Lifter bores

[max Der Bahnstormerz]

Reaming the bores straight, found a few tight, high spots in them


Then radiused the bore face


Final job was to give each bore a quick polish


These guys should appreciate their new home, next on to crank clearance and valve timing

[andy198712]

looks nice! what lifters are they?

[max Der Bahnstormerz]

looks nice! what lifters are they?

Schubecks

[nicolas]

nice work. may i ask what machine you use to do this?

i used a very old at work to do this (horizontal mill, don't really know the name in english), most certainly 50 years old.

[max Der Bahnstormerz]

Just an adjustable hand reamer, a hand drill and a tool bought from Berg's 25 years ago to face the lifter bores.

Then finished off the bores with 120 grit loosely wrapped around a rod in a drill to hone the bores.

Nothing fancy, just lots of care taken not to remove too much material.

[Paul Bahnstormerz]

Heads done 😊


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[nicolas]

Just an adjustable hand reamer, a hand drill and a tool bought from Berg's 25 years ago to face the lifter bores.

Then finished off the bores with 120 grit loosely wrapped around a rod in a drill to hone the bores.

Nothing fancy, just lots of care taken not to remove too much material.

cool, but i assumed you fitted the bushes yourself as well. it looks really good.

[max Der Bahnstormerz]

Clearance checks all done, should be able to button up the bottom end tomorrow 

[Jesse/DVK]

Nice to see that you used the split bearing nr3

[Paul Bahnstormerz]

That doesn't look like the cam we were looking at over the weekend!


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[Jeff68]

Case assembly looks good.....What kind of crank is that?

[max Der Bahnstormerz]

That doesn't look like the cam we were looking at over the weekend!


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That one was too gay abou the same as a 125!! Going to save it for the SPG motor. I decided to use the 86c on 112LC and aiming for just under 10 to 1 CR. Need to keep up with you nitrous boys.

[max Der Bahnstormerz]

Case assembly looks good.....What kind of crank is that?

Thanks. That's an 84mm crank with a wedge mated flywheel from Bergs.

[max Der Bahnstormerz]

Oh no! Too much deck! Almost 100 thou without the copper head shim, need to get some thinner barrel spacers. Aiming for 10 to 20 thou plus a copper head gasket (0.040")

[Martin S.]

Aim for 40 th max. It will help reduce pre ignition.

[Paul Bahnstormerz]

Do you want my spare solenoids? 😉


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[max Der Bahnstormerz]

Aim for 40 th max. It will help reduce pre ignition.

is that 40thou in total? or 40 thou excluding the copper head shim?

[fish]

i would run .020 deck and .040 head gasket

[max Der Bahnstormerz]

i would run .020 deck and .040 head gasket

Cool, that's about what i was aiming for, possibly a little tighter to improve the squish.

[neil68]

My 2332 cc is similar: 0.020" DH + 0.040" copper head gaskets.

If you have piston notches, you could probably tighten up to 0.040" like my earlier combo, but would need high octane fuel.

[Martin S.]

I meant .040" total deck including copper gasket. If you need to lower compression dish the piston or do chamber work instead of adding deck. You want all the combustion to happen in the chamber and not in the outside edges where the pre ignition starts. My 1776 has 9.4:1 CR and doesn't ping on regular gas as a daily driver. The timing doesn't need to be advanced to make power either. Back the timing off and it still makes power 

[max Der Bahnstormerz]

I meant .040" total deck including copper gasket. If you need to lower compression dish the piston or do chamber work instead of adding deck. You want all the combustion to happen in the chamber and not in the outside edges where the pre ignition starts. My 1776 has 9.4:1 CR and doesn't ping on regular gas as a daily driver. The timing doesn't need to be advanced to make power either. Back the timing off and it still makes power 

Cool, that's the sort of deck I was aiming for, I've tried to keep as much of the squish area intact in the chamber and just unshrouded the valves as much as possible.

[Martin S.]

For comparison, here's a pic of how mine were ported. Yours have even more of a squish area intact.

[modnrod]

Can I please ask what heads they are?

[max Der Bahnstormerz]

they're CB comp eliminators

[Martin S.]

What cc are the chambers?

[max Der Bahnstormerz]

55cc's

[Martin S.]

So I get 10.4:1 CR, kinda high for pump gas but it might work. I think that's why my chambers are larger - he was trying to get the CR down for turbo. He also got 7cc's more out of dishing the pistons. The nice thing about the tight deck is that you don't have to run advanced timing to make power. Simply back off the timing until it doesn't ping and you're done.
https://www.cbperformance.com/v/enginecalc.html

[max Der Bahnstormerz]

I've always wanted to try to copy the combustion chamber shape onto the piston and then machine the piston a little to gain cc's, thus also keeping the squish area intact. Or maybe just pocket the area in front of the inlet valve, I think that would give the best results without lowering the CR too much.

[Martin S.]

You mean like this? If you had more like 60cc instead of 55cc your CR would drop to just under 10:1