B21f intake manifold swap - What’s involved

[Vol242vo]

Looking to clean up my engine, I like to look of the B23/230 manifolds. Anyone have a link, there has to be one just not having luck searching. Or let me know what’s involved in the swap, thank you in advance.

[VB242]

If you're still running kjet you would have to block off the ports for the electronic injectors. Also there isn't a provision as far as I know for the cold start injector but that I'm not 100% on. I went out of my way to keep the k-jet manifold when I plus tee d my car for the extra torque, you are likely to lose performance by switching.

[Vol242vo]

Ok good to know. Maybe I’ll stick with it and go another route. Thanks for the tip.

[DET17]

I'm about 90% of the way converted on my 940..... using the B21F "EFI" intake. All the details you should need are in my build thread (or will be in the last installments). There are several options on where to add the IAC port to LH vehicles..... just depends on the vacuum port requirements of your particular application. While there is not YET a definitive thread/article on the process, a detailed search in this area of TB will yield most of the details to answer your questions.

[soclosenotnear]

^^ sounds likes he was wanting to swap the other direction

[DET17]

Originally Posted by soclosenotnear

^^ sounds likes he was wanting to swap the other direction

Well, that wasn't clear to me. Why anyone would WANT the B230FT intake with it's known deficiencies, is beyond me. To each his own!

[PCH]

Originally Posted by DET17

B230FT intake with it's known deficiencies,

Any credible info on that? I would imagine the later manifold had better science behind it.

[Wren]

Originally Posted by PCH

Any credible info on that? I would imagine the later manifold had better science behind it.

Nope. The best flowing stock manifold is the B21F. It's just that the B21FT one is so bad that anything is an improvement, even the B230FT one.

[PCH]

Originally Posted by Wren

The best flowing stock manifold is the B21F.

I looked in the older threads and couldn't find any flow bench results or dyno numbers new vs. old. Just statements on how people feel about the plenum volume and throttle body positioning. Why did Volvo decide after about 6-7 years of using the K-Jet style manifold to completely redesign it (not only add injector bosses) and make it worse?
The emission improvements were always a factor so may be the new manifold was better for even Cold Start Injector, PCV and EVAP flow distribution? But that doesn't mean it had to become more restrictive. And then they stuck to the same manifold from about '82 (LH2.0 cars) to late 90's without needing change?

[Wren]

Originally Posted by PCH

Why did Volvo decide after about 6-7 years of using the K-Jet style manifold to completely redesign it (not only add injector bosses) and make it worse?
.

For that matter, why did Volvo decide to get rid of the B21F manifold and go with the craptastic B21FT manifold? Only the shadow knows.....

[dl242gt]

The B21FT manifold is a spitting image to one of the carburator intake manifolds. It isn't the best intake as these go. There used to be pictures of a 242 turbo rally car on Swedespeed that was making 300hp. It was still kjet but Volvo changed the intake manifold to the efi one without the injector bosses machined in it. The whole kjet system is changed from anything we got stock. lol. 300hp would be nice. Also has a 90+ exhaust manifold as I recall.
Here it is. http://www.swedespeed.com/news/volvo...rbo-rally-car/

[Redwood Chair]

Originally Posted by Wren

For that matter, why did Volvo decide to get rid of the B21F manifold and go with the craptastic B21FT manifold? Only the shadow knows.....

2.5" CIA tubes and nice long runners on the D-jet manifold too, but that went the way of the Dodo bird as well.

[RolinOldies]

Originally Posted by PCH

I looked in the older threads and couldn't find any flow bench results or dyno numbers new vs. old.

No doubt the 'F' manifold is the better, and sure the '21FT' is bad flow, so the B230 style must be somewhere in between but where exactly only a flow bench can tell. My guess it is much closer to the 'F' than to the '21FT' and i don't think it matters that much below 350HP, or am i just kidding myself

[turbotankshane]

Originally Posted by RolinOldies

No doubt the 'F' manifold is the better, and sure the '21FT' is bad flow, so the B230 style must be somewhere in between but where exactly only a flow bench can tell. My guess it is much closer to the 'F' than to the '21FT' and i don't think it matters that much below 350HP, or am i just kidding myself

I'm inclined to agree with you. I don't think its a limiting factor in the majority of goings on around here.

[blkaplan]

You dont need as good of an intake manifold when you add .2 liters of displacement... or a turbo or EFI.

[DET17]

Originally Posted by PCH

Any credible info on that? I would imagine the later manifold had better science behind it.

Scant little. I mined data from TB going back to '05, before I made the leap to adapt the B21F to my 940 (nearly complete, but yet in process).

In all those threads, lots of "butt dyno" and "empirically determined" info. Earlier than that, I believe someone had some EGT data which indicated a lean cylinder.... which was guessed to be caused by an intake constriction. I did find a thread with flowbench data, but there was no "head to head shootout" comparing the B230FT to the others.

