Tunning the B172K

Post by **340cbr** » 23 Nov 2005 04:08 pm

I have a bought in September 340 1.7 with the B172K engine, eith the solex carb.

The only change that I have made was to put the solex carb from an Volvo 440 GL, and I notticed some differences.

But I want a little bit more...

I'm thinking in changing the cylinder headby one from a Volvo 400 1.7 injection model, with injection ports blocked. This will made the compression ratio increase from 9,5 to something arround 10,5 I think..
Will it really made some difference? And the other parts of the motour won't fail with this change?

And changing the current air filter by a performance one? Some guys told me that the only difference will be in the sound, because this is a carb motor...

I expect some replies here that can help me!

Thanks!

Post by **340GLT** » 23 Nov 2005 05:33 pm

Well on mine i changed filter and exhaust system from axle back and noticed a considerable change. At a later date i rebuilt the weber carb and this improved it again. The trouble with adding a performance filter to a carbed car is you lose the hot air feed and get problems with carb freezing.
I solved this prob by building a custom box for my filter with a hot air feed like this!
Cheers Adam

Post by **Japper** » 23 Nov 2005 05:39 pm

Is your 340 faster than a 360 you reckon? Do you notice a big change with that strut on the shocks?

Post by **340GLT** » 23 Nov 2005 05:43 pm

I wouldnt go as far to say its quicker than a 360 but its definately quicker than my 1.7 and my grandads 1.7!!!
As for the strut brace i reckon it helps to tighten the front up because now you get more front tyre squuel as apposed to understeer.
Cheers Adam

Post by **340cbr** » 23 Nov 2005 05:50 pm

Whell.. I think that i'll not have problems with carb freezing here in Portugal

Your mod is interesting... You mantain the air intake in the front of the car. But it's not very simple to do

You have changed all the exhaust system? Do you have some photos?

Your had the weber carb? What consist in rebuilding the carb?

Thanks

Post by **340GLT** » 23 Nov 2005 05:58 pm

Well the weber carb is because mine is a 1.4.
The only exhaust pics i have are in the link below.
No i changed the exhaust system from the central silencer back.
The carb itself was a full strip down and rebuild with a different accelarotor jet from an earlier weber.
Cheers Adam

http://www.volvo300mania.com/forum-uk/v ... -f1394.htm

Post by **classicswede** » 23 Nov 2005 11:14 pm

When I still had the 1.7 I put a full exhaust and modded manifold and sports cleaner on. These mods do make a big difference and are a good step to getting a bit more go.

If you want to go further drop in a B20F from a 460. My car now goes like stink

Dai

Post by **foggyjames** » 24 Nov 2005 02:39 am

Agreed - if I had a 1.7, I'd be running an injection engine from a 400 series car, probably the 2.0.

cheers

James

Post by **340cbr** » 24 Nov 2005 11:56 am

That's not an option to me for 2 reasons:

- 400 were not sold with 2.0 motors here, only 1.6, 1.7 and 1.7 Turbo.

- We pay a tax calculated in the displacemente of the motor when we bought the car... If I put a 2.0 in it I'll had to pay it the difference like it were new and come with the 2.0 motor....

Post by **foggyjames** » 24 Nov 2005 01:33 pm

How about the 1.7 then?

I'm fairly sure it gives better performance than the 1.7 carb, especially in terms of MPG.

cheers

James

Post by **volvorsport** » 24 Nov 2005 02:34 pm

so fitting a 1.7 turbo is possible ?

Post by **340cbr** » 24 Nov 2005 04:32 pm

Well.. It's possible but it give a lot of job.

The motor in the 440 is in transversal position. It's needed to change all the admission and exhaust systems

Post by **volvorsport** » 24 Nov 2005 04:38 pm

youre only other option is , a rebuilt motor with HC pistons and worked head with progammed fuel injection or twin carbs .

i think going over to megasquirt would be a good idea , gets rid of pesky carb problems , allow a much better manifold to be used .

Website · Post by **antiekeradio** » 24 Nov 2005 08:28 pm

a 1.7 injection is not necessarily better on MPG than a carb version....

The only change that I have made was to put the solex carb from an Volvo 440 GL, and I notticed some differences.

---> you should change the main air and fuel jets to the ones from your original carbs! it will get good MPG again!

Post by **classicswede** » 24 Nov 2005 09:03 pm

Well it looks like after exaust and induction you will need to do some internal work.
I'm sure you can get some bigger valves in there combined with a hot cam should give some good results. There are a couple of points in the ports that just need a little clean up to aid flow.
If you are going to rebuild the engine bore it out and stick some oversize pistons in while you are at it.

If it was not for gas I would stick with the carb set up.

Dai