13sr head

[novatracker]

iv got 2 gte heads a 14sr and my old 13sr head sitting spare whats the best head and cam ta use? whats the best after market cam 2 by and how much? how much could i get a Blydenstien head 4 and whats the bigest ports on them. iv using a 1300 sr with 4-branch, webber 32/34 and a k@n at the moment. plz help.

[david dixon]

the early 1.3 heads where the best cos they had the biggest valves!

[johnny27]

As far as I know the 1300 heads DID NOT have bigger valves the only heads with bigger vavles where the 1.6 gsi/gte and 1.4 Sri. But the 1300 head is alot better for tuning because there is alot better flow because of the good port design, the 1400 has little square ports very restrictive.

[Snowface]

a 1200 head is slightly better still than the 1300. Ports are same shape but flow is slight better and valve seat area is better. (according to Bill Blydenstein).

[MC]

If you plan to use one of the heads unmodified then use the GTE (skimmed to the correct compression), if you are going to have the head modified then it doesn't matter if you use the 1.2 head as the head will all accept the same size valves. Don't get caught up in the A, B, B+ talk, just tell Bill you want the best head with no compromise and he will fit the biggest valves that will fit the head. A B+ 13sr head will still have smaller valves than a B+ for the GTE, so ask for the biggest valves!

MC

[Snowface]

mine's a 1.2 head B+ & 1/2.

he used 36mm inlet valves instead of 35mm cause he had some low millage ones left over from a VX Monza head he worked on. :D

The B++ is the ultimate though i think. Look a Jim's as an example. to get 169bhp (or is it 179 :?: ) from an 8v head is good going. A testament to Bill's work some might say.

[MC]

Bill has NOT got a B++, fact. You cannot go further than a B+ as 1mm larger valves is the maximum that will fit. I further modified a few things on it.

You can have a B++ on smaller heads like the 1.2 and 1.3 as the valves are smaller to start with.

Bill doesn't actually talk in terms of B++ anyway. Talk to him properly and he'll give you real world advice and details.

MC