Engine: 2.3 Carb B23A/B230K: B230K engine conversion to B230FT

[Glen Morangie]

Originally Posted by EYB

What is the best combination should I decide to install the dual carb system?

Surely it will depend on what manifold you can get - other than that for 'fit and forget' reliability Solex or SU, for performance Weber, but I doubt you will have much choice.

[Suterman]

If you really want to use carbs and a b230ft I would suggest it would be possible, but I really dont know enough about these things to say.

The trouble is you wont be able to just fit the pistons that you have ordered as you need to check the cylinder bore sizes and the piston size and stuff like that.


Mike Brace is talking a lot of sense.

"Whilst it is possible to build up an engine and management system out of various bits and pieces it is fair easier and will cause far less problems to be able to transfer a complete good running engine and gearbos complete with its management system and wiring. For a start you know that everything is working before you start the project and know any problems have to centre around mistakes made on the wiring side of things."



If you find a nice b230ft you could remove the inlet manifold and put your penta inlets and carbs on, you would need to make a plenum chamber thingy to go over the carbs, you may also have to adapt the carbs to the inlets using a plate.


like this guy...


http://forum.savarturbo.se/viewtopic...ressor&start=0


Theres 4 pages there with some pics, I think it is a budget build due to the fact that he had a b23ft motor and some carbs lying around or something like that.

Theres some crazy builds on that site.

[EYB]

Hi Glen

I got hold of an original dual intake manifold from a 240 marine volvo engine with a dual Solex carbs (requires reconditioning). Regarding the CR of my existing engine (B230FT head on stock, original B230K pistons/block), assuming the FT pistons/rods have the same specs of the K pistons, is it wise to change the pistons/con rods? What would be the final CR if I do the switch? I understand that the CR of the FT engines are lower than the normally aspirated engines such as mine. Am I better off with the existing set-up and just add the dual carbs? I want to use the best combination of higher CR with the dual carbs.

[EYB]

Hi Suterman

Thanks for the invaluable inputs. I do admire your set-up!. Like what have previously mentioned, in as much as I want to transfer an existing FT engine set-up to my existing engine, this is my handicap. My vehicle is here in the Philippines with very little source of used Volvo parts and I only gain access for good used parts from the US, but definitely not the whole engine.

My options are basically limited to 2 choices at the moment, with my present set-up, add on the dual carbs-Solex or shift into Webers, or replace the K pistons with the FT pistons (assuming they fit) and add on the dual carbs. I want to know which among the 2 can give me a higher compression ratio.

[EYB]

Hi Suterman

I just reviewed the site you emailed and was surprised that IT IS a B230K engine. Which leads me again to the issue of Compression Ratio. B230Ks have a CR of 10.5:1, one of the highest. Turbo models I know have much lower CRs. Can you approximate the computed CR of my existing set-up? B230k pistons on a B230FT head? Will my CR drastically go down if I use the B230FT pistons?

[Glen Morangie]

Originally Posted by EYB

Hi Glen
Regarding the CR of my existing engine (B230FT head on stock, original B230K pistons/block), assuming the FT pistons/rods have the same specs of the K pistons, is it wise to change the pistons/con rods? What would be the final CR if I do the switch? I understand that the CR of the FT engines are lower than the normally aspirated engines such as mine. Am I better off with the existing set-up and just add the dual carbs? I want to use the best combination of higher CR with the dual carbs.

I'm not sure if you are missing the point, or I am - but if you put an FT head (which has combustion chambers) on a B230K block (which also has combustion chambers in the pistons), you will have two combustion chambers combined in each cylinder and a compression ratio of around 5:1.

Is this what you were asking?

[Suterman]

you can run boost on a higher compression engine, just not as much as on a lower compression (ft) engine. The b230k has high compression, maybe 10.5:1 (dont quote me on that)

you could proberbly run 3 or 4 psi of boost with the right tuning on a b230k

To be honest I can't say for sure.

[Glen Morangie]

Originally Posted by EYB

Hi Glen
Regarding the CR of my existing engine (B230FT head on stock, original B230K pistons/block), assuming the FT pistons/rods have the same specs of the K pistons, is it wise to change the pistons/con rods?

I think I may really have missed the point here - are you saying that your current engine (which presumably you were driving around) is a B230K with a cylinder head from a B230FT?

If it is you might get as much performance as you need just by swapping the pistons/ con rods.

[EYB]

Precisely Glen! I bought a junked 240 without the original cylinder head. I was able to find one that fits (from a B230FT) and it is running, but with poor acceleration and engine response, unfortunately the donor FT engine was sold as scrap.

This leads me to my concern of Compression Ratio. With the original 10.5:1 of the B230K. As you mentioned, having 2 combustion chambers (FT and K combined), CR will drastically drop. Now if the FT pistons and conrods do fit the B230K block and finally having just 1 combustion chamber, approximately what will be my final CR?

[Glen Morangie]

I’m afraid I’m a bit confused, as some of your posts seem to have conflicting information (or maybe I’m misunderstanding them).

It seems you first asked if it was possible to convert a B230K Solex CISAC setup to a B230FT, but you later added your B230K in fact has a cylinder head from a B230FT already fitted – retaining the B230K pistons and CISAC carb (and it lacks power).

You have also purchased a Volvo Penta manifold, and may decide to use it with either Weber or Solex carbs.

You then discovered the B230FT engine you planned to swap in was in fact a B21FT, and the associated transmission is manual, whereas yours is automatic.

Later on you said the B230K flat top pistons were installed…….

I think you need to note a few points:

1. The B21 engine uses a different bore to the B23 or B230, so the pistons won’t fit your existing engine.

2. The B230K has a flat cylinder head, the cylinder head has no combustion chambers, instead they are machined into the pistons.

3. B230K pistons are not flat (but you will have seen this when the head was fitted).

4. If you have fitted a cylinder head from a B230FT to your B230K without changing the pistons, because you will have two combined combustion chambers in each cylinder, the compression ratio must be very low, and the engine won’t have much power.

5. The main things which affect the compression ratio are the sizes of the cylinder bores and the compression chambers.

6. If the setup is as described in 4 above, and you now swap the pistons to some suitable for the B230FT (which I think may actually be slightly dished) you should get a compression ratio of 9.8:1.

7. I would think the cost of purchasing a B21FT and shipping it from the USA to then be installed with all it’s associated parts will be far more than buying new pistons for your existing engine.

8. My advice would be as in 6 above, then decide if you want to change the carb.

9. If I were trying to ship an engine from overseas and it wasn't certain exactly which type of engine was being shipped, I'd be looking elsewhere.

10. From the data I've got available (which may not be definitive) I looks like the con rods would be the same, and it's just the pistons/rings you'd need, however the B230K does tend to develop piston slap so you may find uneven bore wear, so best to check that before you order any new parts.

Hope this helps.