Guys with inline 6 engines...lets talk inside

[Tx Firefighter]

I want to hear from guys with 6 cylinder engines. I've had a bunch of stock ones, so I'm no newbie to them. I'm a member over at inliners too.

I have both a 250 and a 292 to build, not decided which yet. I already have an HEI and a set of headers for whichever engine I go with.

I want to hear what you have, how it works, any pain in the rear things about it, whatever.

What carbs, intakes, cams etc? Do they run well? Any drivability issues?

I see plenty of guys with 4 bbl carbs on these things. Tell me about yours. Linkage.... type of manifold....manifold heat....air cleaner....let's hear it.

Cams....

Exhausts.....mufflers...pipes....sound.....

Fuel mileage too....

I want to hear it all.

[Palf70Step]

My 70 is the original stock 250 for now. I have some headers and an HEI for it and I'm thinking about one of the Clifford 2 or 4 bbl intakes. I'm not sure which way to go with the carb since I don't plan on doing anything internal to it. Since it is only my toy, I kind of like the idea of the 6. and since I have no power nothing on it, it moves pretty good.

The 82's new style 250 was just put back together today. Hopefully it'll crank and go tomorrow. Except for the cherry bomb, that is the only plans for it.

[Gee_Emm]

I have a 250, I am planning on mostly stock, maybe some better stuff for the guts but I want it to look stock on the outside. Overslung aircleaner, it came with a HEI but I won't be able to use it because it interferes with the AC brackets so I will have to find some other type of electronic ignition that will fit in the dizzy.

I have driven it about 1/2 mile total reaching a blistering 5 mph and I didnt even make it out of first gear on the 3 speed so I have no idea how these 6's do. I am planning on run AC and PS on it, I just hope there is enough power left to turn the wheels :p

I found out tonight that they sure are alot easier to move around the yard then a big block.


Here is a pic of my intake, thats the most work I have done on it.

[Bryan68custom]

You might try these guy's (Kustom machine shop) they are local but used to run straight sixes in 67,68 camaros that would pull both front tires up on launch. I think Todd still has the 68 today it's just a little more docile. the # is 903-465-0918.

[Putter]

I have a 250 in my '69. Anything that breaks can be fixed on the side of the road. Plenty of room to SIT under the hood and work. Mine is a points-type system instead of HEI. That is my only big downfall. Single bbl Rochester with original sediment-bowl filter (forgive spelling). I have mixed emotions about keeping it. In the rural area outside of Jackson, I love it. I can stroll at 50 mph, and it is completely quiet and relaxing. In town however, trying to go 70+, it sounds like it will explode any second (3-speed saginaw).

[N2TRUX]

TX I'm no inliner, but I thought about you this weekend. I found a truck with an engine that you will appreciate....

[stickshift_or_walk]

If you want the last word on wringing horsepower out of Chevy inlines, you might want to talk to these guys.

Self Racing

They're about 3 hours north of you in Durant, OK - my home town. Glen (father) and Kevin (son) have forgotten more than most of us will ever know about the capability of these engines.

Oh yeah, they do V8's, too.

Kevin's headwork is legendary, and I recall the rail dragster they ran back when I was in high school - based on a 250, I believe, and it was running away from even big blocks. Power to weight ratio, does wonders.

You said you wanted to hear it all...

SSOW

[dubie]

looks like the inner fenders of a 55-59 there Ken got any pics of the rest of the truck?

[N2TRUX]

Originally Posted by dubie

looks like the inner fenders of a 55-59 there Ken got any pics of the rest of the truck?

I wish I did. It was a really nice white tri-five truck but I couldn't get a clean shot of it. I had planned to get back to it and never did....

[PICKMUP]

I hate to show this motor again-it is probably getting boring to most.
I started out with a stock 250, 4spd & 4:10 rear...just couldn't drive it on the highway.
So I put in a 700R4. That took care of highway speeds, but no power in OD.
So I put in a stock 292. That was starting to work...good pulling power.
So I added Offy intake, headers/duals, HEI & 390 Holley carb. Now that was starting to make some power and sounded great. Motor blew up.
So the next step is a built 292: ported, big valves, cam, balanced, etc. The only problem is time---or lack of time.

[Tx Firefighter]

See, I have been a member over at inliners for a long time now. I have Santucci's book, I have owned three trucks with 6 cylinders in them.

It's just that I've never hopped one up personally. I want to know how the seat of the pants difference is when you take off the factory intake and exhaust and replace them with good hi-po pieces.

