• Hello Guest, welcome to the initial stages of our new platform!
    You can find some additional information about where we are in the process of migrating the board and setting up our new software here

    Thank you for being a part of our community!

B21/B23 Questions

Status
Not open for further replies.

ybotspawn

New member
Joined
Sep 4, 2017
Ok, so color me noob but I couldnt help notice that the redblocks that come in these cars are semi closed or closed deck? That little nugget sorted in my head, I'm thinking about a project of building one up. Am I correct to assume a redblock out of an 87 would also be a closed or semi closed deck? This is my wifes fun car so I was thinking a little td05 turbo and e85, but I'm open to suggestions. The current motor is fine, just a little project for me to work on in the new year. Would a 1987 redblock meet those requirements? If anyone has some suggestions, I'm open.

Matt
 
If your not replacing the rods, you're probably better off with a B21/23. Or a late model B230. The 87 has pretty weak rods, and I assume that with a td05 and e85, you'll be throwing a decent amount of boost at it.
 
If you are making average hp (250 or less), you're fine with your existing motor.

Want to run 9's, more is required.
 
Thanks for all the info. So in terms of this project its a couple fold. First, Ive never built an engine and would like to take it on as my little project in 2019. I don't want to modify the stock motor in the car, hence the purchase of a new motor. This is my wifes fun/daily car, so I'm trying to do it right but with a little bit of a fun angle. I'm looking at replacing just about everything in this new car. Not because I want to run 9's but so I can get a better grasp on whats going on. So with that said, and knowing I have a b23, I'll continue perusing the forums. I'm mentally mulling the idea of 16v conversions, compression ratio, valves etc. Any advice anyone has I'm definitely open to hearing
 
Can be you a bit more specific? Like power goal? Handling goal? You mention this is your wifes car. So are there also comfort levels to consider? A stock volvo with IPD bars on it can be called a fun daily.
 
This is my wifes fun/daily car, so I'm trying to do it right Any advice anyone has I'm definitely open to hearing

2pgcdb.jpg
 
You guys are funny, @Redwood Chair. Yes this is my wifes car, but she also has a daily driver subaru forester. We bought this 242 gt because she had one when she was growing up and loved it. She wanted a classic car that she felt safe having our son in. With that said, I'm not looking for crazy power. Hell I'm not even thinking about rebuilding the stock engine. I'm looking at performing this little task, because I'd like to learn how to build a motor, and because the 242s are pretty underpowered.

Power goal? Over 200
Handling goal? Close to stock, nothing radical
Speed goal? Immaterial
Learning goal? Engine build with design considerations around a smaller turbo charger
Optional goals? Better understanding of cam timing with an introduction of a 16v head
 
You guys are funny, @Redwood Chair. Yes this is my wifes car, but she also has a daily driver subaru forester. We bought this 242 gt because she had one when she was growing up and loved it. She wanted a classic car that she felt safe having our son in. With that said, I'm not looking for crazy power. Hell I'm not even thinking about rebuilding the stock engine. I'm looking at performing this little task, because I'd like to learn how to build a motor, and because the 242s are pretty underpowered.

Power goal? Over 200
Handling goal? Close to stock, nothing radical
Speed goal? Immaterial
Learning goal? Engine build with design considerations around a smaller turbo charger
Optional goals? Better understanding of cam timing with an introduction of a 16v head

Where are you getting an 87 engine from a 242? 242 should have a b21f IIRC, with a B cam. Very stout bottom end. Much much stronger than any engine produced in 87.
 
Where are you getting an 87 engine from a 242? 242 should have a b21f IIRC, with a B cam. Very stout bottom end. Much much stronger than any engine produced in 87.

242 up to 81 had B21
82-84 were B23 in NA form, B21FT in GLT form.

Strong in comparison to what? Even the 'skinny rod' 85 - 89 B230 is ludicrously overdesigned for the power it made stock and then simply overkill till you get to 250+ HP. Yes, the B21/23 motors were even beefier, but in the end overkill is overkill.

