Your opinions please

[M-j-b]

So.....
L28 engine with an N42 block and N42 head.
It's basically the very first iteration with smog kit. EGR, Charcoal, Cat. All this is going.

Plan:
Lightened billet flywheel

Jenvey intake (independant 6 x TB upgrade) with injectors

Fast EFI upgrade

Zstory race sport header, line and JDM box

My questions are, should I?

1: upgrade injector CC ?
2: change dish pistons for flat tops?
3: anything different from above?

My theory on injectors is, I will be breathing and farting so much easier. Therefore I am at risk of leaning out (had an evo that did the same) new EFI should adjust if a little rich !?!

Flat tops.... is it worthwhile opening up the engine to do only this mod? I'm not up on engine internals.

Your opinions please. Thanks

 

[Alphabettispaghetti]

fur coat and no knickers?

you need flat tops and a cam. all the above mods should be done after some internal stuff.

 

[johnymd]

You will see zero performance increase (and maybe a drop) with the above mods without increase in compression and a cam, as Franky said. Trouble is it then escalates and you spend much more than you thought. This is exactly what happened with the engine in my silver car. Started with an n42/n42 l28. Went FI then realised this engine is actually really low on power. So I started with a cam, followers. spring ect, ect. Had a very good modified head already. Engine could do with a refresh and come by a ld28 crank so went forged rods and piston, which were all relatively cheap. Add all the other parts required for any rebuild and you've suddenly spent the best part of £8K. Its hard to do a cheap performance l-series as the costs just seam to add up quickly.

My advice is either keep engine as is and fit SU's and electronic dizzy or go for a £4-8k engine build with FI. You could do a flattop l28 with cam and all the usual rebuild parts for under £4k.

 

[status]

Do wot I did
Get a 3.2 Rebello for about 8 k ish and you have instant power,simple really

 

[Mark N]

Do wot I did
Get a 3.2 Rebello for about 8 k ish and you have instant power,simple really

What spec of engine do you get for 8 grand?

 

[jonbills]

http://www.rebelloracing.com/enginebuild.htm

 

[Mark N]

http://www.rebelloracing.com/enginebuild.htm

I read it before but it doesn't give a great deal of detail, especially regarding any head work.

"This engine is sold ONLY as a complete assembly. Base price includes, Block, Forged pistons, Billet connecting rods, and rod and main bearings. Customer supplies cylinder head core, does not include Diesel crankshaft.

Engine long blocks starting at $8900"

Do you pay extra for the crank?

 

[M-j-b]

You will see zero performance increase (and maybe a drop) with the above mods without increase in compression and a cam, as Franky said. Trouble is it then escalates and you spend much more than you thought. This is exactly what happened with the engine in my silver car. Started with an n42/n42 l28. Went FI then realised this engine is actually really low on power. So I started with a cam, followers. spring ect, ect. Had a very good modified head already. Engine could do with a refresh and come by a ld28 crank so went forged rods and piston, which were all relatively cheap. Add all the other parts required for any rebuild and you've suddenly spent the best part of £8K. Its hard to do a cheap performance l-series as the costs just seam to add up quickly.

My advice is either keep engine as is and fit SU's and electronic dizzy or go for a £4-8k engine build with FI. You could do a flattop l28 with cam and all the usual rebuild parts for under £4k.

Thanks for the response, I understand that feeling of it leading to a never ending bill.

The trouble is for me, there isnt an infinite budget, which appears most people with Z's must have..
I have completely nut and bolt restored the car, and away for a re-spray. While its away I am prepping the engine.
Changing sump gasket and water pump etc etc...

I couldnt warrant spending 8k.

I have no choice but to change the EFI as my ECU is not functioning correctly.

I also am removing smog etc. So changing the exhaust and manifold (cat removal).

I'm really surprised that doing all this would reduce power...

So without spending 8k or even 4k...
What are my options?
Complete waste of time changing to flat tops?
Even if I aim to do a cam change down the line.

As I may need a financial recovery period...

I need to become Pablo Escobar to own a Z... I thought Evo's were expensive to mod

 

[zbloke]

I have no choice but to change the EFI as my ECU is not functioning correctly.

What's wrong with your current ECU?

Could you get a modern ECU, Megasquirt for example, and use it to run the OEM injection system?

 

[M-j-b]

What's wrong with your current ECU?

Could you get a modern ECU, Megasquirt for example, and use it to run the OEM injection system?

Whilst it tests as firing the injectors, there isnt enough amperage to fire (swap polarity)

I have opted for EZ EFI.

As for the OEM system, issues I have with it.
EGR removal
Poor/lack of fuel rail
Degraded pipework
Removal of AFM
Addition of new sensors into OEM system
New injector plugs required
Tidying the engine bay
Small TB

Also thought initially it would be a wise step toward upgrading the engine.

I dont want carbs,

 

[Alphabettispaghetti]

I can’t see there being ‘no increase’ in performance. Some cast flat top pistons(£350ish) and a cam (£3-400) would be worth doing at the same time

 

[jonbills]

I read it before but it doesn't give a great deal of detail, especially regarding any head work.

"This engine is sold ONLY as a complete assembly. Base price includes, Block, Forged pistons, Billet connecting rods, and rod and main bearings. Customer supplies cylinder head core, does not include Diesel crankshaft.

Engine long blocks starting at $8900"

Do you pay extra for the crank?

Yeah, doesn't make a huge amount of sense.

 

[Mark N]

I have opted for EZ EFI.

I also went with the FAST system from Z Car Depot.
It is easy enough to fit/set up and also tidies up the engine bay.
I also fitted their fuel rail and a set of modern injectors along with a throttle body from eBay.
I haven't had much of a chance to drive it as the car has been stuck in Cyprus for the last 18 months.
The FAST system greatly improves starting and I'm sure that removing the AFM would have at least some improvement on airflow.

... I thought Evo's were expensive to mod

Tuning NA cars is always expensive for relatively small gains in comparison to turbo cars.

Was the engine running before you pulled it?

 

[M-j-b]

I also went with the FAST system from Z Car Depot.
It is easy enough to fit/set up and also tidies up the engine bay.
I also fitted their fuel rail and a set of modern injectors along with a throttle body from eBay.
I haven't had much of a chance to drive it as the car has been stuck in Cyprus for the last 18 months.
The FAST system greatly improves starting and I'm sure that removing the AFM would have at least some improvement on airflow.



Tuning NA cars is always expensive for relatively small gains in comparison to turbo cars.

Was the engine running before you pulled it?

I had it "running" off carb cleaner..
Low mileage motor.

 

[Mark N]

I had it "running" off carb cleaner..
Low mileage motor.

Did you do a compression or leak down test before you pulled the engine?
That might give you an idea of 'must have' as opposed to 'nice to have' before you put the engine back in.

 

[M-j-b]

Did you do a compression or leak down test before you pulled the engine?
That might give you an idea of 'must have' as opposed to 'nice to have' before you put the engine back in.

Engine is off to the my engine company next week, they are going to strip and then we can make some decisions.

I didnt check compression as I dont have a setup to do.. just never been involved with internals.

Thanks for the advice,
I will post with more info once I know more.

I was amazed how easily the header and intake etc came off.
That's one good thing