Lots of times lift is measured at the valve. Your
rocker arm will apply leverage at a larger ratio. The
lifter may only move .235" but the valve moves .335".
If you decide on the port and polish I would suggest
taking it to someone that specializes in that head. You
definately don't want a hillbilly dirt-track motor
builder trying to grind your head like he did his
cousin's brother-in-law's small block Chevy last week.
A good three angle valve job will make a big improvement
on it's own.
Andy
> Mike, P&P means Port and Pollish, right. I have heard of this (Home
> Improvement TV show) but don't exactly know what it is. I have a small
> machine shop in my garage and am fairly handy with tools. Is this something
> I could do myself? I believe it means to round off the corners of the
> intake "holes" in the head. I could do this on my mill with a "quarter
> round" end mill, or do you do this by hand with a grinder? Might be fun to
> do if it will help the engine perform better.
>
> My engine ('70 1600) is apart. Cylinders seem to be just barely out of spec
> for the standard size, so expect to go to the first oversize. This means
> new pistons, right? The amazing thing to me, considering that most of the
> things I have measured are not that worn, is that the cam seems to be REALLY
> WORN. It is supposed to have a lift of 0.335" or so (which I assume means
> the lobe-to-bottom distance minus the diameter of the non-lobe portion of
> the cam). I measure this to be about 0.235 which is 0.1" smaller!!! Yet the
> cam looks good visually. This is my first engine job and so am not
> experienced at this. This engine is the original in my '70 1600 and has
> about 180K miles on it.
>
> Boy, I got carried away with this. Sorry it is so long. ...guess since
> this is my "first time" I'm nervous about being sure to do everything right.
>
> Thanks for your response and that of the 4 others who responded to my
> question.
>
> Bob Wilson
>
> -----Original Message-----
> From: datsunmike [mailto:datsunmike@nyc.rr.com]
> Sent: Tuesday, August 15, 2000 4:08 PM
> To: bob_wilson@agilent.com
> Subject: Re: Engine Shop in San Jose?
>
>
> Bob,
>
> Get some head work done too. You know P&P and a nice 3 angle valve job. As a
> racing engine builder told my club the power is in the head!
>
> Mike
>
> ----- Original Message -----
> From: <bob_wilson@agilent.com>
> To: <datsun-roadsters@autox.team.net>
> Sent: Tuesday, August 15, 2000 10:32 AM
> Subject: Engine Shop in San Jose?
>
>
> > Can anyone recommend a good shop in the San Jose area where I can have my
> > engine work done? I have it all apart and need the crankshaft turned,
> > cylinders bored (I think), valves ground, ... 1970 1600 spl311-28383
> >
> > Bob Wilson
> >
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