Bluetop Engine Rebuild multiple question Goal 150-160hp

[Project D]

(04-10-2021 07:31 PM)Hanzo Wrote:  [...]My goal is to get around 150hp. And maybe ITBs in the future (mostly for the sound )
[...]
My questions are
1. Are the above stats correct?
2. It seems that i can reach my power goals with the bluetop engine.
Or it wise to change to smallport?
3. I also want to change oil pump, water pump etc. I read that the 20V oilpump fits on any 4 AGE. Did anybody installed a 20V oil pump?
4. I also read on the garage 4AGE channel that there are different bigport head versions. Is that true?
5. Can anyone recommend a piston sets?
6. What is the max compression for a standard ECU? I read that 10,7-10,8:1 is possible with the standard ECU.
7. Do i need aftermarket ECU for ITBs?

1: Yes. 9.4:1 for bluetop worldwide except EU model (10:1), 10.3:1 are from a different bottom end (42/20mm instead of 40/18mm)
2: You can reach 150hp with your current engine, no issues.
One of my friends have 148hp with just a set of 264/256° HKS cams, 0.8mm head gasket and 0.5mm surfaced cylinder head. Nothing fancy, ZERO porting. (full martelius exhaust, stock intake and engine management)
3: Oil pump: 15100-19036 (latest 16v, 20v silvertop), Water pump: 16110-16010
4: If your car is from 83, you most likely have an early (nice) casting. So you don't have to worry about that.
5: 10:1 spec pistons 13101-16030-02 (don't forget the "-02") are still listed as available on Amayama
6: ECU don't care about the compression ratio of your engine. They are not AI, just electronic automaton who are made to run a set of parameters.
Once you start significantly modifying your engine, you get out of those parameters. So I would definitely recommend going for an aftermarket ECU. I would also replace the injectors.
7: YES ! Some peoples may claim running with ITB on the stock ECU, but there is a big difference between making an engine run and make it run PROPERLY !

(04-11-2021 05:28 AM)oldeskewltoy Wrote:  Some care should be used when discussing power ratings - engine power means very little in the real world, wheel horsepower is a far better tell. Wheel hp measured 1:1 (many 4th gears, but not all are 1:1)

While I agree that power at the wheel is a better tool to compare car to car performance, it's a BAD idea to refer to WHP when we are talking engine tuning. Transmission loss can be massively different between car to car.
If you are lucky you may be able to get 150whp with as little as 160hp, or as much as 190hp...