The Stovebolt Site Forums The Shop Area Engine Shop New to inlines... Little help please

Ok so i was big into SBC for a long time. I do alot of turbo work on newer cars. Anyway. I have never really messed with inlines before. I have a 65 c10 that i pulled out the old 230 an put in a 250 out of a boat (it was free). I want to build the 230 and put back in the truck. In the men time. I need to do something with the 250 as i dont think its getting enough fuel. im running the old 1 barrel and intake/exhaust from the 230.

So what would be my best bet? intake carb header and HEI? what intake and carb would be best? I am thinking about building the 230 for a turbo and tbi. or blow through carb. But that might be next year some time. Any info and help would be great.
Thanks, Clay

the intake and exhaust are probably the same as on the 250. Go over to the inliners site, the guys over there are more into the high performance of the sixes.

The 250 responds pretty well to a few conventional go-fast tricks, cam, compression, and some moderate port and valve work. If you can get by without going to multiple carburetion, so much the better. While two or three carbs look sexy on a show truck, they're just twice or three times the trouble unless you plan to do nothing but run wide open all the time.

One sneaky trick is to replace the dish-top 250 pistons with flat-tops for a 307 V-8. They're the same bore size, weight, compression distance and wrist pin size, literally a drop-in swap. They raise the compression about one full ratio. Combining that swap with milling .050" off the head will get you another .25 ratio change or so. The ones I've built that way didn't need any milling for piston-to-valve clearance, But I didn't go radical on the camshaft timing or lift. If you decide to cam it up, by all means check for adequate valve clearance. There is a 4-barrel intake available, but don't go overboard on CFM capacity. Too big a carb will destroy the low end and midrange torque pretty decisively. There are split manifolds available for dual exhausts, which make it sound better, and might even gain a little HP at high speed. Nothing beats cubic inches, so a 292 is the best way to make an inline-six-powered Chevy turn some heads!
Jerry

I've had a 292 in my 53 1/2 ton with a 5 speed for over 20 years and putting my 2nd one in now. Never tricked it out.It always pulled my truck with ease and lots of power. Got 38MPG on the high way at 65MPH. Hotrod is right, the 292 is the one to fix up. Talked to some boys down south who race them all the time. They talk real good about them. There are some sights to go on on parts and how to trik them out. Keep em runnin
Steve

Well i like to go fast. My last car witch my wife is driving now. Is an 04 jetta 1.8t 5 speed that 300+whp and a blast to drive for a 4 cyl turbo car.

I really like the 250 and the old 230 really just needs rings (blow by). Like i said i really just want to get some better power out of her. Not looking to race shes just a daily driver.

Thanks for the info. Any info on cams and carb size?

Tommy is right the inliner site is where you will get help. I,m not shure, but I think there is something differant about those boat motors. That might be camed up.I think they put bigger carbs on them. There were 2 motors in most boats.

If you've got a Mercruiser engine, it's already got a pretty healthy cam in it. Some of them came equipped with Rochester 2-barrel carbs. I'm not sure if they used the flattop pistons or not, but it's a definite possibility. Did the engine happen to have that nice cast aluminum valve cover on it? Mercruiser engines usually had aluminum valve covers, and sometimes side covers, also.
Jerry

SPS said:
I've had a 292 in my 53 1/2 ton with a 5 speed for over 20 years and putting my 2nd one in now. Never tricked it out.It always pulled my truck with ease and lots of power. Got 38MPG on the high way at 65MPH.

Wow! My 66 chev had a 292 & 4 spd which seemed at the time like a wonderful highway truck. Plenty of power, great for towing trailers full of firewood etc, but I never got more than 12-14 mpg with it. I thought at the time that if that engine died, that I'd get better mileage with a V-8 & have more power. What other items are people adding (in addition to 5 spd transmissions) to beat the 20mpg mark? Are other people out there actually getting 20+ mpg with these 1960's 292's?

I'm sorry. I just don't see a 292 Chevy 6 getting that kind of mileage on gasoline. I don't really see them getting 20+ either. So I would be extremely interested in knowing how you did that. Would make driving these old beast even nicer.

