3 cc's was spot on using 0.030 and my deck clearance - thanks.
It is (or should become!) a race engine: I am rebuilding and upgrading on
the one I've raced for 1 1/2 season in Historics here in Denmark. The car
is/was also streetdriven, so wasn't too highly tuned. The block is an 1147
and the cylinder head is the Iron Stage 2 8-port head with a cam of
apparantly the same specifications as the original cam in the Stage 2 set.
With 2 Weber DCOE 40 and standard Mk3 valves it developed 79 hp at 6600
rpm.
During the rebuild I changed the cam to a Kent 264 reground item and have
cleaned up the cylinder head and am obviously hoping for a bit more power,
while still being able to drive on the street occasionally - at least to
and from the races, as I've done so far. I would also like the engine to
last more than one season...
Yes yes, a bit compromised, but I am realizing that I prefer driving over
long days in the garage. Next step is better flowing valves and radiused
seats, but that will not be until next year. I have 2 spare 1147 blocks so
might be able to reduce compression ratio by using a block with more deck
clearance. My own quickfix thought up solution for reducing the
compression ratio was 2 using head gaskets, but I am told that's a bad
idea. As far as my calculations go that would take the ratio back to
around 1:11,4 as Michael Porter suggested to aim for.
That might be a more practical solution than trekking to Germany for some
of that Shell V-Power 100 octane pump fuel...
Use 3 cc's for the volume. That will be very close. What are you
> trying to accomplish - race, hot street or ???. Please let me know if
> we cnhelp. Ted
>
> claus@triumphracing.net wrote:
>
>>I'm trying to calculate the compression ratio on my Spitfire 4 with the
>>Stage 2 cylinder head. I have the chamber volume and deck clearance as
>>well as the given dimensions from the bore and stroke, but can't find a
>>measure of the head gasket thickness when compressed. I use a standard
>>4/Mk2 head gasket and standard torque settings. Does anyone have a figure
>>for this?
>>
>>Regards,
>>Claus Ebberfeld
>>
>>
>>
>
> --
> Ted Schumacher
> tedtsimx@bright.net
> http://www.tsimportedautomotive.com
> 108 S. Jefferson St.
> Pandora, Ohio, USA 45877
> Fax: 419.384.3272 (24 Hrs.)
> Phone: 800.543.6648 (US & Canada)
> Tech/ Gen. Information/ Worldwide: 419.384.3022
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