How close is Too Close? Vvega,Redmist,Fivebob?

[ee904age]

Hey,

Ive just put the silvertop pistons and rods into my bigport redtop, and Huston, we have a problem.

The bigends havent been torqued up but.... when I sit the head on without a gasket and turn the crank, the pistons are tapping the head

This doesnt happen with the gasket on (stock gasket), but the head is also not bolted on.

What I was thinking is, with the head torqued up and the gasket compressed this may cause a problem.

I will definately be putting plasticine (sp?) on the pistons and doing a test before running it, but if it turns out the wont hit, is it still too close to be safe??

EDIT: I havent got to the compression ratio yet, one hurdle at a time is one too many!!!!

[Lloyd]

May seem like a silly question, but with the head just sitting there do you have the cambelt on? May seem obvious, but just checking

[Akane]

the gasket don't compress that much you know.......... so yes, that'll be your problem. Unless you use non standard rods and pistons and crank.

And you can always take the pistons out from below.... that's how I took my JE's out on my 3S-GTE.

edit: just read your post properly, so is that silvertop pistons into a silvertop block but a 16v head? Silvertop will have 5 grooves on the pistons to accomondate the 5 valves. I don't see how this will work. You gotta ask vvega he's into those smaller 4A-GE's

[ee904age]

May seem like a silly question, but with the head just sitting there do you have the cambelt on? May seem obvious, but just checking

Nope, the head is bare. Havent got my verniers here but if whatever the thickness the gasket is, is all the clearance I have, will it be ok?

The valves may become an issue aswell but I'll get to that once the head is together.(it will obviously become an interference engine)

[Mr Revhead]

fyi the 16v gasket thickness when torqued to spec is 1.2mm.

id suspect that using 20v pistons with a 16v head would just make it an interference engine, but i dont know for sure, the usual combo iv come across is 20v head on 4agze pistons.....

try looking at a good engie building site/book, a lot will tell you how much static clerance you will need

[GOLDAE86]

Ive done it to several cars down here and have had no problems.I suggest u place a layer of play dough on top of the piston(about 3mm thick or so), place an old head gasket and cylinder head on the block torque it down, put some cams in it, turn one cam shaft at a time a full turn, then remove the cylinder head and remove the dough carefully and meausure the clearance between the piston face to head, and valve clearance to piston.By memory i had about 1.5-2mm clearance everywhere.

[NZ_AE86]

Have done this a couple of times and it works just fine, if you break a cambelt you will bend valves but will run just fine!