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B21+T - T3 and Breather options

J

Jaypee_6680

New member
Joined
May 18, 2019
Location
London
Morning TBers.

I?m currently undergoing a +T conversion on my 1975 245DL, and have a few questions about the turbocharger components I?ve bought, and their compatibility with the B21 which I?m struggling to find via a search.

I bought a complete B230FT from a 1990 740 Turbo, which unbeknown to me has a Garrett (T3 by the looks of it) turbocharger rather than a TD04, which appears to have had the CBV removed, therefore running straight Air filter - MAF - Turbo inlet.

I?ve solved most of the compatibility issues (in my head at least) with the oil feed/drain, CPS and knock sensor, but have the following problems I?d like some advice on.

CBV
- Can the T3 be run safely without a CBV? It needs a re-build currently and I wonder if the lack of CBV caused it to fail.
- What does the Garret T3 external CBV set up look like, how is it plumbed in, and what parts would I need to fit one?
- Does anyone have these parts available?

Breather
- My B21 is an early type with a rocker breather only. Is this acceptable to use in a +T conversion by plumbing it into the intake, or do I need some form of block breathing for +T?

See pictures below for the turbocharger I have.

open

open

open


https://drive.google.com/open?id=1Sk7ypFRRKGJkb6kdXj5hlW19WILVhgRJ
https://drive.google.com/open?id=13_fJSsHaY2o7rkeOjjWFW99Qvv-ePFhL80YCI1Iulig
https://drive.google.com/open?id=1XbU_PcN9wkuP79b84toRKSqxSOjoSkxl
 
They used what's called a Pierburg valve, I have one on my 780, I have an extra valve but not the plumbing somewhere. I got the hoses for it for cheap off of Rock Auto.
For my B21+T I got a catch can off of eBay and plumbed it in. I have it hooked up to my intake pipe.

It's hiding under the lock support panel. I'll try to get a better picture tomorrow too
https://photos.app.goo.gl/ALBTryieRQp4dV3V9
 
If you'd like to keep it simple add a catch can to the breather line and and connect it right in front of the turbo, 90% of the oil will stay in the can and you wont need a check valve because there is never any pressure. Myself i wouldn't route it back to the engine at all but vent to atmosphere to keep enigne, intercooler, piping and sensors clean of any oily buildup. Downside of this method is that the fumes wont be burned and exit out the exhaust but come out on the front, So when idling in front of a red light you might smell a slight bit of oil. How much will depend on engine health.
 
Any particular reason why we aren't swapping in the complete b230ft and are keeping with a plus tee on the b21?
 
My first experience with needing enhanced crankcase breathing began with my stroker B26FT 20 years ago. Took it long distance to a volvo meet and discovered during long uphill grades while in boost oil was burning on my exhaust, causing smoke I could see in the mirror. I eventually figured out oil was being pushed out the rear main seal under prolonged boost. That was with a mostly stock breather system.

So then I opened up breathing as much as I could with an extra port from the valve cover. Never had the issue again. Never went with a catch can on that car.

With my current car I did go with a catch can system. Everyone on here who has done anything like this has their own opinion on the *right* way to do things. So you can absorb that and do what you think works.

My current setup uses mostly Yoshifab components and can be seen in my page:
https://www.240turbo.com/volvo240mods.html#catchcan
Dave B
 
kyote said:
Any particular reason why we aren't swapping in the complete b230ft and are keeping with a plus tee on the b21?
Click to expand...

Mainly because I like a hard time!

My car is one of the oldest 245's in the UK, and a nice example so I'd like to keep it as original as possible. In the UK we have the engine numbers, and cubic capacity listed on the ownership documents too, which I'd like to keep as Volvo intended...

They used what's called a Pierburg valve, I have one on my 780, I have an extra valve but not the plumbing somewhere. I got the hoses for it for cheap off of Rock Auto.
Click to expand...

Ah ok. Does anyone have a Volvo digram of this set up with part numbers etc?

