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Crown bus engine upgrade? Bovis 9-5-06  
Is it possible to swap the cummins 220 mounted to a roadrunner 10 speed tranny for a smaller, more modern cummins like a 6bt or a 600 that provides more horsepower and electronic controls? I'm looking for cleaner burning and better milage. I'm also thinking about more horses in a smaller package with the newer engines. Am I right? Thanks.
Re: crown bus engine upgrade? Phil Feinstein 9-6-06  
If you take a look at, you'll see the replacement of a 4-71 Detroit Deisel with a 391 Ford V8.

There's no doubt in my mind that it can be done and that you'll get more power and efficiancy with a newer style of deisel motor. There are a few considerations.

* What is the absolute size of the engine bay?
* What is the length/width/height of the engine that you want to swap in?
* Does the transmission attach in a manner you can live with?

Obviously, if the motor is bigger than the engine bay you can't use it. As a rule of thumb, you shouldn't use an engine that exceeds 90% of any dimension in the engine bay just for ease of service. If you look at the 4-71 to 391 conversion, you'll see that he had to craft motor mounts and lucked out because he had a heavy duty trans that could be grafted to the transaxle via a driveshaft. The roadrunner was a pretty common tranny at one time, so you may find that it will bolt up to a newre engine or that a bellhousing is available to connect to the newer engine.

DO YOUR RESEARCH. Nothing kills a project like depending on a part that doesn't exist.

Hope that helps!
Re: crown bus engine upgrade? Mark Wolfe 11-9-06  
I own a '68 model with the 220 and a 4:55 tranny. I'm told through Ft. Worth Gear and Axle that changing the ratio to 3:70 or there abouts could give 65 mph @ 1500 rpm and better mileage. I am wondering if the horsepower on this 220 could sustain the bigger rear end and if this is even possible. Thanks.
Re: crown bus engine upgrade? Jackie 11-29-06  
I'm not sure what you are attempting to do as you already have the best setup for your Crown. If your just looking for more horsepower, shop big rig wrecking yards for the turbo for your engine. That will change your horsepower to 262. You'll probably have to install lower compression ration pistons as well, or limit your boost pressure to a lower setting. Check with your local Cummins dealer about such a project (asking is free). If your seeking more efficiency, then there are several ways to go. One is to consult your Cummins dealer about the best differential ratio for your needs and/or get your injection system updated including computer control. which may also be available through wrecking yards. These changes will be a lot easier and way less costly than an engine swapout.
Re: crown bus engine upgrade? Aaron 2-17-07  
Adding a turbo, haveing the timeing changed, and a calabratiopn of the fuel pump is all you'll need to do to upgrade the 220 to a 262, also install a proymeter at the dash to watch for excessive engine heat 1200 to 1300 is all you want to push a 262, also adding a set of Jacobs brakes will help on the down hill grades. Parts are still available for this motor but getting spendy.
Changeing to something else might be a problem as the Crowns laid the motor on its side for the busses, they we called the pancake 220's, they are getting hard to come by, 335's were also pancaked but none to had that I have seen.
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