>On the head front, I seem to be fortunate since the later 72 '6s had the PI
>type head (for some strange reason, the US-spec cars from 69-mid 72 had
>different port spacing) - the clue to having the "correct" PI type head
>being the double downpipe exhaust header. This head also often came with
>double springs (but not always on the later years), but that is an easy fix
>anyway.
The PI head is much thinner than the carb head to give 9.5:1 compression.
You can simply shave your carb head to get the compression ration where
you want it. Mine was at 10:1 but after installing .030 over pistons
>and machining another .007 off the head (slight warp at last rebuild) it is
now somewhere around 10.3:1. Runs fine on 93 octane.
>I have got some rebuilt injectors from TR Traders in the UK (reasonably
>priced too). The metering unit was said to be in good condition, so I'm
>going to leave that alone until after it is running. On that front, I have
>traded emails with a lot of folks about retrofitting PI systems, and all
>those who have had an metering unit and injector rebuild have had a load of
>problems ... this may just a coincidence, or it may be a factor of too many
>things at one time, so I'm going the slowly-slowly route at this point.
I bought a set of rebuilt injectors from Rimmer last year (mine had about
50K miles on them and were dribbling and uneven) and have had no
injector problems since. The control section of my original metering
unit wore to the point where the control arm was flapping around so I
swapped it for a spare (new-old-stock) unit I had, but I've done nothing
with the metering pump itself and it runs just fine after many years
of unleaded fuel.
One problem I would like to solve is overrun- if I leave the car in gear
and take my foot off the gas while going down a hill I get overrun
popping. Is this normal? Will a vacuum advance or recalibrated
metering unit solve this problem?
-Erik
--
Erik Quackenbush, V.P. Operations, Midwest Filter Corporation
1-847-680-0566 fax: 1-847-680-0832 http://www.midwestfilter.com
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