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Early B21 + T?

Slobodan

New member
Joined
Mar 29, 2004
Location
Northwest part of Oregon
I've got this Early B21F with 8.5:1 CR (slighty dished Pistons)
First question. Are these pistons going to handle K-Jet Turbo boosT of 12psi to 15psi?
Second question. Would I be better off swapping out those pistons for the B21 flat tops (9.5:1 CR pistons)

And thirdly, I want a high comp B21 on the cheap for +T. Should I just rering the 8.5:1 pistons and get the head shaved down extremely far in order to raise compression. And how far could I shave the head to achieve that sweet spot of 9.5:1? I have MLS stock thickness head gasket begging to be used. Got it cheap.

Going to be using either V cam or IPD Turbo. Going to try this proposed engine with K-jet and stick to around 12 psi. If K-jet can't cope with the high CR of this setup. then I will just go back to LH 2.2 which I know will be able to handle this higher CR. I had at one time, a 9.5:1 CR B21F +Teed with LH 2.2 Turbo WAY back, It was awesome!! Ran 15psi, moved pretty good and was good on gas!! 28mpg hiway. Currently I've got B21FT K-Jet and uhh not great milage. motor seems tired to me. eats oil, and generally feel weak after I raped it under LH 2.2 E85 with improper tune and 20psi.
 
B21 / B23 rides the wave of the good hearty B20's legendary reign.
b230's are redesigned to be low friction and thus not as robust. Especially the early ones. sure the 90+ B230's are a bit better, but not no B21/B23. Excuse me. Squirters or not.
 
8.5:1 is is high as anybody with any sense should go with a motor you want to give some fun boost to.
Leave crap alone and just add turbo and figure out whatcher gonna do for boost enrichment..

And just note---the low friction concept has nothing to do with the crappy totally inadequate rods.. Too tired to splain more butno connection between that and B230s inadequacies.

I mean if you want to give it 4 PSI, like the sorority sisters here or get all serious and up it to 8 psi, fine up the comp, but what's the point of that?
 
yeah well, I know there is more wrong with B230's...

I won't go into those details either.

I really miss that B21F I turbo'd long ago.

LH 2.2 EZK setup from 740 Turbo '85 ~ '89.

I was rocking 15psi safely. with 15deg base idle timing.

friggin thing was solid. almost 30mpg hiway. I am not fibbing. that motor was the stock motor from my 242 GT. Something I did stupid was get a girlfriend (A distraction) was in the middle of swapping intakes to the B21F intake was using the B23F intake, Left the engine with out the intake on it no rags Nothing covering the intake ports. Left it like that for the whole winter in the woods. in the spring time I finished what I was doing and it ran fine for a couple months then It was a smoking b*tch and ran all weird, low on power without boost, did a comp test 120 180 120 180 DAmn Rust formed over the winter while those two intake valves were open slightly. Enemy condensation occurred and ruined everything good about that setup.

My goal is to use this free bottom end refresh it, and comp test before installing it hoping for the same numbers or better. (better than 180psi) This I feel should do it. with a cut head.
 
yeah well, I know there is more wrong with B230's...

I won't go into those details either.

I really miss that B21F I turbo'd long ago.

LH 2.2 EZK setup from 740 Turbo '85 ~ '89.

I was rocking 15psi safely. with 15deg base idle timing.

friggin thing was solid. almost 30mpg hiway. I am not fibbing. that motor was the stock motor from my 242 GT. Something I did stupid was get a girlfriend (A distraction) was in the middle of swapping intakes to the B21F intake was using the B23F intake, Left the engine with out the intake on it no rags Nothing covering the intake ports. Left it like that for the whole winter in the woods. in the spring time I finished what I was doing and it ran fine for a couple months then It was a smoking b*tch and ran all weird, low on power without boost, did a comp test 120 180 120 180 DAmn Rust formed over the winter while those two intake valves were open slightly. Enemy condensation occurred and ruined everything good about that setup.

My goal is to use this free bottom end refresh it, and comp test before installing it hoping for the same numbers or better. (better than 180psi) This I feel should do it. with a cut head.

Ring side clearance..max .004. More and the piston is scrap.
Kiss the head "to clean"
 
It's all in the tuning.
Local guy is almost done with his B21F+T, and fige runs a 10.3 CR B23F with an evo8 turbo at 19psi.

Both cars make me annoyed of my low comp B21FT.
 
B21F seems ideal for boost. Not-too-high static compression ratio, smaller bore, pistons are plenty strong (same material as B21FT pistons), obviously the strong bottom end. Do it.
 
kjet should be able to keep up if you're good at getting it fuel. the kjet dizzy is gonna suck some power but it'll be safe at least

get a wideband, add boost, lift when lean, report results. in the end, a motor is a motor. and it's a b21, it was overbuilt
 
b21's are strong as ****. mine wouldn't blow up an I ping'd the crap out of it on a daily basis. for a while I didn't even hav emy wastegate hooked up just running hella boost. I see no issue with boosting a b21 they are like the tank of Volvo motors in my opinion
 
I had a thought run through my head a couple of times.
It goes something like this.
and it might be hideous.

K-jet fuel system + EZK and LH 2.2 Being ran both together!

Ofcourse I'll have a couple switches and solenoids to Divert fuel to the system I am running or not. Like on the fly flip some switches and be running only LH/EZK and then if I wanted go back to K-Jet with EZK just, but I'd need LH running computer wise so that EZK knows the load of the engine from the AIR Mass meter. but it won't be pulsing the injectors.
I'm talking some crazy talk right here. And possibly even running both fuel systems at once! and get that turbo boosting 25psi. hahaha fing NUTSSS.
 
I had a thought run through my head a couple of times.
It goes something like this.
and it might be hideous.

K-jet fuel system + EZK and LH 2.2 Being ran both together!

Ofcourse I'll have a couple switches and solenoids to Divert fuel to the system I am running or not. Like on the fly flip some switches and be running only LH/EZK and then if I wanted go back to K-Jet with EZK just, but I'd need LH running computer wise so that EZK knows the load of the engine from the AIR Mass meter. but it won't be pulsing the injectors.
I'm talking some crazy talk right here. And possibly even running both fuel systems at once! and get that turbo boosting 25psi. hahaha fing NUTSSS.

That would never work. An automotive engineer would have a harder time getting that to work than a jiffy lube grease monkey would installing MS.
 
I had a thought run through my head a couple of times.
It goes something like this.
and it might be hideous.

K-jet fuel system + EZK and LH 2.2 Being ran both together!

Ofcourse I'll have a couple switches and solenoids to Divert fuel to the system I am running or not. Like on the fly flip some switches and be running only LH/EZK and then if I wanted go back to K-Jet with EZK just, but I'd need LH running computer wise so that EZK knows the load of the engine from the AIR Mass meter. but it won't be pulsing the injectors.
I'm talking some crazy talk right here. And possibly even running both fuel systems at once! and get that turbo boosting 25psi. hahaha fing NUTSSS.

You gotta quit smoking that indoor weed, they use bad chemicals to raise it.
 
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