I made my decision based upon PM interviews with 3 folks who converted from the B230FT to the B21F; 2 in Europa and 1 in Canada. The only dyno data I've seen for the B21F (E in Canada ?) showed a brilliantly flat torque curve, as opposed to the peaky curves I've seen on several B230FT intake data.

Like you, I would have suspected LATER would be BETTER. The notable differences in design are (1) runner inside diameter and "straightness", and (2) the 2X or 3X increase in the common plenum. Since there is nothing unique about this Swedish 4 banger, intake design theory illuminates the differences those elements make to performance.

Last - my $ is on the B230FT intake for improved emissions and idle quality.... the WHY.

[VB242]

I own cars with both, but the b21f manifold car is modified with MS and a T5 ipd cam etc, the other is a stock 780 with the b230ft and autotragic, the b21f car feels more powerful all around of course but it also feels more torquey. I don't have real data other than it there b21 dynoed 215hp before I figured out I had a fuel delivery issue.

[PCH]

Originally Posted by blkaplan

You dont need as good of an intake manifold when you add .2 liters of displacement... or a turbo or EFI.

Yes, the pounds of boost can overcome any restriction there is.

Originally Posted by DET17

Scant little. I mined data from TB going back to '05, before I made the leap to adapt the B21F to my 940 (nearly complete, but yet in process).

In all those threads, lots of "butt dyno" and "empirically determined" info. Earlier than that, I believe someone had some EGT data which indicated a lean cylinder.... which was guessed to be caused by an intake constriction. I did find a thread with flowbench data, but there was no "head to head shootout" comparing the B230FT to the others.

I made my decision based upon PM interviews with 3 folks who converted from the B230FT to the B21F; 2 in Europa and 1 in Canada. The only dyno data I've seen for the B21F (E in Canada ?) showed a brilliantly flat torque curve, as opposed to the peaky curves I've seen on several B230FT intake data.

Like you, I would have suspected LATER would be BETTER. The notable differences in design are (1) runner inside diameter and "straightness", and (2) the 2X or 3X increase in the common plenum. Since there is nothing unique about this Swedish 4 banger, intake design theory illuminates the differences those elements make to performance.

Last - my $ is on the B230FT intake for improved emissions and idle quality.... the WHY.

I can add some insight on that too then. Tried 4 different manifolds on a N/A K-Jet B21F no Lambda with K-cam and manual trans.
The stock B21F, B21FT, early LH2.0 and the latest B230 manifolds. Settled on the LH2.0 which is basically same as B230 except it was easier to mount the K-jet injectors because they are secured to the runners individually and not held down by the fuel rail like EFI ones are. I think that manifold also doesn't have the bumps on the inside of the runners where the injectors come through.
I feel that the early B21F manifold was sort of killing the top end that the K-cam had available but was nice for take off power and smoother idle (slightly higher that factory setting- you got to with K-cam)
The B21FT was obviously the most restrictive of all and no gain but the throttle body pointing up was easier to connect the ducting to. It was a transition to the latest EFI manifolds that really brought up the top end power.
I had the insides honed smooth on all manifolds except the B21FT with squashed runners.

[photoman327]

I’m also going to the B21F intake on a B21FT. My Red 84 was already hacked with a untuned Megasquirt when I got it and I have a couple of intakes and One modified by Nathan. The long runners got to be a lot better flowing. Also read everyone couple find and all points to worth the trouble and then turn up the boost.

[DET17]

Originally Posted by VB242

I own cars with both, but the b21f manifold car is modified with MS and a T5 ipd cam etc, the other is a stock 780 with the b230ft and autotragic, the b21f car feels more powerful all around of course but it also feels more torquey. I don't have real data other than it there b21 dynoed 215hp before I figured out I had a fuel delivery issue.

I'll go out on a limb here and guess the B21 is boosted? If not, those'd be damn impressive #s for NA!

Are you running injectors in the head or intake of the B21F? Pics of this abomination?

[VB242]

[IMG]2016-02-06_04-25-42 by John Skiba, on Flickr[/IMG]

Older pic, no longer have the Heineken can heat shields, also different injectors. I use the k-jet o-ring on the bottom of the EFI injector.

[VB242]

Yes boosted and Microsquirtd, emusa 20g, 3" side exit

[oldschoolvolvo]

Originally Posted by VB242

[IMG]2016-02-06_04-25-42 by John Skiba, on Flickr[/IMG]

Older pic, no longer have the Heineken can heat shields, also different injectors. I use the k-jet o-ring on the bottom of the EFI injector.

Interesting...so you don't bolt the fuel rail to the manifold, just let the thicker o-ring secure the injector to the k-jet injector holder?

[VB242]

No I made some standoffs that bolt to the k-jet injector holders that hold the fuel rail down with the 2 fuel rail mounts.

[VB242]

2017-01-01_05-28-35 by John Skiba, on Flickr