R-Sport B21AT turbo build

jamesinc · 2020-08-09T12:44:17+00:00

The B21 engine was, after all, the power behind the 1986 ATCC winner. What are your plans for it - NA, old school K-Jet turbo, Volvo Turbo Cup carb turbo, or...

whitedragon64

Hi James -new guy here, Mate you have these welsh plugs in backwards The concave face faces outwards

Nice build so far by the way top job ?️

ramrod

No he doesn't

This is a B21

Not B230

whitedragon64

Yes of coarse my bad disc type not the cup type

jamesinc

@whitedragon64 yeah as ramrod says these are the dome-type, so they started convex and they've been caved in a bit with a socket and a mallet to seat them.

PS welcome to the forums!

whitedragon64

Cheers James

jamesinc

I am currently muddling my way through head gasket selection. The 405 head's chamber overlaps the B21 head gasket ever-so-slightly on the exhaust valve side. It's the right size for the bore so will have to compare the chamber on the 405 to the B21A stock 160 chamber. I might just fit the head and look in from underneath to see how it lines up, although that would be a pain because the bottom end is already assembled.

Worst-case scenario I will scrap the 405 head and use a 160 head, although hopefully I can avoid that as it will require redoing the head from scratch.

Philia_Bear

If using a b23 spec head on the b21 spec block you must use the b23 spec gasket

You just end up with extra quench pads all the way around and a slightly lower cr

jamesinc

Philia_Bear
If using a b23 spec head on the b21 spec block you must use the b23 spec gasket
You just end up with extra quench pads all the way around and a slightly lower cr

Yeah my machinist was of similar opinion, we test-fit a B230 gasket and a B21 gasket and the B230 one was the better fit. He said ideally we'd use a gasket size about halfway between the two but I think I'll just run a B23 gasket

VolvoHordz

Yeah I'd just run a b23 gasket.

Major Ledfoot

Which head did the Volvo Turbo Cup cars use? 398 or 405?

jamesinc

Major Ledfoot
Which head did the Volvo Turbo Cup cars use? 398 or 405?

They ran 405 or 531 heads according to @Anthony, with all modified by the legendary Grottis in Sweden

Spac

Not worth getting a custom gasket made?

There is/was a bloke in Canberra making MLS gaskets at a good price. I can’t tell you the business name, I only knew him as Uncle Clive - but I am still FB friends with his nephew (hence why I know him as Uncle Clive).

dmc

I have used HG gaskets in Warrandyte Vic and he is very good. You may also get a refrigerator magnet!

I think the one I had made was about $200 using a template he already had. It was a 4 cylinder gasket.

jamesinc

@dmc do you have any pics of the gasket? I might call him next week and see if he can do one up with a custom bore size for me, but otherwise I'll just run the B23 head gasket

dmc

It was for a Ford 100E engine. Fairly sure it will not fit a B23 :-)

If you sent him a b230 gasket and measurements of the bore he should be able to make a custom one.

jamesinc

I am changing plans for the turbo due to the turbine flange sizes and my desire to retain the original exhaust manifold. So, I will stick with the original Garrett TB03. However, the one I have is truly clapped out and the turbine housing is cracked in a few places. Basically, all I'm retaining from the original turbo is the compressor housing. The CHRA will be new (I've switched to an equivalent part, the Garrett TB0350) and the exhaust housing will be new also. I'm going to use an ATP 5-bolt wastegate/housing to 3" V-band for this. All the fasteners and so on will all be new too.

jamesinc

The cylinder head is finally done, and I've just lapped and installed the valves tonight.

Now I need to select a camshaft! I have a few on the shelf, and my choices are the OE-spec A cam, or D, H, K, M, or VX. Or I could get a new cam entirely.

The K-cam has gone well with my B21E and M46 but I wonder with the turbo if it will still be suitable? What are your thoughts, Oz Volvo universe?

Philia_Bear

jamesinc
The cylinder head is finally done, and I've just lapped and installed the valves tonight.
https://cdn.ozvolvo.org/uploads/940/9CB1QZFZ6BJ5.png
https://cdn.ozvolvo.org/uploads/167/8K0W9D2JDSI4.png
https://cdn.ozvolvo.org/uploads/057/W4MTYWX488D9.png
https://cdn.ozvolvo.org/uploads/506/AGV2R7I98MTS.png
Now I need to select a camshaft! I have a few on the shelf, and my choices are the OE-spec A cam, or D, H, K, M, or VX. Or I could get a new cam entirely.
The K-cam has gone well with my B21E and M46 but I wonder with the turbo if it will still be suitable? What are your thoughts, Oz Volvo universe?

I Might have an rsi stage 2 sitting on my shelf.... message me

Major Ledfoot

Going by the numbers, a T. Or the M. Why? Less overlap.

No experience, just going by the numbers.

carnut222

Major Ledfoot
Going by the numbers, a T. Or the M. Why? Less overlap.
No experience, just going by the numbers.

Not to hijack the thread, but I've been wondering about cam in my supercharged B230FX...it currently has the standard cam (VX?) Talking about overlap, I'm wondering whether a different cam would be more suitable for the low-boost supercharger? Thoughts?

volvodriverman

A Cam gets my vote.

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