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Bad Bob wrote: ↑Mon Jun 08, 2020 9:29 pm You better find out for sure what the volume of your chambers are. It’s easy to do with a syringe and a plate of lexan or acrylic. If you have a step cut in your chamber, that counts as part of the .040 clearance you need. Measure the height of the step and the chamber volume and you will know for sure what your C/R is. No short cuts here!

Sorry, I can see what I wrote wasn't exactly clear. Yes, I measured it with a syringe. The chamber measures 55cc but there's also a step cut which I counted as being part of the chamber, not part of the deck height clearance. This took another 10cc to fill.
I'll measure the depth of the step today instead and see what my deck height is if I add it to the piston to barrel top measurement. Here's a pic of the head chamber. Cheers

Ok. I've realised it shouldn't matter if I measure the step as part of the head cc or the height and work out the cc from that...doh!
So, with a 55cc chamber volume, 10cc step volume, and 2cc deck volume (pi x 4.4cm x 4.4cm x 0.033cm), I get:
Total volume - 67cc + 450 (cc of one cylinder) / 67 = 7.716:1, which is the same result I get when using the CB calculator.

So my initial concern was that I didn't have enough deck height from piston to top of barrel but due to the step in the cylinder, this is making up for it.

So, then my thought was should I ditch the 60 thou barrel shims and just use the 40 thou copper head shims? But then the piston will be protruding from the barrel at TDC by roughly 47 thou which I don't think would work too well...

Anyway, I think 7.7:1 should be ok with the supercharger.

Looks like you have it under control. I’ve always used a minimum of.040-050 clearance above the piston. You could use the copper gaskets with thinner barrel spacers. Just as a warning, I used some no name copper gaskets in my turbo motor and they crushed down unevenly. I bought some from CB as replacements but haven’t run it yet. It has 7.5:1 comp. ratio and worked well with 91 octane in my daily driver.

Thanks, I bought these copper shims from CB. I'll keep the post informed as I make progress.

It's coming along nicely. Temporarily fitted the heads so I can check the rocker fitment and push rod length I'll need.

For anyone following or mildly interested, I've got the motor all together.
I had to leave off the scat pro street 1.25 rockers for now as I don't have the correct length pushrods.



The pict34 will do while I run it in.
I'll be fitting it tomorrow.

Far out! How exciting great luck on the run in:)

Well, I had trouble with pict34 getting it to idle. I don't think it's big enough for the motor. Understandable, as the intake manifold runners are very small. So I swapped it for some twin 40 dellorto's that I had to rebuild first. I also had to change to the aftermarket fan shroud as the original one was too wide for the dellorto's.
I've only taken it for a short drive as I haven't got a timing light or carb balancers with me.
But the straight cut gears sound great and it does go a LOT better than before already!



I'm finding out all sorts of things with this car. I thought I'd fit a new shifter bush. I bought 3 of them because I'd read that they wear quickly. Well my car didn't have one at all! Further reading I discovered the '59 doesn't have one, it's just metal on metal in there.
My new cheap sand seal pulley is warped, and the belt doesn't line up with the alternator any longer.
I've also fitted a camber compensator in the rear.
And I can see I have one small leak from the case halves right near the sump plate

I like it, it’s a nice looking Baja

Hey, Rick,

Any updates?

I may have missed it but do you have a Truss/Kaffer bar yet.

Lee

Shane Tuttle wrote: ↑Mon Oct 19, 2020 6:04 pm Hey, Rick,

Any updates?

Sorry, I've been away for a while.
I have the supercharger fitted and it goes really well. I'm just using the 34pict 3 modified with a bored out venturi and bigger main jet. Unfortunately, I've got issues with pre-ignition once the engine heats up. Seems fine on the highway but at low speeds after a while, it starts to ping. I'm only driving the car very occasionally so not to risk damaging it until I can figure it out.
I haven't got any gauges fitted yet so I don't know the oil or head temperatures and the ambient air is hot here ~35°C.
I'm going to fit a remote oil cooler.
I've fitted the 36-1 trigger wheel and sensor ready to fit programmable ignition and then sequential EFI.

Can anyone recommend a cam size for a 1915cc I was told that the Fk-8, eagle 110 and the eagle 120 were to large for the compression ratio I'm shooting for wich is 8:5.