f2t pistons in fe3

**bakmans** · 7-29-07, 7:27

im building a fe3 turbo for my 1979 626 hardtop coupe and was wondering why nobody ( al least that i know of ) uses the f2t pistons in the fe3? the only difference is the way the pin in the piston is locked. on the fe3 its done with clamps and the f2t the pin is locked in the connectong rod. im planning on using the f2t piston on the fe3 rods and crank and blok the piston pin whith teflon caps on the end. this way i have a cheap and efective compression lowering piston.

any suggestions?

**fredio54** · 7-29-07, 9:39

i didnt realise that the deck height and pin size was the same?

i know the valve reliefs arent perfect, but, they are probably close enough.

might wanna use the NA ones though, as the turbo ones might make the compression too low. chamber volume is different...

interesting if no one noticed before.

fred.

**bakmans** · 7-29-07, 12:19

yeah the pins and the deck height are the same. i can make a photo if someones interested.
do the na pistons have a little hole to???
i was planning on using the turbo ones and shave the fe3 deck a bit to create a squish of 0,7mm. havent had the time to mesure the volumes and calculate the compression ratio though.
ill try to get some na pistons to!

**SixSick6** · 7-29-07, 12:25

Are you sure about that? Fraud and I and Fred were discussing that a few months ago. I'm trying to find the exact thread:
http://www.mx6.com/forums/fe-dohc/18...ml#post1813753 (did you know...)

http://www.mx6.com/forums/fe-dohc/34...ml#post1788205 (Fe3 Head?)

**bakmans** · 7-29-07, 12:44

100% sure about the pin size and the deck height.
didn't calculate the compression ratio yet.

the only difference is that the f2t piston pin is pressed or sqeezed ( dunno the correct word) on the connecting rod and the fe3 is full floating and locked with two springs on each side.
so if youd wanna put f2 pistons on a fe3 rod youd have to make teflon ( i use akulon) caps the slide in the side of the piston pin to keep it from scratching the cilinder. i never done this before but it seems alotta drag racers and race car builders do it to so i'll try it.

ill post a pic tomorrow! ( if i dont forget )

**bakmans** · 7-29-07, 12:50

Quote:

that a 94mm F2T crank, in a FE3 block using FE3 152mm rods, will give the 2.2DOHC a rod to stroke ratio that IS almost exactly the golden section! That has got to account for something... DaVinci inspired engine geomtries lol

i can say for sure that this doesn't work!
i had the fe3 and the f2t piston shoved on the same pin and the deck was excactly equal. so if you put it on the fe3 rod and crank you'll be OK. if you put in a f2t crank you for sure end up whith the pistons far above the fe3 deck.
the engine block of the fe3 is also lower as the f2t.

**bakmans** · 7-29-07, 12:58

another thought:

the fe3 crank is 86mm and the f2t crank is 94.

what if i put the fe3 rods whith f2t pistons on the f2t crank. acording to my calculations the pistons would rise 4mm above deck.
is it posible to shave about 3,7 mm of the f2t pistons?

**fredio54** · 7-29-07, 13:47

i strongly doubt it, the top of the fe3 piston is only about 5 or so thick maybe a bit more. at the best, it would leave it quite thin...

**bakmans** · 7-29-07, 14:12

im talking about the f2t piston. the f2t piston had a big sink in the middle of it. so the bottom of the piston is about 8mm deeper than the edges. so i can take off 4 mm easily whithout making the bottom thinner.

im gonna do some mesuring tomorrow

vaughn · 7-29-07, 14:39

Actually i was thinking the same thing, i have at this moment a FE3 piston and a n/a F2 piston side by side, everything is exactly the same, deck height, skirt ,ring grooves etc. i have never seen a FT2 piston,but this one has a large dish.it would make an excellent piston for a turbo FE3. i have found a difference in id of the pins, which would be a better choice, the two id's of the FE3 pins i have are13mm and 14mm??