And what would happen if I didn't run one?

Good info with the breather, I might just hook the current one up to the intake and see how it goes!
 
Jaypee_6680 said:
Mainly because I like a hard time!

My car is one of the oldest 245's in the UK, and a nice example so I'd like to keep it as original as possible. In the UK we have the engine numbers, and cubic capacity listed on the ownership documents too, which I'd like to keep as Volvo intended...



Ah ok. Does anyone have a Volvo digram of this set up with part numbers etc?

And what would happen if I didn't run one?

Good info with the breather, I might just hook the current one up to the intake and see how it goes!
Click to expand...

Righty O!

As far a s a CBV, look for a SAAB turbo at your local... breakers and snatch that one.
 
My original '85 B21FT intercooled KJet engine included an oil+water cooled T3 turbo, and the '82 B21FT non-intercooled engine I bought to rebuild also included an oil+water cooled T3 turbo. Neither one had a CBV or BOV. Seemed to be OK with Volvo to make them this way, but a CBV/BOV should be an improvement, and they were included in some of the 740 T3 cars. I now have a 15G, with built-in CBV, on the rebuilt B21FT engine.

Pics of '85 Tic T3 and '82 non-ic T3 (click on pic for full size):


 
I have a Pierburg CBV, 90 degree elbow (1st pipe outta the turbo, this has the return hose nipple thingie from the CBV, this is different than any other Volvo pipe) and bracket if you decide to go that route. The bracket also fits many 2 bolt flanged CBVs, I had a Greddy Type S on it. The bracket and elbow I have are powdercoated in candy blue.
 
Anybody install baffle in valve cover. Always seems like I get oil seeping from valve cover cap. wither it’s vented cap or not. I’m about to add turbo. So I’m gone cut another hole in valve cover and weld baffles in them.
 
Try a new valve cover cap gasket, it's like $3 or something. If it still comes out you have another serious problem. You don't need a baffle, and next time start your own thread if you have a question please.
 
6.5psi doesn't need a recirculating valve. The valve in the throttle plate helps. But the intercooled 740 engines ran a bit more boost so Volvo added the pierburg valve at first. Then in the late 80s went to a built in valve on the turbo.

I used the turbo outlet pipe from a T3 on a 740 to add a Forge valve made for Saab. Next time I do this I am going to add the valve inlet to the cold side intercooler pipe. That is where the group A cars used a recirculating valve. The outlet goes to the turbo intake pipe.

Check out Stealthftis method for adding breathing to the engine. https://pbase.com/stealthfti/pcv
 
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This is all super helpful thanks.

My B21 has no block breather system (or casting for it in the block) as it's an early type.

Thoughts on creating a custom block breather by tapping the oil pump cover plate and running a hose to a catch tank?

John
 
The other place people vent the block from is the mechanical fuel pump cover plate. With that block vent and the valve cover as stock. That would provide good crankcase venting.
 
Yeah, mechanical fuel pump hole could be a good spot to connect a breather. Or make a hose coupler on the oil pump cover.
For a catch can I'm using a mann provent 200. Works great, has a valve to prevent excessive pressure if something freezes shut etc. Turbo stays clean now. Aliexpress has them for cheap.
 
I don't have any problem venting through the stock B21 valve cover hole and I'm running 24psi. I actually tried making something that bolts on the mechanical fuel pump cover but got too much oil through it. I don't think I mentioned that I use an HKS SSQV valve in an adapter that goes in the piping that I got off eBay. I don't recirculate it either it just blows off into the engine bay.
 
11110000 said:
Take a look at your throttle butterfly - Volvo put a crude, spring-loaded "blow-off" right in the throttle plate on the early cars.
Click to expand...
Thanks, that's interesting. Here are some pictures (click for bigger size). When open, there are 3 roughly 1/8" slots under the spring valve. Not much area for pressure relief, but I guess that it's enough with the base idle air flowing around the plate plus whatever the Idle Air Valve adds, if any, when throttle is snapped closed.

 
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