OK, OK, I blew it on the James Dean thing. I don't know where I got that
in my head. But the idea was right...
Someone asked where they should install a heat shield- on the starter or
manifold. A: neither. A heat shield will work best if there is an air gap
both sides of it. Sorta the way triple pane windows work, with an insulative
layer on each side of the center layer. Mount with some kind of standoffs
from either surface.
Zahid asks:
> I just ordered a full engine rebuild kit for my Spitfire
> should I put oversize pistons in?
Oversize pistons require an oversize cylinder bore. If the bores are ok
now, then use stock, If you need to have it rebored, then you'll have
to fit oversize to match. (ie: bore .010 over, fit .010 over pistons)
Unless you're building an all out competition block, there's no reason
to overbore just for to get a bigger bore. A light honing to break the
glaze (smoothed, hardened cylinder wall surface) may all that's needed.
All this is found out after you take it all apart, and inspect and measure
all the bits. Someone may have already done things in there, you won't
know until it's apart.
Sam sez:
>I'd like to get my hands on a couple/few '71 MGB heads (mate
>to an 18GK engine). The specific model year/type is due to
>racing rules that say that I may update/backdate only
>"complete assemblies", and an engine/head combo is a "complete assembly".
>I've been told that the 18GK is probably
>about the best MGB engine (note that I'll be balancing and
>blueprinting this engine), partly due to its having full-floating
>wrist pins; any counterviews out there?
I know which is the worst! Brain-damaged 18V's! Even before the single carb.
There aren't too many differences between 18GB-GK heads. The ports were
added for the polution control manifold starting in '68 (GC-GF?) I have
18GB's, a 18GF, 18GK, and 18V. Early 71 had GK anyhow. I don't know if
the head had any real changes for the 18V. What I'd really like to find
is a chart showing all cam/valve/piston changes, etc. The Bentleys
and B-Series data give some of this, but spread out.
(I'll try to remember to check the casting numbers. You may be able to
get away with swapping in that range of heads, if they all look the same.)
18GB's (65-67) are often mentioned as being the favorite. This is the
pre-polution version. I've been having a hard time figuring out the
real diferences in the later versions, other the cam and distributer
change for the 18V. And changing to black paint instead of red at GK or so.
(anyone got specs on cam profile/timing differences? I haven't found these
at all yet.)
________
/___ _ \ Roger Garnett (garnett@tcgould.TN.CORNELL.EDU)
/| || \ \ Agricultural Economics | The All New:
| |___|| _ | 3 Warren Hall | South Lansing Centre For
| | \ | | | Cornell University | Wayward Sports Cars
\| \ |__/ / Ithaca, N.Y. 14853 | (607) 533-7735
\________/ (607) 255-2522 | SAFETY FAST!
|