Inliners International Forums General Discussion Hi Performance 206 Chev engine swap

Good afternoon all,

I would like to replace the 206.8 C.I. engine in my car with a full pressure 235, 261 or jimmy 270 engine, but do not wish to modify the firewall and cannot move the radiator. I also would like to retain the original transmission and torque tube driveline. Reliability and hill climbing power are the objectives. Are the above named engines, with short water pumps, close enough to the length of the 206? If the answer is unknown, could someone post the length of their engine from back of head to front of water pump, please?

TIA

My 261 is roughly 33" and my GMC 302 (same as 270) about an inch longer. This is from the back of the head to where the fan bolts on to the water pump shaft; both are standard water pumps. The GMC is bulkier in the timing cover area and the actual block is almost 2" longer than a 235. I don't know whether your existing bellhousing will work with these engines though - what car is this for?

Thank you for the feedback Jack,

The car is a 1933 Master four door sedan. The car seems more sluggish than the 32 two door I had in the late fifties. That car was stock except for a shaved head and a homemade split manifold made from a 1931 exhaust manifold, but was never beaten by a flathead Ford in stoplight gran prixs.

hi, I am in the middle of replacing a 206 in a 31 coupe with a 235. the 235 is actually shorter than the 206, but will not bolt to the 206 bellhousing, so you will need a 235 or 216 bell, the 216 bell or 235 bell has the mounting holes on the front for the orig 216 center mounts and will mount up. the oil pan will not clear the trans mount/ crossmember, I have not figured this out yet, possibly notching the pan or moving the crossmember. my orig thought was to use the torque tube, but the chev trans is weak. I build early rods and will not use late model parts so there is not many options. early packard is one and can be adapted to the torque tube. hope this helps

One other consideration is to run without a fan, but mount an electric pusher fan in front of the radiator. If the cooling system is in good shape, this should be adequate for all but the most severe heat climates.

Thank you 32 cyclone,

Would an early 1938 Buick transmission have the same diameter torque tube as the Chevy? A friend of mine used the Buick behind a built sbc with good results in 1957. The Chevy transmission is geared as though it were meant to be a four speed, but somebody left out third gear.

Jack,

I believe the radiator is too close to the grille on 33 to allow the placement of a pusher fan.

Thank you for the responses.

bald eagle. forget the elec fan, look stupid and just another thing to go wrong, like I said the 235 is definately shorter, if you use the late 235, look on ebay or I will send you the link . theres a guy that has a adapter for yse on a late engine that will yse the early 235 pump and even shortens the motor more, as for the treans, I used a buick trans on a sb chev a few years ago, I'm not sure on the torque tube but the trabs will go onto the truck bell, the trans is very strong, you will never break it, the problem is that alot of guys just go with the new stuff, it's easier, I am a diehard, I am not interesred in the end result ynless it looks like it came from 1955, hope this helps. by the way the jimmy is longer and if you want the cubes use a 261 chev, same dimensions as a 235

Thank you 32 cyclone,

Are the 55-62 235s enough better than the 53 powerglide or the 54 235s to make much difference? The early full pressure engines have more the look of the 206.

Hey Bald Eagle . . .

'Better' is subjective and depends on what you want from the power plant. If you are after a stock look to run under normal street conditions then a '53 or '54 is a definite option if you can find one. Heck swapping out a 206 for a '40s High Torque dipper engine would be a significant step up for that matter.

That said, the later 235's are somewhat more plentiful and offer more horse power at stock specs (135-140 versus 108-115 for the early full pressure engines). And if you're looking to hop-up and really rev then the later design is a more economical starting point.

It comes down to what you want to invest your rebuild dollars into . . .

regards,
stock49

Pre68 Dave has given lots of good advice on this exact swap. He is over at stovebolt.com from time to time - you might do a search on 206 and swap over there as I am sure he has written up the combo of parts that makes this swap an easy one on more than one occation - might even be in the tech tips.

Will do, thank you Ken.

Bald Eagle,
this change is not that difficult if you are truly intent on doing it and are going to be content with the other limitations of the car. I performed a very similar swap on my 35 master back in the early 70s when I changed the 206.
Firstly I suggest that you read the tech notes on this site describing how to swap out a 216 for a 235 blue flame, and this contains a great deal of the information you will need.
The key difference is that your 33 master bell housing is different, ie the bolt pattern is larger. On the 34-36 master, this is the same as a 34 - 47 Pick up. In my case I fitted a bellhousing & matching clutch ec from a 42 216 Pickup & this matched the original 35 gearbox, enabling original rear mount to stay and a minor bracket change for the rubber bellhousing mounts.
At the front, it is going to depend on the age of your blue flame. If it is an early one with front mounts, it will be easy. If not, you will need to get a 216 front plate and swap it as per the tech notes referred to. It is simply a matter of then making some suitable brackets to attach to the front crossmember to move the engine mounts rearward a little.
Once done, you will find the remaining changes minor.
Good luck, Kiwi Chevy
.

Thank you for the tips Kiwi

AS the 270 is about 1 1/2 inches longer than the 235, it seems that the 270 could be installed in place of the 206 without modifying the front mount, right?