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B230F vs. FT block differences

blacknite3

blacknite3

Member
Joined
May 17, 2003
Location
Asheville, NC
Can someone point me to a resource to know the differences in the B230 blocks between turbo and non turbo cars. I've tried looking but couldn't find much. Also, I know that the '93+ blocks have the piston oil squirters, but weren't there a few years where they changed something about the main bearings that made them weaker?

The motor in my '91 740 is knocking pretty bad so I'm starting the quest for a replacement. I've found a few options, but am wondering if I need to narrow my search.

Thanks for the help
Patrick
 
The internal difference is in the pistons. The B230FT has a deeper dish in the piston, giving a lower compression ratio (8.7:1 for the turbo, 9.8:1 for the non).

Externally, the Turbo block will have the oil feed and oil drain holes drilled and there may be an oil cooler sandwich plate installed on the block. Otherwise, they'll look the same.

The bearing change was around 88/89 and the change from 9mm to 13mm rods was around 89/90. Look for a '90 model year or newer, with the latest/lowest mileage being preferred, especially if you're just dropping it in as-is.
 
blacknite3 said:
Can someone point me to a resource to know the differences in the B230 blocks between turbo and non turbo cars. I've tried looking but couldn't find much. Also, I know that the '93+ blocks have the piston oil squirters, but weren't there a few years where they changed something about the main bearings that made them weaker?

weaker, but not weak :)


The motor in my '91 740 is knocking pretty bad so I'm starting the quest for a replacement. I've found a few options, but am wondering if I need to narrow my search.

Thanks for the help
Patrick
Click to expand...

and to add to the above post, the rods can be swapped if find one with the thinner rods..
 
Careful what you tell me, i'm not wearing a condom..

i wouldn't have to swap fuel pumps or anything?
 
i would be afraid of the computer differences, there were some 3.1's thrown into the mix in the early 90's na's i think, see what you got is what i'd say. i think the 2.4 to 2.4 is more straight forward

but i know nothing, gl
 
How crazy would it be to use NA pistons in my b230ft to raise compression? any real power gains? Does this make the engine an interference engine with a IPD turbo cam?
 
d34thd34l3r said:
How crazy would it be to use NA pistons in my b230ft to raise compression? any real power gains? Does this make the engine an interference engine with a IPD turbo cam?
Click to expand...

If it isn't already with the ipd t cam then it wouldn't be with na pistons. The outer ring is just the same. But it would likely be easier to find a nice low mileage na engine and swap that in the swap na pistons to your turbo block. It would of had an easier life in terms of bore wear
 
d34thd34l3r said:
How crazy would it be to use NA pistons in my b230ft to raise compression? any real power gains? Does this make the engine an interference engine with a IPD turbo cam?
Click to expand...


Every +T on the board is using NA pistons. you loose some detonation resistance but you get a higher comp motor. I really liked my +T motor and never had any issues from running NA pistons. It felt great on and off boost
 
Im willing to do a swap to NA pistons. Would I still be able to run the same boost? 10-20PSI? I can handle pulling the engine and tearing it apart but I just dont have enough experience with bricks To know how far i can push it. My current mods are in my sig Anyone ever ran this much boost on a +t or a ft with NA pistons?

Is there a chance i'd damage my cam? I can get a whole block for 185 with accesories so i dont really have a problem with blowing up the motor.
 
I shouldn't be able to damage the cam if you melt/grenade a piston.

10-20 psi should be ok, its important to be able to modify timing with the different compression ratio. you won't need or want as much timing if you have more compression ratio.

If you don't have problems with blowing up your motor then let er rip and see what happens.
 
Modify timing? I have mike's chips installed would those controll the timing enough?

And no I dont have a problem with blowing it up =)
Thats gonna bbe my next project.

Would the pistons from a b234 be a direct fit and the same compression as the b230f?
Ive seen a couple of 16valvers in the junkyards so im down to pull one.
 
If you want to raise the compression ratio of your B230FT, the better option would be to replace the headgasket with a thinner one.
 
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