At 250HP, you are at 1.75 HP/CI. Even David Freiburger from HRM would respect that level of performance. In stock form, a B21FTi was over 1HP/CI.

To make it into the 300+ hp club (and be worried about the skinny rods at that point), you are over 2HP/CI. In an old school 5.0, you would be over 600HP at that level of performance. You would probably blow up the 5.0 after a while at that HP as well.

The fact of the matter is that we are spoiled. All of the B21/23/230 motors are so beefy out of the factory that we have gotten used to being able to beat them up for hundreds of thousands of miles and get away with it.

Build which ever motor you have. If you are around 200hp at the wheels, have fun and don't worry about doing anything special with the short block. Any of them will be just fine. If you want a 'fun' motor, buy some decent lighter weight rods and pistons. Doing that WILL make it more fun - and free up a little HP.
 
quillics post is actually part of the reason, I'm doing this on a volvo motor. Notably a b23 or a b21. I come from subaru world (wrxs and brzs are my daily play toys). I know enough about cars to be dangerous. My wife has wanted a volvo 1980 242 gt for a long time. When I found one I was simply happy making her happy. Then I found I was gifted a ton of parts and literature. I don't know what they are called but I have a full collection of the green binders (Yes I'm sure I'm basterdizing that). It took some perusing through them to note that they are closed deck. Even the modern wrx's aren't closed deck. This immediately stood out to me as a motor that could take a beating (whether from power or my stupidity). You guys are really spoiled. Thats a rarity.

@PromiseRing - Yes it's a b23 I'm buying. The b21, currently in the car, runs just fine. I have no intention to modify it from stock form. As stated, the goal is to build a 200+ hp motor and do some learning in the process. The benefit to this platform is that its not the wifes daily (though her sentimental connection to this car encourages her to make it her daily). Thats where the original question began, what is a moderate build, that is reliable enough for daily duty. I have a local volo friend who is also interested in helping me and so far we're at the following:

b23 block
b234 heads
Aftermarket rods
Haltech fuel
~ not sure on piston compression yet
~ not sure on which cams yet
~ not sure on which turbo, but currently leaning toward an IHI or some other small one of similar ilk for quick spool

We're planning on fabricating turbo and intake manifolds and assembling the rest, after tearing down the b23. The fact that I can buy a large portion of these parts for the price of my wrx's exhaust is simply astounding to me. You guys won't make me a full on volvo fan boy, but I do look at the old bricks with a completely different level of respect than previously.
 
242 up to 82 had B21
83 & 84 were B23F in NA form, B21FT in GLT form.

Fixed.


NB:

The B23F came in a slightly lower compression variant in the 84 stick shift cars, and the B23FT was a one year one car engine found in the 84 760 with a block mounted distributor and forged internals.
 
Based on what?

Use your ****ing head. I’m talking about redblocks because this is a primarily redblock forum. Yes, the b21 IS in fact much much stronger than the 85-89 redblock motors. They had M rods which even JohnV respects. Yes, you can have fun with the skinny rod motors, no one is denying that.

Now off to back to off topic where you belong.
 
Last edited:
Use your ****ing head. I?m talking about redblocks because this is a primarily redblock forum.

Well, that's not what you said, you said:

Very stout bottom end. Much much stronger than any engine produced in 87.

Maybe you should be more careful in your choice of words in order to avoid confusion.

Yes, the b21 IS in fact much much stronger than the 85-89 redblock motors.

How exactly?
Do you have numbers?
How do you interpret those numbers?
What do you compare those numbers to?

They had M rods which even JohnV respects. Yes, you can have fun with the skinny rod motors, no one is denying that.

I don't know what you are ranting about at this point.

Now off to back topic where you belong.

What is back topic?
 
Status
Not open for further replies.
Back
Top