Location: townsville NQLD
Registered: February 2004
Re: Yamaha 88270 head Technical info
Mon, 06 September 2004 09:43
you should try doin a search because there is quite a bit of info on these heads.
this is what witzl posted a while bak
Quote:
Here's some head numbers off Al's 18RGs:
> 88250:
> - 49657 single spring early rgu single dump ex ok head small studs on ex
> - 52978 same as above
> 88253:
> - 73086 double spring late rgu good head to start with large studs on ex should be duel dump man
> - 62744 single late rgu still good head may be small stud ex should be single dump
> - 81784 double spring late also
> - 87278 double spring late also
> 88270: these are ale efi heads all double springs alll good heads these are the ones you use
> - 35140 biggest ports biggest valves no smog ports best casting
> - 08037
> - 49383 very late head newest ive seen
> ?:
> - 81225 same as above double late rgu if the head is a 11111-88253 not a 11111-88270
> 88253 88270s would be the heads of choice since these need very little work from the factory these willl make lots of power with little porting they will make a lot more power with a lot of porting the castings are a lot thicker around the ports so there is a lot of room the 88250s can be made good but the ex studs should be changed up to 10mm ones for best sealing all of these engines should have 8.5s to 1 but the efi 88270 heads they should have 8.3 to 1 just be glad you dont have any of those 11111-88230 or 88210 heads they are good paper weights.
Hope this helps your info of what you got there sounds like my garage
Hmmm... not sure about the comment regarding the 210 head being a paper weight. Early build 18RG with carbs and 210 head had the highest compression ratio (9.7:1) and produced the most HP (145hp) in stock form.
The later heads were required to compensate for lower octane feul and EFI. These engines, in stock form, could put out 115-130hp.
Yamaha 88270 head Technical info
Sat, 04 September 2004 00:55
