especially with a lot of torque.

Turbos also cause a lot of heat under the cab over so you may consider a belt drive blower, ie: Whipple, Procharge, Paxton etc. A Clifford manifolds flows pretty well and have a low profile. A throttle body made of a Holley style carb plate would look great with electronic injectors or use the carb with a pressure top.

Dare to be different you said. Project sounds great. Good Luck

One thing nice about old trucks like this is the louvered hoods; heat doesn't build up like newer rides. The TH400 is great, as is the GV overdrive, but my preference would be a single piece unit like the 700R4. And yes, part of the reason is that I'm cheap. The 700R4 doesn't withstand tremendous torque well, but I'm not convinced that I need to develop all of that torque potential. (I just went through similar questions with the Cad 500; this is another long stroke engine.)

I do have the Leo Santucci book on hand, and yes, it is full of valuable information. TRW's website indicates that they no longer make engine componenets, so I assume that the 2199f pistons are vintage, but are probably findable in some warehouse. I looked up the Innovative Turbo exhaust manifold, and I'll probably go with that. I also like the notion of using multiport EFI.

By nature, I like the sound of a smallish, oversquare engine that happily buzzes up into the stratosphere. With the 4.56 axle and probably 31 inch tall tires, I've got plenty of leverage, and so may not need torque. Destroking the tall deck and building a long-rod rev engine would be my inclination. According to Santucci, this was the original method for getting more power from the 292 block until better rods became available, when all switched back to long-stroke designs for drag-racing torque.

The operative question then becomes go with my inclinations, or go with common sense? I would assume that a high-winder would work well with a 700R4 as it can downshift to give the leverage needed for high outputs, but still have overdrive for the bulk of the driving time at moderate output levels.

I'm not too worried about towing with excess boost; I wouldn't be pulling enough trailer to need high horsepower for long periods. Just the occasional blast to pass a foot-dragger or to get up a hill. More of an everyday automotive application than a semitruck application calling for massive horsepower for long periods.

So much for inclinations...

I did some research on the notion of building a long-rod engine. Using a 250 crank and 250 style pistons, one would need a 7.4 inch rod. After perusing the various manufacturers catalogs, the longest rods available are apparently 7.1 inches.

The Santucci book indicates that one of the disadvantages of the 292 piston is the overall length from the pin to the ring package, which leads to instability. One possibility, which I haven't yet looked into would be to use 250 style pistons in the 292, which would provide the some displacement, but a somewhat longer rod.

(According to my Grandfather's 1917 engineering books, if a pistons overall length is longer than the bore, it should properly be labelled as a plunger, not a piston.)

Whether any or all of this speculation will provide any real benefit remains to be seen.

special rods like that will cost close to 1k. i don't really think much is to be gained with doing the long rod setup in your application. the 292 is not a high reving motor, ussually 5k rpm or less. there is a rpm spot that causes lots of bad harmonics that occurs close to 5200-5400. can't explain all the reasons why, but it is the big stroke and long crank that cause it. tom

Thanks, Tom.

I guess after I get the engine apart and get an idea of how much overbore will be needed, I'll start the search for some 2199f plungers. I have seen forged H-beam rods for the 292 in one of the major vendors lists, and definitely want to go with the forged slugs.

I did pick up a pair of 700R4 transmissions this weekend, and I turned the wife loose with the plasma to cut the cab in half. Its now 21" longer, so despite just starting the project, we are actually making some progress.

sounds like a great tow rig.........

i'm not much of an engine builder, and my approach would be alittle different because of it.

i'd 1st do what was required to build the engine that developed the power/torque that i wanted in the most dependable way. Then chose a transmission, can't go wrong with a low'ish 1st geared overdrive in a tow-rig. Then chose the wheels/tire (diameter) and lastly select the gear ratio that would put my engine RPM's in the optimum range while at my intended highway MPH.

just my .02

After a bit more research, it appears that the useage of the 230 piston in combination with a 7 inch rod would be only .010 below the deck in a stock stroke 292. Since it will probably require at least a .010 cut to true up, this seems like it might be a decent start.

