totempalen
18th January 2023, 00:25
In this thread I will be sharing my experience with head swapping my 1.4l TU3JP Saxo.
The result
I went from ~85hp with a (proper)cold air intake and decat to ~105hp after the headswap. From the stock 75hp to 105hp is a 40% gain. :wacko:
Yellow/green is before the headswap and remap. Blue is afterwards. HP on the left, Nm on the right.
https://cdn.discordapp.com/attachments/593818943198855194/1065046084935766116/IMG_20230108_230908.jpg
Mods
To achieve 105hp the follow mods were done to the car.
TU5JP cylinderhead (black top)
TU5JP intake manifold + throttle body
TU5JP injectors
piper 4-1 exhaust manifold
GRAMS Racing exhaust
ME221 Gen 2 stand alone ecu. Installed and mapped by Van Drie Performance
Bosch MAP sensor
Bosch 4.2 LSU wideband sensor
Assessment
The interesting question here is ofcourse. Where did I make the gains?
Had we done all the mods except for the head swap, how much power would it have made. A really good question, unfortunately I have no good answer for this. I would like to think the head swap played a big role. But it's hard to say.
Notes
My 1.4 block had a silvertop roller rocker cylinderhead. The 1.6 head is a blacktop solid rocker.
The valve sizes for the 1.4 silvertop are as follows:
Intake: 36.7mm / 36.8mm (I found conflicting info on this)
Exhaust: 29.4mm
Now for the 1.6 blacktop.
Intake: 39.4mm
Exhaust: 31.3mm
Meaning we have a difference of:
Intake: 2.6mm - 2.7mm
Exhaust: 1.9mm
Compression
Unfortunately I did not compression test the engine before doing the headswap, so I have no numbers on this. After the headswap I have done a compression test and got 3 cylinders at ~12bar and 1 cylinder at ~11.5 bar. Keep in mind this is measured compression. This is not representative of the static compression ratio.
I cannot say with certainty what affect this modification has had on the compression ratio.
Parts numbers
Old cylinderhead, TU3JP silvertop from 2000.
0200 AR
New cylinderhead, TU5JP blacktop from 1998
0200 G4
Sealing and size issues
When swapping the 1.6 head on the 1.4 engine block we run into a problem.
The inner bore of the block and head do not match. This results into something like illustrated here:
https://cdn.discordapp.com/attachments/593818943198855194/1065061396146040994/image.png
This picture is exaggerated, but you get the idea. The inner edge of the head mates with the outer edge of the block.
This mismatch leads to a potential for headgasket issues. With the TU3JP being an open deck block, the cylinder wall is all you get. beyond that is coolant. So the (now) thin layer where the outer edge of the block and inner edge of the head meet, is all you get to seal them together.
I personally used an oem 1.6 MLS headgasket and thus far I have not had any issues. I will continue to closely monitor my oil and coolant. This is now definitely a weak link in my engine.
But why?
There's a few different reasons one might do this:
1. Legality
Engine swaps can be a legal hassle in a lot of countries.
2. Ease
Swapping a whole engine can be very daunting for beginners such as myself. Comparatively, swapping a cylinderhead is much easier.
3. Weight
The aluminium open deck 1.4 is significantly lighter than the cast iron closed deck 1.6 blocks.
The result
I went from ~85hp with a (proper)cold air intake and decat to ~105hp after the headswap. From the stock 75hp to 105hp is a 40% gain. :wacko:
Yellow/green is before the headswap and remap. Blue is afterwards. HP on the left, Nm on the right.
https://cdn.discordapp.com/attachments/593818943198855194/1065046084935766116/IMG_20230108_230908.jpg
Mods
To achieve 105hp the follow mods were done to the car.
TU5JP cylinderhead (black top)
TU5JP intake manifold + throttle body
TU5JP injectors
piper 4-1 exhaust manifold
GRAMS Racing exhaust
ME221 Gen 2 stand alone ecu. Installed and mapped by Van Drie Performance
Bosch MAP sensor
Bosch 4.2 LSU wideband sensor
Assessment
The interesting question here is ofcourse. Where did I make the gains?
Had we done all the mods except for the head swap, how much power would it have made. A really good question, unfortunately I have no good answer for this. I would like to think the head swap played a big role. But it's hard to say.
Notes
My 1.4 block had a silvertop roller rocker cylinderhead. The 1.6 head is a blacktop solid rocker.
The valve sizes for the 1.4 silvertop are as follows:
Intake: 36.7mm / 36.8mm (I found conflicting info on this)
Exhaust: 29.4mm
Now for the 1.6 blacktop.
Intake: 39.4mm
Exhaust: 31.3mm
Meaning we have a difference of:
Intake: 2.6mm - 2.7mm
Exhaust: 1.9mm
Compression
Unfortunately I did not compression test the engine before doing the headswap, so I have no numbers on this. After the headswap I have done a compression test and got 3 cylinders at ~12bar and 1 cylinder at ~11.5 bar. Keep in mind this is measured compression. This is not representative of the static compression ratio.
I cannot say with certainty what affect this modification has had on the compression ratio.
Parts numbers
Old cylinderhead, TU3JP silvertop from 2000.
0200 AR
New cylinderhead, TU5JP blacktop from 1998
0200 G4
Sealing and size issues
When swapping the 1.6 head on the 1.4 engine block we run into a problem.
The inner bore of the block and head do not match. This results into something like illustrated here:
https://cdn.discordapp.com/attachments/593818943198855194/1065061396146040994/image.png
This picture is exaggerated, but you get the idea. The inner edge of the head mates with the outer edge of the block.
This mismatch leads to a potential for headgasket issues. With the TU3JP being an open deck block, the cylinder wall is all you get. beyond that is coolant. So the (now) thin layer where the outer edge of the block and inner edge of the head meet, is all you get to seal them together.
I personally used an oem 1.6 MLS headgasket and thus far I have not had any issues. I will continue to closely monitor my oil and coolant. This is now definitely a weak link in my engine.
But why?
There's a few different reasons one might do this:
1. Legality
Engine swaps can be a legal hassle in a lot of countries.
2. Ease
Swapping a whole engine can be very daunting for beginners such as myself. Comparatively, swapping a cylinderhead is much easier.
3. Weight
The aluminium open deck 1.4 is significantly lighter than the cast iron closed deck 1.6 blocks.