I want to know what type of exhaust to use. What type of 4 bbl works best. What the slickest way to overcome the linkage issue is. How close the air cleaner gets to the brake booster....

[Tx Firefighter]

Frank, how's the drivability?

Is there any manifold heat?

How did you do the linkage?

What mileage did you get with the 292 and OD trans?

[beaterC10]

I used to own a 63 swb with a stock 292. I added a Clifford header with single exhaust. Using the header eliminates manifold heat, but even in Indiana winters I didn't have any issues. The truck was quick from a standing start but I seemed to run out of motor around 70mph. That was with the stock monojet and intake. The header seemed to pick up the gas mileage a couple mpg. The header was an easy install and fit well.

[inline6Bill]

Ran a '70 1/2 ton with a 292/4 speed combo. Miss that truck to this day, but here is the info about it you want to know.

Intake: I ran both the 4 bbl and a 3-1bbl manifold; the 3-1 bbl was a PITA to set up, but had MUCH BETTER performance and took care of a fuel distribution problem.

Exhaust: Ran a handmade set of headers with a dual exhaust. The engine sounded nice at idle, but when you got the RPM up it just sounded wicked.

The cam, heads, and rest of the engine was completely stock except for dress up items. This combo would get 20 mpg as long as I kept under 60 mph. If I was to do it again, I would swap in a Tremac 5 speed overdrive trans.

And yes, those 3 1bbls worked great in Oregon winters, and boy, did I get compliments from people for keeping the 6 and those 3 carbs.

[69_hafton]

Mine's still pretty stock engine-wise. Rebuilt the suspension and brakes
without any mods for now (did it when I was real poor, otherwise I'd have dropped it
with disks and more). Signature says most of it, and I'd like to think that I can
get to a point of putting on performance parts on it.

First thing I did was put on an HEI from a '79 or so six. Then came
redoing the intake and putting on a Holley rebuilt 1 bbl Carter Carb from
O'Reilly's. Power steering was a priority when I started driving the truck
daily. Still has the bi-metallic spring on the exhaust manifold. Next thing
in the works is a new process a833 transmission for driveability, we'll see
how it holds up to engine mod's later on. Probably will have to swap out the
rear 4.11 ring and pinion for a 3.70 or better. Want to do alot to it, but
am happy just to make progress here and there. Until the body work begins,
it's better just to be able to drive it.

292 engine pic

['68OrangeSunshine]

Hi Tex, I love the 292s, but never ran a 250. I hear they tach higher, but the 292 has torque like a bigblock. Anyway, the first time I rebuilt a 292 was in 1977, the only thing I did extra was bore .030 over. Later ('78) I added an Offy intake, 4Bbl [390] Holley, and Clifford headers. That engine lasted 25 years and about 250,000 miles.
I recently completed my next 292, and am about to break it in. This one was the original block from when I bought the ('68) truck used in '73. (When I rebuilt a '67 block, I put up the original in crates.) This next rebuild was also bored out .030 over, Badger pistons, orig rods, ARP fasteners, Crane cam, Rhoads lifters, 4-angle valve job on 1.84 [305 V8] valves, aluminum cam gear, hi-volume oil pump. The Holley got rebuilt (w50cc accelerator pump). The Offy intake was bead blasted clean and the Clifford headers were bead blasted and painted w/VHT cast iron gray. Ignition is stock right now, points on AC/Delco distributor, Mallory "Voltmaster" coil, Champion truck plugs. I have a 12" x 3" Moroso air cleaner with a K&N element on the Holley. With manual steering and standard (not power) brakes I have no clearance issues.
For an arid climate like Tucson, I don't need a "wet" intake -- but it does run better in hot weather, unlike V8s.
I used to have a rube-goldberg bellcrank '68-style throttle linkage. There were periodic problems. [Like no WOT] I have since gone to a '72-style gas pedal and aftermarket throttle cable. There are still drive-ability issues with getting used to the new set up, but it's less problematic than the rube-goldberg.
Also I went with a Centerforce II clutch but I'm having trouble getting the clutch to disengage.
After break-in I have a Pertronix Ignitor II to install on an Accel (NIB) blueprint points L6 distributor.

[Fred T]

You might want to go to www.myoldtruck.com and talk to streetroddertim. He has a 37 with a 250 that will outrun all but the hottest 350's.

From what I've learned over at the Stovebolt board most run a 500 cfm squarebore. The 390 just isn't enough carb. 292 seems to be the engine of choice for a driver due to the torque. Biggest problem with the engine is the air flow. If you really want serious power make a cross flow head from a pair of small block heads. Never seen one, but I have heard of a few. It is a lot of work, though.

