Carburettors for B18 + K Cam ?

[Vintagewrench]

Originally Posted by sleek lemur

Many thanks, Vintage Watch. What size SU do you use?

sleek lemur - HS6 - 1-3/4"

On a completely different subject next season due to a cam change and cylinder head improvements we are going to use this set of Volvo Competition Service Solex 45 ADDHE carbs and manifolds.

[142 Guy]

Originally Posted by Derek UK

123GT spec used a C cam. That was their best standard cam with carbs. D came along with the D-Jet F.I. and the K with the follow up K-Jet. K cam design slightly improved emissions, the regs for that getting tighter at the time. Very slightly less lift than the D and with less aggressive lift pattern. It's reputed to run slightly quieter and smoother than the D. Both perform better than the C cam.
If the smoother quieter running is true it may be a better choice as on the road I doubt if you'll notice much difference in normal day to day driving. Not saying that you couldn't tell the difference if you back to back tested identical cars whose only difference was the camshafts. Both have their fan clubs.

The wisdom of the internet suggests that the lift of the D and K cam are the same. This reference

http://www.1800philes.com/ianr/_superlist_grinds.html

suggests that the primary difference is in the initial opening and overlap. The timing of the 0.050" lift suggests that the cams are pretty much the same after that. I believe that the initial exhaust emission limits in the US were all about checking compliance around idle speed. The marginal reduction in overlap on the K cam probably helped to bring the B20F into compliance at low engine loads.

Since Euro and GB emission regulations lagged the US I know that the B20E was available on the east side of the Atlantic after 1971. Did the K cam come into use on the post 1971 B20 cars with D jet and K jet or did they continue with the D cam?

[Derek UK]

Yes I'm aware of that cam list and should have looked at it before posting. I've also read that it hasn't been updated for a long time and that there's some anomalies in there. I can't think that Volvo would have kept the D cam for the K-jet in Europe, especially for the small number of units needed. There were also some C.R. changes, down, I've not looked at those either but they probably suited the K more than the D.

[sleek lemur]

Thanks all for really interesting replies.

Vintagewrench, sorry about getting your name wrong. I have a friend with a business called Vintage Watch!

I'm waiting for information from Brookhouse and will be sure to pass it on.