Supra Forums banner

1 - 8 of 8 Posts

·
Registered
Joined
·
121 Posts
Discussion Starter #1
I noticed what I think is a mold number or something on my head from a 88 N/A. Its a number 9. The redone head I am looking at has a 10. Are these revisions or N/A vs T heads. I was under the impression the only difference was the cams.
 

·
Dr Wheelspin Rh.D.
Joined
·
4,393 Posts
N/A and turbo heads are the same. There are two known different 7m heads, early and late. The difference you can see by looking into the intake runners.
 

·
Registered
Joined
·
121 Posts
Discussion Starter #3
So the 10 is just a revision of the older head (my 9) so the 10 should flow better...thanks for the info bishop...as always you came through.
 

·
Dr Wheelspin Rh.D.
Joined
·
4,393 Posts
Hrm, couldn't find the old picture I took of the differences so I'll just have to post this pic:



Early style is on top, the divider comes much closer to the edge of the head and is a bit thinner. On the later style the divider sits very far back and is thicker.
 
D

·
Guest
Joined
·
0 Posts
I've flow benched both designs. The "big port" flows 10+ cfm more in the upper lift area .400 and higher. At that point it jumped way out on the other design. To take advantage of that you need a cam with a 11.8-12.5mm (about .400 and higher) lift. Our cams at best are .300-.350 stock and regrinds. There are larger lift cams but they come with a large price tag.
 
W

·
Guest
Joined
·
0 Posts
there are probably different numbers for each design... i work in casting and i know that some of the same parts have up to 5 different molds... all identical except for a number.. that way they can re-coat or repair them while still running some.. i dont know if honda motor mounts are the same as a toyota head but its possible.
 

·
2JZ Mk2
Joined
·
1,183 Posts
I have a #11 off a Jan '90 Turbo that looks like the bottom one. From what I've heard they go up to 15. The #s are probably the batch # from the foundry would be my guess.
 
1 - 8 of 8 Posts
Top