Hello everybody,
I hope someone could help me.

At the moment I am in the process of rebuilding my 4AGE engine.
I want to replace bigport head with smallport head, what will happen with the TVIS activation on the ECU side?

When rebuild is done I will drive it for ~1000km till 3000 rpm, so I can be sure everything is ok. After 1000km I am will replace ECU with diypnp(megasquirt).

You can just leave the activation lead unpluged. The ECU functions by sending a signal to the vacuum canister, there is no any feed back to the ECU. Dave W

wewerica wrote:Hello everybody,
I hope someone could help me.

At the moment I am in the process of rebuilding my 4AGE engine.

Tell us more about the rebuild. Are you using stock parts, or some kind of aftermarket parts???

wewerica wrote:I want to replace bigport head with smallport head,

Why?

The most significant reason the smallport makes more power is it has higher compression. Raise the compression on your largeport, and you can make almost the same power. If you want to go meagesquirt in the future, there is a plug and play that works with the largeport.

@davew7 thanks for info

@oldeskewltoy
yes Im using smallport oversized pistons and NPR Europe piston rings, everything will be inside 3rib block.

for the head I will use smallport head with bigport camshafts (friend has the same setup).
basicly I wanted smallport head because air flow is better and I will get a bit more power then bigport.

I got 7AFE metal head gasket 0.4mm thin that should rise compression a bit

You will need to cut-n-shut the smallport intake manifold and delete the TVIS plate.
OR, use the bigport RWD intake manifold with a bigport-smallport adapter plate.

Cheers... jondee86

As mentioned the TVIS isn't a problem. Just leave it unplugged. Fueling won't be perfect but it will be pretty good.

Personally this is the break in I use and believe in.
http://www.mototuneusa.com/break_in_secrets.htm

I believe the thinnest 7A HG is .5mm. Even that is dangerously close and could cause the pistons to hit the head. If you have your block shaved it is very likely. With a .4mm headgasket I would nearly guarentee pistons would hit the head even with an unshaved block.

There isn't enough difference between the early and late cams to be worth the effort. In fact I have never seen anything that proved they made a measureable difference. If you really want to make your motor quick buy proper pistons and cams. Then you can smoke your friend

jondee86 wrote:You will need to cut-n-shut the smallport intake manifold and delete the TVIS plate.
OR, use the bigport RWD intake manifold with a bigport-smallport adapter plate.

Cheers... jondee86

I got smallport head with intake manifold.

yoshimitsuspeed wrote:As mentioned the TVIS isn't a problem. Just leave it unplugged. Fueling won't be perfect but it will be pretty good.

Personally this is the break in I use and believe in.
http://www.mototuneusa.com/break_in_secrets.htm

I believe the thinnest 7A HG is .5mm. Even that is dangerously close and could cause the pistons to hit the head. If you have your block shaved it is very likely. With a .4mm headgasket I would nearly guarentee pistons would hit the head even with an unshaved block.

There isn't enough difference between the early and late cams to be worth the effort. In fact I have never seen anything that proved they made a measureable difference. If you really want to make your motor quick buy proper pistons and cams. Then you can smoke your friend

Thanks for the info
A friend have sent me this page to read, but I was busy, now I have time and I will read all tnx

Two of my friends have .4mm gaskets on their 4AGE's, engines are running without issue. When I bought full gasket set I got standard head gasket if this isnt fitting I will put standard
After engine diypnp will come, already assembled and ready to put it in car.

I would like somene more experienced to take a look at ecu components.

wewerica wrote:
Two of my friends have .4mm gaskets on their 4AGE's, engines are running without issue.

Not sure about your friends.... Give this thread a view - viewtopic.php?f=13&t=16030

Guys engine is in the car and running.
Setup is the same as before.
bigport block
smallport pistons with smallport rods
smallport head with bigport cams
and 0.4-0.5mm head gasket for 7AFE

Which injectors are you using ?

At the moment I am in the at the beginning of breaking in my engine, running it till 3000 rpm for 1000km. after that I will instal megasquirt and 235cc injectors from smallport.

quick update on project.
Engine runs nice, better then the old one
I've tried to put DIYPNP in my car but got some issues that need to fix before.
I've loaded firmware into my DIYPNP loaded base map from website, calibrated all sensors, everything by the book.
When I start the car I got jumpy RPM's, car runs between 400rpm and 1500 rpm.

I have 4 tooth distributor like on the picture


Here are my settings