Graeme,
IMHO, DON'T cut the head! Roadster heads are too rare and even those that
are out there are often all screwed up, even the cast iron heads. If you cut
the head and your car overheats and warps the head what are you going to do
then?
I would recommend:
Get the block decked. In addition to straightening up the block gasket
surface, it also provides a true squared surface as compared to the
crankshaft. Although Datsun had much tighter maching clearances than
American engines, they could still use a cleanup. It's like shaving a head.
Get the block bored. No substitute for displacement. Go 30 over.
Get better valves. Manley and several other valve manufacturers make lighter
and better valves for the engines. They will let the engine breath better at
partial lift.
Get a hotter camshaft. The cams can be reground to provide more lift and
more duration thus alowing the engine to breath better.
Get the head ported. A lot of HP can be realized by having an expert port
the head.
The first 4 are the cheapest.
Mike
----- Original Message -----
From: "Graeme Suckling" <graemes@saonline.com.au>
To: "Datsun Roadsters List (E-mail)" <datsun-roadsters@autox.team.net>
Sent: Sunday, October 20, 2002 6:45 AM
> Hi list,
> I'm getting close to sending a G1500 engine to the hospital for
> rejuvination.
> I have done a preliminary check on this that and the other, and I wish
> to know if the head (and performance) will benefit from a "head shave"
> to increase the compression ratio and therefore HP output. The engine
> had four siezed pistons due to a failed head gasket but there is
> minimal damage to the bores and to the water passages in the head. A
> truing cut will be required, but is a high compression head shave a
> good idea?
> A 1500cc engine in a 900+ Kg car may need some help!
> Induction will be stock twin SUs as with everything else, and I love
> the idea of cruising with just a bit more power!
> Thanks in advance.
> Regards,
> Graeme Suckling
> 1965 SP310 - under construction
> 1971 P510 4 door - daily driver, original owner
> 1972 P510 2 door - in storage
> 1973 HS30/240Z - re-building
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