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...

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

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.

Spac

The kit was originally paired with an A cam.

Back a million years ago, the A cam was considered to be the best factory performance turbo cam - but I don’t know if the people saying that had actually used the bigger cams or simply dismissed them as being “too big” without trying them.

I have seen people be happy with K & H cams in drag cars, don’t know how they’d go in a useful car.

volvodriverman

I've tried the A, K, D, VX, T and V in a stock 2.3 litre turbo redblock and the V is my pick of the factory cams for that application followed by the A. VX goes flat after about 4K, T is just meh everywhere, D is similar to T but a bit better all round, K was good up top but a bit sluggish until 2-2.5K.

Still prefer the KG2T to anything else I've used and it behaved well in a stock b23ET.

Major Ledfoot

volvodriverman
I've tried the A, K, D, VX, T and V in a stock 2.3 litre turbo redblock and the V is my pick of the factory cams for that application followed by the A. VX goes flat after about 4K, T is just meh everywhere, D is similar to T but a bit better all round, K was good up top but a bit sluggish until 2-2.5K.
Still prefer the KG2T to anything else I've used and it behaved well in a stock b23ET.

So much for less overlap = better +t performance. Real world experience beats theory again.

volvodriverman

Does what it says if you do what they say.

ramrod

Every engine oil contains zinc

If it didn't, engines wouldn't last longer than a few miles

jamesinc

I think I'll go with an A cam as it has been recommended the most out of all the options. I may upgrade to a KG2T later on but I'll roll with the OE cam for now.

So I did end up using a B21 gasket, but an Elring gasket. The first gasket I tried was a Pro Parts Sweden gasket that I had been using to mock stuff up. I don't really like PPS as a brand, but I accidentally ended up with a gasket set from them so I've been using them when mocking stuff up.

Anyway the PPS gasket has circular openings for the chamber, but the Elring gasket has openings that are shaped slightly to give more clearance for the chamber wall, and as a result it fits perfectly.

Fresh set of head bolts because I have at least two good sets in the garage but I can't find either of them:

And finally the head and block are united:

I'm waiting on a bunch of parts at the moment and trying to sort out the turbo housing so that I can send all the cast pieces out for ceramic coating.

So, it's very much still happening but expect to wait a couple more months for the final product :)

jamesinc

Okay, all the turbo parts are ordered, I think the only large cost left now is the exhaust system, which will be a 3" downpipe, resonator, down to 2.5" and a turbo rear muffler. I think I'll spring for stainless, and I'll move the current IPD stainless exhaust to the other 244 I have.

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