The Stovebolt Site Forums The Shop Area Engine Shop Is a 350 enough ?

I had a 350 that blew in my bus. Please don,t ask. Long story. Just curious that when this is a motorhome and fully loaded. Its a 22 foot Bluebird. GVW is 22,000 lbs. Should I go with a bigger engine ? I live in the rockies. Thanx. Cheerz !

Find a DURAMAX with an ALLISON transmission. That will pull it.

Loaded question. A stock 350 carries anywhere for 145HP to 600HP. If you have the right combination setup for low end, sure, a 350 is fine, but a 454 with a mild cam is better. I own a Durmax myself, and that is the answer, but probably not conducive to your application.

Your easiest solution would be to have the right engine builder get the right valvetrain setup for haulin for you for a 350. Probably the cheapest too. Next best bet, I'd shoot for a 454 with a cam setup.

I don't think an Duramax swap is realistic. It's drive by wire, fuel coolers, intercoolers, fuel tank swaps, etc. Too much money. Just sell the motorhome and buy something with a diesel if that's what you want.

If you're in the rockies, gearing makes a big difference as well without doing anything with the engine too.

GVW or GVWR is 22,000?

There is a lot of it depends in answering a question like this, but I'm going to come down on the side that says no. You need more torque at lower speeds than a small block is going to make withut spending more money than a bigger motor would require.

The conventional answer is Diesel, but I'd go witha BBC or a 500 Cadillac.

How fast do you want to climb those hills? How much are you really hauling? What tires sizes and gear ratios are you running? All these things need to be coordinated.

How much are you going to drive it and how long do you plan to keep it? Those answers go a long way toward answering the Gas versus Diesel question. Diesel conversions usually cost more but if you are into this long enough they can pay off.

When in mountains, there is no replacement for displacement. I would look for a big block. A stock 454 will play where a 350 has to work its guts out.

Just remember that those mountains used to be handled by an old 235 or 261. A lot of people in the auto hobby suffer from "if it's bigger it's better" disease. Not that it is a bad thing but there are folks who would say if you had an 800 cu inch Buda it was too small. A good running 350 should do fine for the average guy. Remember also that well respected auto engineers put that engine in there in the first place. Give it a chance.

Another possibility is a 383 cu. Stroker motor.
From what I can gather they are a good compromise as they produce plenty of torque without the BIG BLOCK size,weight and (lack of) economy.
Just my 0.02c.

Everyone has a good point, and as Dave says "Give it a chance". A lot of school buses and trucks have been built and sold with a 350 motor and serviced the owners needs for a long time. Yes, it may be slower and you might have to downshift more to get where your going. Are you going to drive it enough to justify a bigger engine and all the stuff do make it work? My Dad had a '81 C50 Chevrolet with a 16" stake rack that I drove lots. It had a 350 2 barrel with a 4 speed, 5:83 rear end, 7:50 X 20 tires. It would go loaded (20,000#) 50 -55 all day, 40 at the top of hills in 3rd gear. But it went for 7 years without major trouble. Don

I personally would put in a Cummins ISB with the appropriate RD option (from a delivery truck, etc) and go that route. 2-valves are lever actuated throttle. All 4-valve engines are drive by wire, however there is a cable going from the pedal to a spring that actuates an inexpensive throttle position sensor ($20 at your FLAPS) same setup on the Isuzu engine (Duramax) or a Navistar engine (Power Stroke)

If you want to keep it petrol, follow Jock's suggestion. A 383 stroker can be made for $2500 with great torque and plenty of top end by starting with a Vortec block and heads and an engine kit - plus you can build it to run on cheep pump gas.

I would go with the 383 since they are good engines where a 350 is to weak and a 454 is to big. just make sure you find a block with four bolt mains not the regular 2 bolts. The extra torque the 383 makes breaks the main caps off and throws the crank. I have seen the aftermath of that in a 80's camero that was converted to a 383 on a two bolt main what a mess.

As for diesel. Easiest would be to go to a 6.2 or a 6.5 turbo chev block as they mount to the same trans as a 350 and the basic computer of the 6.5 turbo would be a easy swap for you.

The Isuzu engine is good until you need injection work and then they never stop leaking and if you have bio diesel, don't run it cause it will mess up your injectors. Navistar engines weigh a great deal more then the GMC diesels and the Cummins, Also the related recals on the 7.3l and a 6.0l isn't worth anyones time since they blow turbos like kids eat candy. the Cummins ISB 5.9L engine is used in everything from the Dodge Pick up to some class 7 trucks so parts are easy to get.

Cost has to be taken into consideration a Cummins diesel from a wreaker can cost around $6000-8000 a navistar about $4500-7000 a GMC well that varies region to region but they can still go for around $5000. Correct my pricing if I am wrong it has been a while since I looked at smaller diesel pricing.

GM's Goodwrench engines have a 350 replacement engine called medium duty. It is a replacement for 350 engines in 1 1/2 & 2 ton trucks. It is high torque & built rugged.

383 all built with low end torque in mind. A 454 would be nice, but you will run into installation issues. The factory sent it out with a 350, so a 383 would be a nice step up.

Did you say this was a 22ft Bluebird? GVW is 22,000 pounds? Seems like a lot of weight for such a short bus.

I've driven 48 passenger school buses with the 292 six and they pulled pretty decent. We have a 6% grade a little of a mile long east of town, it would slow some but still did okay.

A 350 should do fine in that bus. How did the old 350 do before it blew up?

A 366 or 427 tall deck could be a good replacement. After all thats what they were built for, 4 bolt mains, steel crank lots of tork, will bolt right in and you might find one at a good price..

And LOTS of school busses used them well into the '80s.

Is a 350 enough is a very subjective question. We really need some objective performance measures here to be able to address this question.

I don't think I'd be satisfied, but clearly some of you would be. What would success look like?

IsolationRide do you really care if it's enough for me or one of the others? What would be enough for you?