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b21ft rebuilding

thats always what i think about i always hear about the b230, is it worth rebuilding a b21ft, biggest weaknesses? or limitations? or qualities, advantages? I think its convenient since it came with the car 🤣🙄
 
JTF said:
thats always what i think about i always hear about the b230, is it worth rebuilding a b21ft, biggest weaknesses? or limitations? or qualities, advantages? I think its convenient since it came with the car 🤣🙄
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I’m no engine builder, just to start.

I’ve always thought of the B2x engines as being overbuilt, which is comforting. I think a common opinion is that it’s unnecessary, which is I guess is exactly what Volvo said in 85.

I think the question anyone would ask is “what do you want?” You can stuff a lot of boost in a low compression engine, but maybe you want something lower boost and well rounded. I think the B21 is OG and cool, someone more practically minded might think that’s dumb.

I have no advice, only conversation starters.
 
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If the car is in excellent shape, you might want to keep it original K-Jet and B21FT for resale value to a collector. Otherwise, LH2.4 and a good B230 block gets you modern EFI, and an engine that you can rebuild at your leisure.
 
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exactly exactly, i do want to do the car justice and keep it classic and as close to original, but then again, the technology is there 😅, and i do think about type A s a lot too, old dream. Ill get pictures accessible soon, its in solid shape seriously..
 
Volvo B2x engines.
B21FT overbuilt low compression. Lots of boost headroom
B23 overbuilt but may need block checked for core shift. Still strong.
B230 initial version of volvos low friction design. Kind of overbuilt but not like the early engines. Has center main thrust bearing and 9mm rods. You get the best fuel economy with these engines.
B230 late 89? Thrust bearing moved back to old location.
B230 1990 or so? improved pistons and larger rods. More strong like the early engines.
B230 1993 Squirters added and probably as overbuilt as the early engines. The latest and best redblock we got from Volvo.

So I stayed with a B21FT because I can add squirters (BMW ones) and I can buy lighter rods and pistons. The smaller displacement is OK because boost. Plus I like the older engines.

However, if you want that more well rounded powerband. Using the higher compression of the B230 turbo engines is helpful. It's why I got 8.5 pistons with my parts hoard.
 
I bought mine from RSI when they were in business. John V can tell you the BMW ones he has used. I believe the part numbers are in the squirter thread on the sticky area.
 
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I’d stay with the b21 for the simple fact they don’t suffer from piston slap. Not that it’s a big deal and the squirters pretty much resolve that potential issue anyway, but I have never ever heard a b21 or b23 with piston slap. It drives me nuts. Also, the b21 will have a forged crank and rods to begin with, I forget if the b230’s have a forged bottom end. Kind of trivial at 350hp anyway but it doesn’t hurt. Plus I do like the look of the old style valve cover under the hood of an older 240
 
The only thing I had a problem with was the early heads have the big cooling ports, I went through a couple or so 160 heads with bad tunes and failed fuel components/ connectors. My last build is a 530 head with small cooling ports from a 93 and an 84 B23 bottom end with nos RSI h beams and factory B23E turbo pistons which I believe were also forged from what I could tell. The timing cover needs addressing, the cam alignment notch is cast on the early head covers and part of the timing belt cover on the newer heads. I cut part of the backing plate on the 530 style and put the old style timing cover on. STS sells a part that also does the same thing. I think there are some early style heads with small cooling ports, maybe 398 or 405 from what I remember but I couldn't find one.
 
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really appreciating the conversation going, this is so helpful 💪
one thing i realised through this, and never admitted even though a detail, i really do enjoy the vintage look of the b21, with the ipd aluminum oil cap, it is a beauty
 
VB242 said:
The only thing I had a problem with was the early heads have the big cooling ports, I went through a couple or so 160 heads with bad tunes and failed fuel components/ connectors. My last build is a 530 head with small cooling ports from a 93 and an 84 B23 bottom end with nos RSI h beams and factory B23E turbo pistons which I believe were also forged from what I could tell. The timing cover needs addressing, the cam alignment notch is cast on the early head covers and part of the timing belt cover on the newer heads. I cut part of the backing plate on the 530 style and put the old style timing cover on. STS sells a part that also does the same thing. I think there are some early style heads with small cooling ports, maybe 398 or 405 from what I remember but I couldn't find one.
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The 405 I have has big coolant ports.
 
FYI the 405 heads that came to the Canadian market of which I have a couple are all BCP. The only SCP 405 heads I know of Volvo only used on the rare Europe and UK only B23ET. I was able to buy one of those heads and sadly it had cracks between all the valve seats.

There may be some SCP kjet heads on the last of the B21FT we got. But I haven't seen any although some say they have. I am using one on my turbo now but I keep the boost around 11-12psi as Mike Aaro wrote to not exceed boost significantly over stock levels without welding the head.
 
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as well ill be keeping an eye out for upgraded intake and exhaust manifold, think ill be going for the b21 in the car right now! First step done 🙌
 
I don't know what your intake manifold budget allows for. But here is an option to check out. A better flowing intake than the stock efi manifold is the stock kjet manifold. You can have efi bungs welded to the runners and make a mounting for the bolts for the efi fuel rail. I bought a kjet manifold modified by Nathaninwa this way from DET17 in his swedish underground parts sale. I've never welded aluminum and it can be challenging so I would have a shop do this mod.

Another option is to use the kjet manifold and put the injectors in the kjet fuel injector holes in the head. I've seen this setup on here. I think Hank Scorpio did this? I prefer the efi injectors firing down the manifold runner so they don't get the heat from the cylinder head. But it's all food for thought.
 
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The way to do the Skandix shipping is to buy a bunch of stuff. Your shipping cost is for a standard amount of weight. So buy a few things as it doesn't change the shipping cost until you exceed the fixed weight amount.
 
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dl242gt said:
I don't know what your intake manifold budget allows for. But here is an option to check out. A better flowing intake than the stock efi manifold is the stock kjet manifold. You can have efi bungs welded to the runners and make a mounting for the bolts for the efi fuel rail. I bought a kjet manifold modified by Nathaninwa this way from DET17 in his swedish underground parts sale. I've never welded aluminum and it can be challenging so I would have a shop do this mod.

Another option is to use the kjet manifold and put the injectors in the kjet fuel injector holes in the head. I've seen this setup on here. I think Hank Scorpio did this? I prefer the efi injectors firing down the manifold runner so they don't get the heat from the cylinder head. But it's all food for thought.
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I ran EFI injectors in the k-jet injector holders when I was using the 160 heads, I had a hard time keeping a good seal. I made some fuel rail holders that bolted to the injector hold down bolts but once I went to the efi head I went to the spaghetti intake manifold, now I'm running KL racing manifold and it's way better that both the k- jet and efi manifolds.
 
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enjoying rereading the thread and figuring out where i'll go and what money will buy basically, i sometimes am hesitant to ask advice cause i know things have been asked hundreds of times and there are threads but i guess every car and situation no matter how similar have unique combos and circumstances so, thatll be a version for me. I have been taking pictures and videos of different steps from buying the car in alberta in october to driving it back to quebec in 4 days, plating tho oh what fun... 🤣🙈. Will figure out a way to share media over here. Thanks for all your inputs, im no mechanic but theres lot of sense in here 🙌. A list is being made!
 
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