Expanding Pistons

[Bender Unit]

Bore and piston sized are linked end of. Who fits a small piston into a big bore?!

[ENSMR2]

I'm no expert but wouldn't the displacement be relative to bore size rather than piston size?

i.e. The volume of air in the cylinder according to the length of stroke multiplied by four?

Yes, larger then stock pistons mean larger bore which then increases displacement.

The displacement is obtained from Toda I didnt work it out.

It would have been 2161cc if I had 86mm pistons.

[ENSMR2]

FYI the circle with the line through (phi) is the standard symbol for diameter.

Also - we need to get the block rebored on our SC, but the machine shop won't do it until we have the pistons so they can measure them individually and then bore to fit.
If you're putting new pistons in, it might be worth taking the block and pistons somewhere for precision measurement - if nothing else, you can match up the cylinders with the best matching pistons.?

The thing is anna, different pistons expand by differing amounts.

So you really need the spec sheet, which I don't currently have

[aaronjb]

I hope you or your builder will be measuring them properly (with a set of verniers) before touching your block

Obviously.

Just checking Horrible visions of you with a plastic ruler and a honing tool...

Bore and piston sized are linked end of. Who fits a small piston into a big bore?!

Me.. every time I sleep with someone..

I mean.. uh.. oh.. engines.. yes..

[FreeFall]

Bore and piston sized are linked end of. Who fits a small piston into a big bore?!

LOL - no-one I would hope!

Yeah I realise that mate. I wasn't having a go as I also realise that you have probably forgotten more than I'll ever know about rebuilding engines. I was merely pointing out that if you are doing a displacement calculation, you should measure the bore size and not the piston size. If you're measuring the piston size then shouldn't you measure out to the edge of the rings?

I'll say again - I'm definitely no expert (i.e a noob) at this sort of game, I.T. is my game and I just pay someone else to do the work on my cars but I'm always up for learning new stuff. So if I'm still wrong then please let me know - I'll never learn otherwise

[Bender Unit]

Just checking Horrible visions of you with a plastic ruler and a honing tool...

Or the super accurate use your fingers as a ruler technique which will make everything seem the same size until you try and fit it all together.

Me.. every time I sleep with someone..

Its not all about the size of the bore, its also the length of your stroke.

[ENSMR2]

I hope you or your builder will be measuring them properly (with a set of verniers) before touching your block

Obviously.

Just checking Horrible visions of you with a plastic ruler and a honing tool...

Bore and piston sized are linked end of. Who fits a small piston into a big bore?!

Me.. every time I sleep with someone..

I mean.. uh.. oh.. engines.. yes..

LOL

I have some vernier calipers on their way to me at the moment so I can measure them properly lol

however

they will masure less then 87 cos they will expand
thats why I need the spec sheet.

[^Trickster^]

In reality, the piston size is irrelevant.

Its the skirt to bore clearance that is essential in correct ring size and prevention of severe slapping pistons.

The machine shop should take your pistons, measure the correct diameter at the skirt, and bore the block to accomodate the clearance neccesary by the piston manufacturer.

Its not something i tend to worry too much about, the amount of displacement gained by this is negligable really, just get that engine built

Graeme

[ENSMR2]

In reality, the piston size is irrelevant.

Its the skirt to bore clearance that is essential in correct ring size and prevention of severe slapping pistons.

The machine shop should take your pistons, measure the correct diameter at the skirt, and bore the block to accomodate the clearance neccesary by the piston manufacturer.

Its not something i tend to worry too much about, the amount of displacement gained by this is negligable really, just get that engine built

Graeme

I would love to but no job is a rather large drawback ATM.

Plus I don't know what the manufacturers clearence figures are as they came with no spec sheet. This is being chased up though.

[FreeFall]

I have some vernier calipers on their way to me at the moment so I can measure them properly lol

Sent first class this morning - no rush to return them mate

[ENSMR2]

I have some vernier calipers on their way to me at the moment so I can measure them properly lol

Sent first class this morning - no rush to return them mate

Top man!

Owe you one bud!

[MegatronUK]

Where's the rest of the extra capacity coming from, you got a different crankshaft?