1620 questions/ potential build thread

[rollinmunkey]

Alright, I'm going to start my own thread here, possibly turn it into a build thread in time, but I'm kinda trying to feel this out some first. Have a few questions because I'm not sure specific dimensions, compression, etc of the 4age 20v or 16v.. So here are a few.

1) Is it better to use a s/t or b/t bottom as a base? And why?

2) What dimension headgasket would I need to run to prevent issues?

3) Is a higher volume fuel pump needed?

4). Can I run the 20v itb's or carbs? What's better?

5). What cam dimensions/profile would I have to run?

6). Heard about using supra 7mge injectors with a wideband and fuel pressure regulator with 16v ecu? Is it a safe setup and what pressure to regulate fuel?


So this was supposed to be saved as a draft so I could do a bit more research before posting, but idk what went wrong there

[dr.occa]

Alright, I'm going to start my own thread here, possibly turn it into a build thread in time, but I'm kinda trying to feel this out some first. Have a few questions because I'm not sure specific dimensions, compression, etc of the 4age 20v or 16v.. So here are a few.

1) Is it better to use a s/t or b/t bottom as a base? And why?

differences to note which may help you decide for yourself:
ST-beefier bottom end shared with hi-comp small port and gze
BT-lighter botom end same crank 42mm wrist pin as hi-comp, GZE & ST but better balanced and more responsive

2) What dimension headgasket would I need to run to prevent issues?
Close to factory 16V compressed thickness from Cometic

3) Is a higher volume fuel pump needed?
Not necessary. Same as Supra. McKenney pointed this out in one of his threads IIRC.

4). Can I run the 20v itb's or carbs? What's better?
Both are probably equal in cost but:
the EFI option requires either a stand alone or blacktop harness and ecu conversion.
the carb you'll need to run a bypass type fpr, 3/8 lines to and from tank, jets & custom ignition

5). What cam dimensions/profile would I have to run?
With 16V head you can run stock. It's all up to you.

6). Heard about using supra 7mge injectors with a wideband and fuel pressure regulator with 16v ecu? Is it a safe setup and what pressure to regulate fuel?
The ideal method is for stand alone and the proper injectors to tune out the lean condition that's been commonly observed with both 16V & 20V factory tunes. My 2 cents. Spend it now and save money or spend more later and get a free upgrade in frustration.


So this was supposed to be saved as a draft so I could do a bit more research before posting, but idk what went wrong there

[rollinmunkey]

Okay.. So if I go with a b/t bottom end and decide on itb's, and factory 16v cams, i would need a standalone and larger injectors.. What brands have you used and what size injectors would you recommend. Also, I was reading some of the other 1620 threads and read something about being limited to race fuel, would that be the case with the above mentioned setup?

Sorry for the headache, just trying to make sure I understand what I'm getting into before swimming with sharks.. Lol

[dr.occa]

You're not limited to race fuel. The compression doesn't come close to making that a necessity.

For stand alone I suggest investing in a unit that makes it easy when wiring everything up and is widely worked with and familiar to any performance shop in every state you might possibly live in or move to. e.g. haltech, aem, motec, greddy e-manage, etc...

If you want to go more diy then at least go plug and play megasquirt from diyautotune.