From everything I'm learning via internet searches, it appears that any forged piston for this engine is going to be a custom; even then, only Ross seems to recognize the existence of the inline 6. Any other guidance for piston sources? Any qualms about quality from Ross?

All of the above brainstorming is in pursuit of Leo Santucci's advice in his book about reducing rod/piston reciprocating mass.

52'F3...

The donor chassis is/was a complete and running '82 Chevy 1 ton. Driving 600 miles home suggested that an OD transmission would be a benefit, so we have opted to go with the 700R4. Like you mention, the lowest first gear in the business will also be a help getting the rig moving. The final drive is already fixed; I'm unwilling to change the gears on the Dana70 since it does work well as is, and I'm cheap, too.

My desire to devise a plan to reduce recip mass and raise RPM potential has little to do with drivability; it is simply the type of engine that I like. Because I'm planning on a Megasquirt injected turbocharged and intercooled engine, the forged pistons and the proposed H-beam rods are feel-good insurance.

Because the elasticity of my wallet has dimished over time, I'll probably wind up with a set-up very similar to TLowe's. But, one of the biggest joys in contemplating such projects is the ability to play what-if games. With that in mind, what else would be fun to think about doing?

Dear Doug;

You'll want to go ".060 over" on your 292 using Ross pistons creating the compression you want and just 'clean up' the deck.

That company (Ross) makes a precision product that's first rate.

You'll want to 'shot peen', polish and ballance the rods & crank too.

Just do it in stages as the money comes in and then you'll have the foundation for "what if".

Good luck.

The 700R4 will require some internal hard parts to be able to tow in OD this is not a complete list but will get you pointed in the right direction:

- HD wide band and new rev. drum
- Sonnax 2nd and 4th gear servos
- upgraded direct and 4th clutch packs
- upgraded front pump
- valve body upgrade
- .490 boost valve
- upgraded low/reverse boost valve
- beast shell

look up "patc.com" for parts - excellent people to work with.

Ross has always been a good supplier for 6's and avertises in the 12 Port News. But I have used Arias (where Ross came from) JE, Venolia along with Ross and never had a bad product. Arias has been the best for me and I believe it's because Nick Jr. has always has a soft spot for inlines especially GMC's
Rods are a different story completely. Last time I checked Carillos were over $2K and Cunninghams were just under that. These are for ones about 8" long. There are some off the shelf Olivers over 7-1/2" BBC's that have been made to work but I'm not for too much offset grinding of a crank.

Good luck, Still sounds like a great project...

1st let me say, that sounds like a really neat project. I hope it turns out well.

I am currently in the planning stages of a build (I have a 228 GMC, I may come up with a 270 or a 302) myself. I would like to boost it (I have some turbos and a blower). Unless I found a shelf stock piston that would work without modifying it (resize, fly cut, whatever) I would go custom anyway. Then again I am in Alaska and from what I've seen the machine shops charge more here. So any machine work to the piston (times 6) would likely offset the savings of a shelf stock piston VS custom.

As for brand I'm partial to Wiseco, that's why I'm a WD for them. Please don't misunderstand all of the brands mentioned previously definitely know how to make good pistons. I'm just speaking of my personal preference.

I've switched to Diamond pistons. Quality product. Since you are going to turbo you probably will want a flat or even dished piston, not one with a funky dome. To that end Diamond can build you a really nice piston in any bore size and pin / ring groove placement you desire.

Doug, I'd like to know what is happening on this project now. It's very much like what I'm planning. By the way,I was almost an Okie. I was conceived in Tulsa. Well, really I don't know what they were thinking about!

Doug, I was born in Miami, Ok, but have lived in Missouri since a year old. Like Beater of the Pack,I too, was wondering how your project is coming along? I too, am building a 302 GMC that will be turbo charged and efi using MS.

French does Diamond pistons have a web site?

Twisted - I'll check - I'm on my way home from New Zealand now so I will check when I arrive home - or just Google Diamond Racing Pistons - in the metro Detroit area.