5a-ge 20valve

[DeftAnesthetik]

Just curious if anyone has dropped a 5A crank into a 20v or has heard about it being done. And if so what kinda results.

[adamaw11]

People have done it with the 7A to get a1.8L 20v but due to the longer stroke there are issues with it not revving as high

what capacity is a 5A?

[oldcorollas]

5A looks to be 1.5L

same stroke of 77mm, but smaller bore of 78.7 vs 81

same crank?

adam, don't they use the 7A block?
is it possible to fit a 7A crank in a 4A block and still have long enough rods?

[Starfire]

Is this for some sort of racing class?

You would probably be better off getting a 20v bottom end and modifying the bore/stroke by sleeving and offset grinding to get the displacement that you want. That way you can get the absolute best casting that toyota made in the series combined with optimized bore and stroke for your application.

If you are looking to do it on a ghetto type budget it would probably work just throwing the head on but I doubt that the results would be spectacular. Timing belts could be an issue.

[kingmick]

Is this for some sort of racing class?

You would probably be better off getting a 20v bottom end and modifying the bore/stroke by sleeving and offset grinding to get the displacement that you want. That way you can get the absolute best casting that toyota made in the series combined with optimized bore and stroke for your application.

If you are looking to do it on a ghetto type budget it would probably work just throwing the head on but I doubt that the results would be spectacular. Timing belts could be an issue.

im really confussed on this!
why would anyone use a 5a over a 4ag setup. if i was racing in unders i wouldnt use a 20v in the unders{2litre} as you wouldnt even come close to getting the HP needed to be close to the pointy end. a custom 7a is about them minum now as you set them up for over 1.9litre with custom rod and piston etc. these give you between 180-220hp{you could get more but the rev limiy in class is 7500} at the wheels depending on the setup!

i cant even think of a good reason to use a 5a for anything.

[takai]

In the US and Europe there are quite a lot of <1.5L and <1.3L classes. That is why you would run them.

[kingmick]

i ment 7age aswell as the 7a with the 20v works out a bit less HP and cost more to do properly and was way more mucking around.
1.5 litre class id use a 20v and take it down a fraction.

[adamaw11]

5A looks to be 1.5L

same stroke of 77mm, but smaller bore of 78.7 vs 81

same crank?

adam, don't they use the 7A block?
is it possible to fit a 7A crank in a 4A block and still have long enough rods?

yeah the 7a block is actually taller
So I'd guess may not be possible to use the 4a block, but I don't know.

Ray hall turbocharging used the 7a block, and 7a crank, aftermarket rods
http://www.turbofast.com.au/mr2.html


and its sounding pointless to use a 5a for anything, as people mentioned.

what sparked the question DeftAnesthetik?

[oldcorollas]

i imagine he was thinking of the stroker kit (HKS?) that was commonly known as the 5AG kit.... as it made the 4A bigger capacity... but it just so happens the 5A is smaller (like the 2K and the K )

as for 5AG stroker kit, there was a set of pistons for it (apparently) on yahoo recently, but no crank.

[myne]

I wouldnt imagine it'd work terribly well without extensive re-work of the head.
Mainly you'd have to check valve-to-cylinder-wall clearances, probably weld in some extra material to match the bore (unless you want a mushroom shaped combustion chamber).

Assuming this was for a particular race class (1500cc), I still cant think of any reason to do it. You'd be far better off de-stroking the 4A to something like 68mm which by my calculations gives 1471cc.
Then you keep the breathing of the head intact, up the revlimit significantly and you only need new conrods if you're happy to weld the crank.
It *might* come into the range where some relatively small big-end motorbike rods will fit which might eliminate the need to weld the crank.
Biggest problem is, you're going to lose a bit of compression. Again, there might be some suitable motorbike pistons.
Up side, you've got the excellent breathing of the 20v with an insane revving bottom end. I wouldnt be surprised to hear 12k reliably. The valvetrain might be a different story.

[oldcorollas]

or you could just put the 4AG head on the 5A block for 1500cc (stock destroked 4A ) you would be getting light pistons and better rods for any serious application anyway.

[ViPeR_NiPPleX]

I was pretty sure the 3A was 1.5L... ? and the 5A was merely what a stroked 4a hks kit was considered.

[oldcorollas]

google for 5AF and 5AFE

[myne]

or you could just put the 4AG head on the 5A block for 1500cc (stock destroked 4A ) you would be getting light pistons and better rods for any serious application anyway.

Um no.
http://www.toysport.com/Technical%20...spec_sheet.htm

[ViPeR_NiPPleX]

what the hoo haw? 3A and 5A are both 1.5l ?