1st gen/323/GLC Engine and Drivetrain Engine/Drivetrain Modification Discussions for 1990-1994 Models (BG chassis) and 1981-1989 GLC/323 Models (BD and BF chassis)

Sohc to Dohc

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Old May-13th-2003 | 06:37 AM
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Sohc to Dohc

I was just wondering if anyone has or knows anyone that has done this swap. I have the list of things that i need to buy but im not sure exactly hard it will be to do it. My ending plans are ofcourse adding a turbo.

From what ive read the sohc engine can be turboed right now as it is with a custom exaust manifold, what are the differances in the potential in the engines? Im not trying to get an insane hp count, close as 200 as possible atleast.

Would it be, in your minds, smarter to turbo the sohc engine and save money for tunning?

Thanks for any answers you can give me, i am very serious about getting this done before the snow comes back.

Glenn
Old May-13th-2003 | 11:11 AM
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"At least 200hp" is not little at all. If I were you, I'd find a low mileage DOHC engine and swap that in, then go from there. I hope you know that making a custom manifold for you SOHC engine will not be cheap at all. You might as well invest a few hundred more and get a DOHC. You'll have much more potential at the end. Just my opinion.
Old May-13th-2003 | 06:13 PM
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yea i was thinking about the dohc route, but out here in suv/truck land its hard to find a protege period. I dont want to go with a bpt because of the things i read in a thread on this board.
Old May-13th-2003 | 08:20 PM
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Then just drop the upper part of a bp on your bottom end it has been done and it's a little faster then a bp has the compression ratio hisn't the same has a bp engine
Old May-13th-2003 | 09:04 PM
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just to clarify, the SOHC and DOHC are both BP engines.

IMHO, i'd do the complete BPT motor swap. But a SOHC turbo project would be fun.
Old May-13th-2003 | 10:33 PM
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What have you read about the BPT? The arguments that the BPT is a little more flow restrictive than the BP? IMO, if you decide on a swap and you want to have a turbo motor, you might as well do a BPT swap and get everything over with at once. This, however, will be a bit more pricey.
Old May-13th-2003 | 11:47 PM
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Originally posted by kagekun
yea i was thinking about the dohc route, but out here in suv/truck land its hard to find a protege period. I dont want to go with a bpt because of the things i read in a thread on this board.
If your planning on going DOHC just to go to Turbo, just go straight to the BPT, you can always just port the head later if you want to go for bigger power. The BPT will get you to where you already said you want to be.
Old May-14th-2003 | 12:22 AM
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Red face bp turbocharged

This should be your solution,bp with turbo manifold off the bpt ,10psi,kick azz car. ive got that set up in an 88 323.
Old May-14th-2003 | 08:30 AM
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the bpt manifold bolts right on the the sohc engine? i would think these is a suttle differance.
Old May-14th-2003 | 11:33 AM
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I think the bottem end is the same, so everything can bolt up.
Old May-14th-2003 | 11:44 AM
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I live a little far away from ya, but I got a DOHC BP engine I am looking to sell, if ya want it.....
Old May-14th-2003 | 08:58 PM
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the BPT manifold will not bolt up to the SOHC head.
Old May-15th-2003 | 01:51 AM
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alright, well i found a dohc engine close to where i am, figure ill just do that swap and then turbo it. Any suggestions on the turbo, the shop up here (almost dominated by honda) uses 15g's witch i was told is 5-8psi, is that enough to make a big differance?
Old May-15th-2003 | 11:18 PM
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5-8psi will net you about 190hp, about the same as a GTX, as the GTX has a stock boost of 5-8psi, but the boosted BP will show a bit bigger gain with the same psi than the BPT.
Old May-15th-2003 | 11:20 PM
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Originally posted by PseudoRealityX


Manifolds don't bolt upto the "bottom end", they bolt to the head, which is different.
i think he meant the head bolting to the block. I personally have never got confirmation that the valve>piston clearence isn't an issue.



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