Slapping A Turbo On A 225 odd Fire?

I don't know why I think of this stuff, like I have nothing else to do but keep working on the Jeep.

Has anyone ever done/herd of a turbo installed on a 225 odd fire? I know that there are tons of 231 (Regals) out there with turbos, but I have a 225. I know I would like to have more power in the high RPM range. Sounds like a good way to add some ponys to my EFI'ed odd fire 225.

 

Honestly, I think it would be cheaper just to start with a turbo setup. While it's possible (anything is possible with enough time and money) you're looking at a bunch of custom stuff.

Most turbo setups use a lower compression bottom end. While I'm not, positive those parts probably aren't something you can find easily. If they do exist (big if) you'll probably find them at TA performance, give them a call.

 

That's a 231, not a 225. You can find a bunch of turbo 231's that came that way from the factory.

 

The buick v6 turbo has an 8:1 compression ratio and the 225 has 9:1. If you were to run a turbo on the oddfire you would really need to keep the amount of boost significantly low like 1-2 psi. You would probably need to run high octane fuel too. The biggest problem with boost is having to control pre-ignition. As the 225 was not really designed for a turbo, your motor may not last too long. Again I agree it may be cheaper to just swap in a Turbo 231.

 

an old diesel turbo trick is run 2 head gaskets to lower compression. don't know how well they hold up though.

if you want more upper power, swapout the stock camshaft and get a car flywheel instead of the stock jeep one.

 

That would probably help with the exhaust and intake routing, but without something to lower the compression the amount of boost he'd actually get out of it would be really limited.

You'd probably get more power out of a more agressive cam.

 

You also may want to see what Buick did internally to keep their turboed engines cool. I know that giving a turboed engine piston squirters is a fairly common thing that the munufacturers do to keep the pistons cool using the engine oil. This may mean a larger capacity oil pump and larger bores for the oil passages in the block. They may even cast more or different oil passages into the block for this purpose. keep in mind that to get the more power you usually create more heat. Getting rid of this extra heat is going to be one of your challenges to this mod. One often needs bigger radiators, and sometimes even an oil cooler or two. It has been done before, and you are going down the right road trying to find someone that has done this before. This way you can avoid their mistakes and have a few of your own mistakes to share with the next fellow, or gal as the case may be. Please let us know what you find and how it goes. Thanks, Matt W.

 

It is mechanically easy swap. I used a 3.8 (231) turbo'ed engine from a 84/85 regal. No real mods to the firewall or fenders required. The problem you will run into is as stated above. The 225 runs relatively high compression so you will quickly develop lots of boost (ie. boom). The intake from a 84/85 turbo regal maybe adaptable to the 225 - GM tends to be conservative that way. I will bet that all the bracketry and the turbo will mount right up. Your best bet would be to transplant the computer and engine control system from 84/85 turbo regal. These parts are usually readily available on the turbo buick forums. These 84/85 cars were "hot air" ie no intercooler. The later intercooled setup is faster than the hot airs but we usually don't worry about 1/4 mile times here. I know the computer swap adds complexity to the project but the service manuals for the regal are available (I have a set) and the knock gauge and timing retard/advance (+/- 20 degrees) afforded by computer control might just keep you from grenading your 225. Overall it was a fun project. It really adds a kick to the Jeep. I have yet to trash my stock Trany and tcase. E Mail me if you want further details

 

Just a comment - adding boost puts a lot of stress on an engine. I suppose it depends on what you want out of the Jeep, but I'd think adding cubic inches would be a much easier, cheaper and more reliable way to get more power. Turbos add a lot of extra complexity and moving parts, as well as way increasing the forces on the block, rods and crank.

Any of the small block Buick engines of the Buick line (300, 340, 350; not the Chevy 350 rebranded as Buick) will bolt in to the Jeep engine compartment in place of a 225. You'd have to cut back the grille or use a later grille, but it's a very easy transplant. The T-14 is not strong enough for a V8 IMO though ... unless your driving habits don't change. Likely not strong enough for a boosted 225/231 either.

 

I agree that small block transplant is tried and true. It depends on what you want. I like to tinker. These off the beaten path projects require ingenuity and patience. Conversely, I have done nothing to my 67 that could not be unbolted and put back to stock if so desired. An easier project would be a belt driven supercharger but that is not what he asked about in the original thread. If I remember correctly, one board member toyed with the idea of a home brew electric motor driven forced aspiration set up at one time. I believe all of us like the challenges these older Jeeps entail. Otherwise, we would all just go out and buy new Rubicons.

 

Check with Holbrook Specialtys in Oregon one of the brothers has run a turbo for years. If you can't locate them do a search for the Jolly Jeepers club and contact him there.

 

Interesting thoughts. Thanks for the input.

I could just bolt up a v8 but that is boring. I put fuel injection on the 225 a few years ago because it was different. I thought a turbo would be different.

But I don't think I will go the turbo route. Not at this time anyway. I might just save it for an other time. I already have a cam in it. I am getting ready to bolt up some p&p 231 heads. I will then make my own inside the frame rail headers for them.

That will keep me busy enough for now.

I am glad that some of you have the same opinion as me that a turbo would be fun and different.

It is fun to mix this board up at times with new ideas.

Thanks Again,
Scott

 

hot air intake would definitely bolt up to 231 heads. You could easily use 231 hot air headers. This project has taught me lots about computer controlled engines.

 

Hot air being 84/85 231 turboed Regals.

 

Any more detail about what 231 heads fit on a 225 and what needs modified to make them bolrnon successfully?