**bakmans** · 7-29-07, 15:05

so by id you mean internal diameter?
ifso i would take the 13mm. but i doubt a 14mm would brake. i never took a close look to the f2 na piston but the f2t also has a big dish in it. i guess its bout the same as the na dish only deeper.
they also sell cupper gaskets for the fe3 that are bout 1.6mm thick. so when your piston is 4mm above deck that makes 4-1,6(gasket)-0,7(squish) = 1,7 mm.
so if you'd shave 1,7mm of the stock f2 ( na or turbo) you have a perfect squish. and by estimation i think the f2t piston would make a excellent piston for a stroked fe3 turbo this way. of course the volume of the fe3 head is slighly more than the f2t head ( 4valves compared to 3) but shaving 1,7mm of the piston edges would make up for that.
my engines are @ the shop i work. ill do some messuring tomorrow!

**mazda-head** · 7-29-07, 15:09

yea it;d be excellent if you're cool with a 5.5 or 6:1 compression ratio..............

**mazda-head** · 7-29-07, 15:10

86mm stroke and the F2T piston dish = unreasonably low CR , even if you shave.

**bakmans** · 7-29-07, 15:29

no were talking about a f2t crank in a fe3 block with fe3 rods and shaved f2t pistons

**proberider** · 7-29-07, 15:43

For what it would cost to shave the pistons, you may as well buy custom ones, and feel safe.

7-29-07, 7:27	#1 (permalink)
bakmans Join Date: Mar 2006 Location: uden, holland Age: 26 iTrader: (1)	f2t pistons in fe3 im building a fe3 turbo for my 1979 626 hardtop coupe and was wondering why nobody ( al least that i know of ) uses the f2t pistons in the fe3? the only difference is the way the pin in the piston is locked. on the fe3 its done with clamps and the f2t the pin is locked in the connectong rod. im planning on using the f2t piston on the fe3 rods and crank and blok the piston pin whith teflon caps on the end. this way i have a cheap and efective compression lowering piston. any suggestions?

7-29-07, 9:39	#2 (permalink)
fredio54 Join Date: Aug 2004 Location: Auckland, New Zealand iTrader: (1)	i didnt realise that the deck height and pin size was the same? i know the valve reliefs arent perfect, but, they are probably close enough. might wanna use the NA ones though, as the turbo ones might make the compression too low. chamber volume is different... interesting if no one noticed before. fred.
	DIYEFI.org - TRUE DIY engine management Mazda FE3/FE-DOHC Master Index Thread (work in progress) Mazda truck with FE-DOHC/FE3 "BIG like your house" Holset Turbo drinking 2.2 litres of fuel per minute ~= 385hp crank RIP SleepCounter :-( we will miss you! - RIP fredio54 :-( will we miss you?

7-29-07, 13:47	#8 (permalink)
fredio54 Join Date: Aug 2004 Location: Auckland, New Zealand iTrader: (1)	i strongly doubt it, the top of the fe3 piston is only about 5 or so thick maybe a bit more. at the best, it would leave it quite thin...
	DIYEFI.org - TRUE DIY engine management Mazda FE3/FE-DOHC Master Index Thread (work in progress) Mazda truck with FE-DOHC/FE3 "BIG like your house" Holset Turbo drinking 2.2 litres of fuel per minute ~= 385hp crank RIP SleepCounter :-( we will miss you! - RIP fredio54 :-( will we miss you?

7-29-07, 14:39	#10 (permalink)
vaughn New Member Join Date: Nov 2006 Location: cape town, south africa Age: 42 iTrader: (0)	FE3N vs F2 Actually i was thinking the same thing, i have at this moment a FE3 piston and a n/a F2 piston side by side, everything is exactly the same, deck height, skirt ,ring grooves etc. i have never seen a FT2 piston,but this one has a large dish.it would make an excellent piston for a turbo FE3. i have found a difference in id of the pins, which would be a better choice, the two id's of the FE3 pins i have are13mm and 14mm??

