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B21 head on B230 block? 200

I've got a good, complete B21f head with cam and a good., complete b230 crankcase.....block, pistons, oil pump, crankshaft, distributor...I want to build a good engine for a 1976 model 242. The body is great. I'm wanting to use existing parts that I have to put this together. All of the parts that I have are within factory spec. I want to use the b21f head so that I can use the CI fuel injection that is presently on the 76 model 242 if I can use the b21f head on the B230 block. My daughter melted a piston on the original b21 engine, but the head is Ok.....I had it checked. I know that the cylinder bore is slightly larger on the b230, but I figure a b230 head gasket should work ok. Any comment or advice? Thanks Steve.








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B21 head on B230 block? 200

the pcy system is different, also. gonna have to re-engineer, re-route that. the b21 had the vent in the oil cap.








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B21 head on B230 block? 200

I know that the b21 head will mate to and bolt up to the b230 block. The water and oil passages in the b230 block are the same.....same size and same location
as the b21 head. I know this because placing a b21 head gasket on the headless b230 block clearly shows it in real life. The only real....game changing difference is the approx. 1/8" diameter increase in cylinder bore verses the b21. I think that using a head gasket for the b230 will do two things....fit up and work...and also protect the edge of the head gasket inside the Cylinder. If I used a b21 head gasket, there is a chance that the edge of the gasket would extend into the combustion chamber. This would lead to a very short life for the head gasket. All that I've said is strictly speculation, other that the head gasket actually fitting, so this is a new application that I've never tried. I'm having the b21 head checked at a machine shop that specializes in engine heads as we speak..

Thanks for the responses
Steve








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B21 head on B230 block? 200

Hi,

Yes, you will have to use a head gasket made for the block itself due to the crushing ring around each cylinder.
Those have got to get sandwiched by the B21 head.

A ledge sticking into the combustion chamber would collect deposits and bring on hot spots.
That’s one thing you don’t want is a “John Cash’s” Ring Of Fire!
The gasket ring would disintegrate very shortly.

Since the B23 bore is larger than the upper combustion chamber the flow is reduced slightly or even concentrated into a smaller space.
With that said I believe the performance is staying the same as a B21 engine would.

Im curious on how much was the valves different and to what extent that the castings of B23 heads and the later B230 head changed internally.
It seems to me that 50cc per cylinder had to mean breathing port tuning was on the design plate, to warrant the cost.

It all doesn’t matter, if it’s all you want is a running engine.
You are not interested in the nuances of power here or there within specific output curves.
It’s the work effort and reusing curve that’s the entertainment here!

Phil








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Let us know if it works NMI 200








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B21 head on B230 block? 200

it will bolt up. my concern is the smaller combustion chamber on the bigger piston. might be premium gas octane or higher when you're done-higher compression.

the canadians got a b23 starting in 81. the airflow meter and fuel dist. were different than the b21, higher air flow. so the b21 kjet stuff will starve the engine a bit.

if i were to try this, it would be an 89 or later block, they're sturdier than the early b230s. good luck, chuck.








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B21 head on B230 block? 200

How about a thicker head gasket to lower the compression ratio?








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B21 head on B230 block? 200

Hi,

That is a very good question, that I have no experience in!
With that said, I’m just going to babble my little head off! ((:))

My first thought is a “big No,” but that doesn’t mean anything.
Most people, like the manufacturers, would make or throw in a bigger engine and wouldn’t mess with it. It doesn’t behoof-them too!
This depends on their prototype research/marketing budgets and the production inventory-contracts.
Easier to zero-in to make another complete model.
Volvo didn’t operate on a two year turn-over like other car makers so I’m back to a MAYBE.

In the following years of Later B230 engines, as a whole they had many changes done internally as far as the moving parts are concern.
This was because they are “hopping up” the engine products all across the board. They cheated on the race circuit, right under the hoods, lots of times!
There was a little racing blood in the veins of the 140 designers and it stayed through the 240 years too! Lots of other car manufacturers were trying to build up sales then. Volvo even advertised about blowing doors off V-8 equipped cars. I never saw it happen, just heard the blabbing mouth!

There is another block that fits in between the B21 over to the B230’s and it’s called a B23. It was an intermediary block and head change out experiment to be supporting of turbos or even supercharger advancement in Europe. Heads and cams shapes galore!

The B21 block just seems to be a more narrow and smaller block in width to me, but that’s only a feeling, as I have no other proof!

If there is any the spread of head bolt pattern, that would be a killer.
Those have to be matching up along with the location of oil pressure, drain back holes and the coolant passages.

The B21 head might have slightly smaller passages but would be irrelevant in your case, since the larger displacement of the engine will not be getting the fuel to burn.
The last two could be a concern with the increase two hundred cubic centimeters of displacement and a turbo being able to create more heat. You are not going that route.
Interesting enough to note though, is the thermostat and outlet pipe is the same throughout all of the displacements. Go figure?
A standard calculation probably was used with a fudge factor already in it as in being “over built,” for the worse case scenarios.
I feel that it was not much of a concern on daily drivers of non turbo or even turbos, because there a “clause or disclaimer” in “all warranties” about “racing” production made vehicles.
Even when you buy a Corvette new!
It doesn’t appear that much was done to the original castings, if you gage the overall look, of all the red blocks!

You are right to think that the injectors have their slight differences but they are basically in the same place and angle aren’t they?
I would wonder more, if a B230 head could be modified to accept the CIS injector bodies.
As I remember, the injector itself is quite thin or is very similar to the electronic injectors diameter, but only have larger upper bodies, up higher, for the electric coils.
You know that the B21 head utilizes a phenolic holder. The idea was to isolate it from heat of the head.
You can see, later on, those things went bye bye as not being needed starting with the B23 LH’s, in or around 1984.
Something to “ponder” about fitting up the CIS into a B230 head?
You might want rethink things into making your holders of the CIS system, fit into a B230 head.
That head, that “righteously” fits the B230 block!
The B230 block and those heads are going to be lot more plentiful, as time goes on, if not already.

I know you realize that the B230 block is going to have a B21’s head breathing capabilities by staying with this idea?
The mixture controller of the CIS will see the more air flow from a slower physical moving engine at idle.
Does the 1976 have a LambdaSond oxygen sensor?
Is it going to self tune like the 1978 GT’s had on their B21?
Yes, the engine block is capable moving more air but as a normal daily driving performance requirements come up, it’s going to make the same B21 power with more or less torque being noticeable.
I don’t know that the mixture will be that much leaner for any reason except on a cold startup? The mass of the engine and the air flow may be slightly leaner then.

I imagine the Various B230 blocks have pistons with different part numbers. For sure with minority a diameter changes or complete design changing all by itself.
I think the B23 to B230 block had a stroke changes with the crankshaft rods and journal width movements.
It’s a lot easier to get more displacement with a Length of stroke change. You change torque and rev-up characteristics too!
The distance from the top of the piston to the wrist pin center can be adjusted along the way with its diameter those numbers changing along the way.
If the top of pistons themselves stayed the same in regards to the “deck of the block” and could give way to a possibility of this area working out.

This sure was a lot to think about and babble about! Whew?
I hope I made some sense of it and you can tell us what you find by measuring things out, carefully!

Phil







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