38 MPG? I can't get but 32 in my little bitty toyota MADE for economy. I'm not saying you don't get 38 MPG, but I would need to see this to believe it. If you truly do get 38MPG, don't let the oil companies find out they will put you on a list.

38 MPG - astounding.

I've got a GEO Metro with a 1-liter 3-cylinder. It struggles to get 35 MPG on the interstate, and it weighs about half what a stovebolt does.
Jerry

I did a little trick to my carbrater. It's realy simple. But the 5th gear and auto trany rear is the other part of it. Rear is out of a 69 van so its 6 lug, I think it is 3:73 0r 3:55. The old ford Falcons could get 30 mpg in the 60's with there straight 6. I had one.

The Japs have made high mpg engines since ww2. There have been cars that have got 50 plus, but we all know why this stuf is not around. Hotrod if you like I could PM you some details on the carb. Now it is all fuel injected, the trick can't work om those but I never realy tried it out on one.

I get 73 mpg with my J. C. Whitney tornado carburetor insert.

sps is correct about the old Falcons, I had a '62 about ten years ago that was getting way over 30 miles to the gallon. I used to worry that the gas would go bad before I could use it all.

I think part of keeping these old trucks on the road is keeping the fuel consumption as low as we can. It's hard to use a stovebolt as a daily driver if you're only getting 10 or 12 miles to the gallon.

sps, if you have a simple trick that would help us get better gas mileage, I think we would all like to here it. It might get some of our old trucks out of the garage and back on the road.

I Went 91 miles the other day in my old truck pulling a 16' trailer loaded. Got about 13mpg with the 261 six that's in it.

Without the trailer and empty the truck last averaged about 16.

Can't complain too much about that. But if there is a trick to get more mileage, I'll take it.

I think panic has the better trick. He is getting two times what I'm getting. I don't mind sharing the trick. It is simple, With some small hose and a 1/4 " valve you can buy at a hardware store, you pull a little vacum off your float bowl vent. You get a little hesitation on the start, but hardly noticable. I just crack the valve a 1/2 turn or less. It might be differant with others. Make sure to have the air cleaner on when you set it. {I drilled a small hole under mine.} The vacum can be pulled from any outlet. If your not using your vacum wipers, thats perfect. Set it at idle, if you stall you've gone to far. I have mine in my cab. It makes it a little easier to set and fine tune.

So, sps, what you're saying is that you've introduced a variable vacuum leak?? I don't understand the "pull a little vacum off your float bowl vent" statement. Then later, "vacum can be pulled from any outlet".
I dunno...there's only so many btu's in a gallon of gasoline: energy is energy, power is power, and work is work. They're all physically and mathematically related. Unless your vacuum pulling magically increases the efficiency of the combustion process 50% or more, it just doesn't add up.

cm

There's a simple way to get good gas mileage on the internet, and I believe Panic has discovered the secret- - - - -lie about it! Good show, buddy!

Jerry

If anyone can ever document 38 mpg with any Chevy six cylinder inline engine they could be wealthy within a short period of time by selling the secret. Sorry, I can't see it happening. Maybe coasting down a 38 mile hill with the engine idling?

Engine off maybe while coasting.

Does anyone remember a movie where Dad (Walter Matthau) and son drive their neighbor crazy?
Neighbor is bragging about his mileage, and they're sick of it. They sneak into his garage and add 1 gallon of gas. Next day, neighbor reports he's getting 63 mpg!
After a week or 2, they switch off and siphon off a gallon of gas. Neighbor is now getting 7 mpg, and is now sure his car is dying and rushes back to the dealer etc.

I remember that sketch but I don't remember it being Walter.

A sketch like this was done on "Gomer Pyle USMC".

I'm not sure why this works, but it does for me. The vac is variable but when set it is fixed. As for the outlet, that is regulated by the valve. I found this back in the mid 80's. I'm also checking up on Panics find. It seems a lot simpler. I agree with you Hotrod. I might try using both together and see how that works. So far, Tornado looks pretty good. I'm all about learning new things. Keep an open mind. Your never to old to learn something new. I'm rebuilding my truck now. I've had it for 30 years and drove it every day up to 1990. I'm doing a frame off restore. Should be on the road by the spring. I'll post in engine shop my findings then. If I can, I'll try to digg up the ref. I have on the subject, so all can reserch it.