7-29-07, 12:19	#3 (permalink)
bakmans Join Date: Mar 2006 Location: uden, holland Age: 26 iTrader: (1)	yeah the pins and the deck height are the same. i can make a photo if someones interested. do the na pistons have a little hole to??? i was planning on using the turbo ones and shave the fe3 deck a bit to create a squish of 0,7mm. havent had the time to mesure the volumes and calculate the compression ratio though. ill try to get some na pistons to!

7-29-07, 12:44	#5 (permalink)
bakmans Join Date: Mar 2006 Location: uden, holland Age: 26 iTrader: (1)	100% sure about the pin size and the deck height. didn't calculate the compression ratio yet. the only difference is that the f2t piston pin is pressed or sqeezed ( dunno the correct word) on the connecting rod and the fe3 is full floating and locked with two springs on each side. so if youd wanna put f2 pistons on a fe3 rod youd have to make teflon ( i use akulon) caps the slide in the side of the piston pin to keep it from scratching the cilinder. i never done this before but it seems alotta drag racers and race car builders do it to so i'll try it. ill post a pic tomorrow! ( if i dont forget )

7-29-07, 12:58	#7 (permalink)
bakmans Join Date: Mar 2006 Location: uden, holland Age: 26 iTrader: (1)	another thought: the fe3 crank is 86mm and the f2t crank is 94. what if i put the fe3 rods whith f2t pistons on the f2t crank. acording to my calculations the pistons would rise 4mm above deck. is it posible to shave about 3,7 mm of the f2t pistons?

7-29-07, 14:12	#9 (permalink)
bakmans Join Date: Mar 2006 Location: uden, holland Age: 26 iTrader: (1)	im talking about the f2t piston. the f2t piston had a big sink in the middle of it. so the bottom of the piston is about 8mm deeper than the edges. so i can take off 4 mm easily whithout making the bottom thinner. im gonna do some mesuring tomorrow

7-29-07, 15:05	#11 (permalink)
bakmans Join Date: Mar 2006 Location: uden, holland Age: 26 iTrader: (1)	so by id you mean internal diameter? ifso i would take the 13mm. but i doubt a 14mm would brake. i never took a close look to the f2 na piston but the f2t also has a big dish in it. i guess its bout the same as the na dish only deeper. they also sell cupper gaskets for the fe3 that are bout 1.6mm thick. so when your piston is 4mm above deck that makes 4-1,6(gasket)-0,7(squish) = 1,7 mm. so if you'd shave 1,7mm of the stock f2 ( na or turbo) you have a perfect squish. and by estimation i think the f2t piston would make a excellent piston for a stroked fe3 turbo this way. of course the volume of the fe3 head is slighly more than the f2t head ( 4valves compared to 3) but shaving 1,7mm of the piston edges would make up for that. my engines are @ the shop i work. ill do some messuring tomorrow!

7-29-07, 15:09	#12 (permalink)
mazda-head Join Date: Feb 2001 Location: Canada Age: 28 iTrader: (0)	yea it;d be excellent if you're cool with a 5.5 or 6:1 compression ratio..............

7-29-07, 15:10	#13 (permalink)
mazda-head Join Date: Feb 2001 Location: Canada Age: 28 iTrader: (0)	86mm stroke and the F2T piston dish = unreasonably low CR , even if you shave.

7-29-07, 15:29	#14 (permalink)
bakmans Join Date: Mar 2006 Location: uden, holland Age: 26 iTrader: (1)	no were talking about a f2t crank in a fe3 block with fe3 rods and shaved f2t pistons

7-29-07, 15:43	#15 (permalink)
proberider Join Date: Sep 2004 Location: Lower Mt. Bethel, PA, USA Age: 33 iTrader: (4)	For what it would cost to shave the pistons, you may as well buy custom ones, and feel safe.