From my experience, Texas is warm enough that you won't need manifold heat. If you were farther north, I would recommend using the water heat for the intake. It doesn't react as quick as the exhaust heat, but it's a lot better than nothing. There's a cavity in the bottom of some intakes that takes a cover plate for the water flow.

My friend has a 261 (earlier series truck engine) in his 52. Right now we have it around 300 hp, limited by the carbs. Dual Holley/Weber progressive two barrels (Pinto carbs). Our next project on it will be to rework the Offy intake to accept dual Rochester 2G's without adapters. Engine has a full race cam, shaved and ported head (we have a friend who ports racing heads for a living), Mallory Unilite dizzy, MSD-6 box and cast Fenton headers. With 3.90 gears he can burn the tires into 4th gear.

We prefer the cast headers, they don't have the heat radiation and rust problems like the tube headers do. They do usually require some grinding to fit with an intake.

A good source of parts and advice is Tom Langdon at www.stoveboltengineco.com , you probably know about him from the inliners board.

[smitty62]

If you're determined to do it, the 292 is the only way to go. BUT--be prepared to spend a LOT more money than you would on a nice 350. BTW--the manifold heat exchanger is not just for cold starts--it warms the intake so the fuel particles don't fall out of suspension in cool---(50-60 degree?) driving. Personally, I would never run an in-line without some sort of manifold heat regardless of where I lived. The fuel dropping out of suspension washes down cylinder walls contributing to cylinder wear and rapidly contaminates the oil--the General knew exactly what he was doing.

[shadetree]

Back to top, I love this thread! I wanna hear more!

[shortymac83]

Buddy of mine built the 250 in his 73 omega before throwing in a 455. He scrounged up a dirt track cylinder head and threw that on (sorry, no specs), 4 bbl intake with a Holley somewhere in the 350 CFM range, headers, dual exhaust, .030 overbore, 10:1 compression. I wish I could be of more help, but he just told me the basics and I'm planning on leaving my truck more or less stock. He said that with those parts and a hot cam, he got his car into the 13's with 4.11's in the pumpkin and a TH350 tranny...Seems a bit of a stretch, but what the hey...

[smitty62]

Although limited by cubic inches, I feel the 235 and the 261 engines are superior to the later 250 and 292 and IMO better looking.
There is also more aftermarket stuff available for them. If I can, I will attach a pic of my 235--of course boring a 261 engine to .060 over like my 235 would bring you very close to the 292 C.I. for the best of both worlds!

[Tx Firefighter]

Originally Posted by smitty62

Although limited by cubic inches, I feel the 235 and the 261 engines are superior to the later 250 and 292 and IMO better looking.
There is also more aftermarket stuff available for them. If I can, I will attach a pic of my 235--of course boring a 261 engine to .060 over like my 235 would bring you very close to the 292 C.I. for the best of both worlds!

Uh-Uh no way....

the later engines are way superior. They have much better oiling systems. They have individual light weight valve train rather than the rocker shaft stuff.

They have real rear main seals rather than rope ones. I could go on and on.

My 54 Chevy car had a 235 and I learned about them first hand. It now has a 350 V8 in it and I'm very happy.

Besides, I already have 2 of the later series 6 cylinder engines.

[Fred T]

The last of the 235/261 line had neoprene seals, but the newer line is a far better engine. Better oiling and cooling. Parts are easier to get, many interchange with the small block. Crank is balanced better.

Anyhow, here is a shot of Streetroddertim's 250.


He makes serious horsepower with that mill.

[arkracing]

http://www.cdpautomachine.com/ecatalog/powermanual.html
http://www.cdpautomachine.com/custca...s/dragcars.htm
That 50 Chevy was wrecked in a drag accident but they still have the motor and are working on getting it into another car.
2 SBC Aluminum heads with 1 cyl cut off each and then welded back together...is that awesome or what????!!!!!!

My 69 has a stock 250 in it with a 4sp on the floor...good power even with the 1 bbl - drove it from RI to Maine and got about 22mpg (not to shabby for a old junker) coming back it ran out of oil (i think it had a stuck ring) and didn't skip a beat - they are hard to blow up - even with no oil


Custom Design is in Connecticut - probably far away from you but they just did my 396 big block for my 33FordPickup
Awesome machine shop. and if you email Kenny or Ken Carlson - he'll be glad to give you some pointers on doing the 292