datsunmike wrote:
>
> Has anyone purchased a big valve 1600 head from Dean at Fairlady? I was
> thinking of doing so for my stroker project and was just wondering.
Let me say right up front that I do not know Dean nor anything about these
heads. What I am about to say is based on my experience in racing and the
automotive business over the past 20 years but not on any info I have specific
to Dean or anyone else.
I would not recommend buying an over the counter modified head from anyone who
didn't build it themselves. I also would recommend against buying any
"performance" parts that were modified in a vacuum, that is without concern for
the other engine components they will be used with.
All engines are systems, where each individual component must be designed to
work with all the others. While I realize there is a great body of data out
there about modifying Roadster engines, I still do not believe that anyone can
build a modified head that will work with all engines or that there is any
successful "universal" head formula. I have seen modified heads on various
engines that cost power in one engine and made power in another. Sometimes just
changing the cam would make the head work well, other times the modified head
just never could be made to work as well as a stock head. Head modification
takes a lot more science than most engine hop-up shops or parts places are
equipped for, and often power is lost by simple things that seem irrelevant,
such as valve seat height. For example, in an L24 (Z car) head, you can lose as
much as 10 hp or more simply by raising or lowering the location of the valve
seats by as little as 0.125"
If you want a performance engine, source your parts from someone who can supply
all the parts you need as a package, based on their experience in building and
supporting similar engines. It will cost more up front (perhaps a lot more) but
it will save you money in the long run and ensure that you don't waste money on
useless junk.
One last thing, even some famous engine builders and parts suppliers are not all
that good at this sort of stuff sometimes. That's why you hear about things like
Jaremko blowing his Rebello motor in its first or second race. But at least with
businesses like them you know they deal with race motors all the time and
understand, at least to one degree or another, how engine components are all
interdependent. If the person selling the part is not an engine builder, has no
technical or engineering background in the field of high performance Datsun
engines, and has no racing technical experience, he is obviously selling
something he knows little or nothing about. If that is the case with Dean or any
other vendor, then I would not buy a modified performance engine part of any
sort from them. OTOH if they do have a background and experience that let's them
understand the ramifications of the modifications made, then by all means source
your parts from them. As I say I know nothing about Dean or his background.
While not meant to be disrespectful of Dean or any specific company, nor to
assert any incompetence on anyone's part, I am concerned my comments might be
misconstrued by some, and I do not wish that. So I am reasserting again that my
comments are NOT based on any experience, opinions, or specific knowledge I have
regarding Dean or any specific company. My comments were directed towards the
larger issue of buying over-the-counter performance parts and "generic" modified
parts, and not about any specific person or business. ;-)
--
Marc Sayer
82 280ZXT
71 FJ510
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