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1620?

Posted: Thu Aug 13, 2009 1:14 pm
by CBR_TOY
i'm considering this as an option.... what would make it a better option than just a plain old 20v swap?

the hp numbers are starting to concern me with stock bt's

Posted: Thu Aug 13, 2009 2:10 pm
by ga_goosh
what i want to do is get a BT bottom end and a small port head with ST itbs and megasquirt. but that is just me. if you leave the BT pistons and use the small port head your static compression will be around 11.4:1 if you use the silver top pistons your static compression will be around 10.1:1. but you will have an interference motor on both 20v pistons. you can changer the dynamic compression on cam choices to use the BT pistons and have a nice revable motor.

Posted: Thu Aug 13, 2009 2:23 pm
by CBR_TOY
that's what i was thinking of doing with my bt.....

small port head on bt bottom end with some stand-a-lone (ms maybe) and running my bt itb's

i don't know which setup would have more potential though

i think the 1620 considering the 16 head and easier accessible cams and other goodies

Posted: Thu Aug 13, 2009 2:41 pm
by ga_goosh
that is my main reason it is a PITA to get BT stuff. plus the wiring is alot easier

Posted: Thu Aug 13, 2009 2:45 pm
by CBR_TOY
true true... i'm still debating on it right now. the bt block has 81.5mm stock toyota pistons and a .8 heaad gasket.....

this is tougher than i thought

Posted: Thu Aug 13, 2009 4:52 pm
by dr.occa
16v affords better low trq and again, another repetitive reminder on cam profile availability.

just keep in mind it does become an interference engine but so are hondas and a lot of us here should have had some experience with them as well...or no?

Posted: Thu Aug 13, 2009 6:22 pm
by ga_goosh
CBR_TOY wrote:true true... i'm still debating on it right now. the bt block has 81.5mm stock toyota pistons and a .8 heaad gasket.....

this is tougher than i thought
well the 81.5mm pistons are going to bump up static compression to about 11.5:1. if you do go this route, i would use a oem 16v head gasket other wise your SCR will be over 12:1 and you will need some crazy cams to make that work

Posted: Fri Aug 14, 2009 7:53 am
by CBR_TOY
wow ok.... well i'll have to think about this now

not sure what i wanna do. all i knoow is that i'm tired of the slow stock paper weight

Posted: Fri Aug 14, 2009 10:34 am
by CBR_TOY
saw your post on club4ag jonas... think i'll just stick the damn 20v in how it sits



thanks guys

Posted: Fri Aug 14, 2009 3:46 pm
by ga_goosh
with the BT bottom and the small port head and a static CR at 11.5:1 you can get a cam where the intake valve closes at around 65 deg then your dynamic compression would be about 9.15:1. which would need premium pump gas. a cam at this spec is really close to what the oem 20v ae111 cam is at. it would be a nice performance motor and would rev probably to about 9000 fairly easy and would make power that high depending on what duration you run. and of corse fuel management

Posted: Sat Aug 15, 2009 11:54 am
by dr.occa
the attraction is:

1. the availability of cams, springs, valves.

2. the automatic bump in compression.

3. and the use of oem thickness head gasket while maintaining the compression increase.

4. the better low throttle response the 16v has over the 20v.

5. better bottom end internals.

even better would be running the tri-flow colt cams with a 1620 which has been shown to net gains in trq throughout the rpm range: from start to end.

just re-iterating, the magic in the 4AGE for producing power (pretty much for almost any engine for that matter) will be higher compression, cams and port work. with the 1620 you easily get all the benefits mentioned.

Posted: Sat Aug 15, 2009 7:57 pm
by CBR_TOY
what about the bt pistons? would they work well with a 16 head?

can you just bolt a smallport head on a bt bottom end and stick a ms on it and that'll work?

Posted: Mon Aug 17, 2009 2:17 pm
by ga_goosh
CBR_TOY wrote:what about the bt pistons? would they work well with a 16 head?

can you just bolt a smallport head on a bt bottom end and stick a ms on it and that'll work?
the BT pistons will work you just have to have the right cam to keep your dynamic compression under control other wise you will be limmited to race fuel only you can set up your engine to run on e85 with the high compression.

Posted: Mon Aug 17, 2009 2:17 pm
by CBR_TOY
ok.... if i bolt a small port head (incl. NST Tri-Flow Cams/Gears) to my bt 20v bottom end with MS whatever.....

will it work?

Posted: Mon Aug 17, 2009 2:20 pm
by ga_goosh
it depends on the cams do you know any specs on them? spacificaly what deg the intake valve closes (abdc)