blacktop 20v bottom end question

[hau oi]

wondering where can u get bottom end parts for blacktop 20v(pistons and bearing sets) ?
and do silvertop and blacktop share the same piston and bearing set?
cause ACL have them,but they say it suited for silvertop only, can anyone confirm.

cheers hau

[Matt]

The pistons are different.

A silvertop piston with a blacktop head will be a slightly lower CR ratio than stock, and vice versa a blacktop piston with silvertop head will be slightly higher comp ratio. They are interchangable as far as blocks go and can be interchanged as long as you don't mind an interferance engine if you use the blacktop pistons with a silvertop head and the different compression ratios.

If you are rebuilding, go for a silvertop oil pump and timing gear that way you won't have to mess around with the hydraulic tensioner etc.

Bearings are the same between the 16v and 20v all varients.

[Matt]

oh as for where to buy them, can still get new from toyota.

Also, the rods are interchangable... Allot of people bag out the blacktop rods for being light / weak, but i've never had a problem with them, at least not in NA form.

[Sam-Q]

the compression ratio change between the pistons is quite large.

[70XIN]

To add upon what Matt said: All of the 4A's use the same bearings, EXCEPT for early-model bigport and early GZE blocks. You are after 42mm rod bearings. Mains are all the same.

You can buy genuine pistons from toyota, or ebay (america). Not sure about aftermarket replacements.

[Delazy]

Ive got some mint 2nd hand ae111 pistons and rods ill gladly sell...

[Oly AE86]

I have new main bearings for sale, .025 Oversize in the ACL Race and 0.35 Oversize in the ACL Aluglide ->>>>

[Matt]

Sorry i was vague on what i meant...

The cr ratio between pistons is significantly different, but if you use a silvertop piston with a blacktop head, due to the combustion chamber size, expect the final CR ratio to be lower than the silvertop piston specs.

And if you use a blacktop piston with a silvertop head, you get an interference engine + higher CR ratio than the blacktop piston specs.