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Re: Mounting the cylinder block

I've done both. Lowering the block onto the pistons is easier with two of you. No ring clamps here. Just fingers.

Re: Mounting the cylinder block

Like Alan and Ruairidh, I don't use oil baffles. Never have done but I imagine you could cut the corners and bend them out of the way as Alan describes if you really must.

Steve

Location: North Yorkshire

Re: Mounting the cylinder block

Appropo filing the rods, there is a tiny 'bump' on the rods near where the BE bolts go through. You only need to reduce the size of the bumps a bit to get the rod to go down the bore. No great engineering skill needed here.
I suppose with a highly tuned engine, more care would need to be taken - balance etc.

Location: Bonnie Galloway

Re: Mounting the cylinder block

I have always lowered the bock onto the crankcase, oil baffles in place. paper gasket in place on crankcase with sealant. A well greased and adjusted Jubilee clip around the top rings on nos 2 and 3. This method does require two pairs of hands. Lower block on displacing the Jubilee clips, reposition on the scraper ring and repeat. then Jubilee clip drops clear. Turn crank over to position 1 and 4 to slide in being careful not to displace 2 and 3. Fit Jubilee clips on 1 and 4 as before and lower. Repeat with scraper rings. Remove Jubilee clips. Paint on sealant to top of paper gasket and lower block to crankcase and tighten in place. Has never failed me. Always use brand new Jubilee clips. Can be done on bench or with crankcase in the chassis, but not bolted up and pulled as far forward as possible.

Re: Mounting the cylinder block

Yes, I know the theory, and I've even done it. All I can say is having built rather a lot of engines in my time, it's far easier the other way.

Re: Mounting the cylinder block

Lowering the block over pistons was more attractive with the original robust 5/32 rings. I recall a work colleague recounting how he and a mate labouriously fitted a block... to discover it was back to front!

The baffle questions very confusing. For racing the pumping losses are reduced without. With the alternate air rushing past how reliable are cut baffles long term?

For decades when in good order with original wide rings my car used almost no oil. But with modern rings even after a rebore the best I ever achieved was 1 pint per 300 miles of mostly 45-50 mph main road running, with baffles. So did not risk removing.

What consumption is achieved with/without? Has anyone done a comparison with no other change? I suppose the intention was to reduce oil consumption and not primarily to feed drained oil nearer to the con rod drilling?

Presumably the pressure fed engines omitted?

Location: Auckland, NZ

Re: Mounting the cylinder block

Alan, Im just very old fashioned, and see no reason to change a habit of a lifetime with Sevens. To be precise, a lifetime minus 15 years, equals 54 years.

Re: Mounting the cylinder block

I bow to your superior knowledge. That's a whole two years more than me. T

Re: Mounting the cylinder block

By no means superior knowledge. Im just a stick in the mud!

Re: Mounting the cylinder block

Funny how things recur, isn't it?
This thread prompted me to dig out my now fragile Design for Competition and to see that my father described all the above methods some 60 years ago.
As a point of interest, he didn't use baffles and inserted pistons and rods into the assembled crankcase and block.
If he had to use baffles, as for a customer, he preferred the lower-the-block-onto-piston method.

Location: Richmond, Texas

Re: Mounting the cylinder block

A few years old now but here is a short film I made to show the use of some cracking piston ring compressors I have, apologies if you have seen it before:

https://youtu.be/h3z-gQwRW5A

Re: Mounting the cylinder block

Hi Ruairidh

A delightful sequence.

Very, very many years ago I occasionally accompanied my infant son to the local play centre. The children were sometimes occupied in hammering activities and it was entertaining to ask each what they were doing. Many answers were imaginative, but not a single one replied that they were putting pistons into an Austin Seven!

Of all the Sevens in the world yours must routinely convey quite the most precious cargo.

Location: Auckland, NZ