Borring

jdallis33026 · Post by **jdallis33026** » February 2nd, 2007, 3:58 pm

Can the 2.5 Klze be bored out to increcess displacement. I have seen the walls of the cyl. and they look pretty thin. so I don't know it they can be made larger.

Teqnyck · Post by **Teqnyck** » February 3rd, 2007, 11:29 am

There was a fella on Probetalk.com that bored his DE out, I wanna say it was .60 over, but it might have been .40. Either way, he had trouble with the car overheating. Granted, he had fully built internals and was running 16psi of boost. But still, the theory is that if you bring the combustion any closer to the water jacket than it already is, the car will overheat. That is just one case, though.

PATDIESEL · Post by **PATDIESEL** » February 3rd, 2007, 3:22 pm

There are stroker kits that bring the motor to something like 2.8L. I;ve heard they run well. Check on probetalk for a stroker kit for more info.

Nd4SpdSe · Post by **Nd4SpdSe** » February 3rd, 2007, 3:31 pm

Apparently Mazda sells a 0.50 kit for the 2.5's. Guy on ProbeTalk was selling it late last year, got it from CorkSport. I was temptedto buy it, he ways saying it was for a ZE, but the pistons looked like it was for a DE

I was doing some research on ProbeTalk. For what I found, they discouraged stroking since it works against the motors high-reving nature and design

kiwi_MX3 · Post by **kiwi_MX3** » February 3rd, 2007, 3:39 pm

I have bored my motor out to 88mm making it a 2.7L

Yes there is a increase in thermal displacement from the
cylinder walls.

but for racing its fine, as the track is only 30minutes away and ive
added a external oil cooler for the block which seems to help.

Teqnyck · Post by **Teqnyck** » February 5th, 2007, 11:09 am

Yeah! ^^^ I'm glad you stepped in, kiwi. You've got a real hybrid of parts going on in your car. Something like 400 stroker rods and 300zx pistons, right? Are you able to use regular engine coolant, or do you have to use water for more conductivity?

Steeb · Post by **Steeb** » February 5th, 2007, 11:38 am

i wonder if his thermostat was working properly or if maybe an upgraded radiator might have helped. with his overheating issue

kiwi_MX3 · Post by **kiwi_MX3** » February 5th, 2007, 3:19 pm

ford 5.4 rod's chevy big ends
Toyota 2VZ-FE Piston's ( modified to KLZE Spec )
shaved and "O" ringed heads.

I don't run a thermostat, i have a standard MX3 Radiator and run a
external oil cooler, antifreeze and inhibitor.

for the drag strip i have a second external electrical waterpump to
curculate the coolant while the engine is turnned off in the staging lanes
as most of us push our cars forward.

My motor does'nt over heat, but like all klze's it runs very warm
and over long distance ( and sucks gas like you would'nt belive! )
a swap to a craig davis external water pump i would think would solve
the issue as i have under drive pulleys on the crank and water pump.

Teqnyck · Post by **Teqnyck** » February 6th, 2007, 6:27 pm

Ah, I didn't know you were using Toyota pistons. How is that setup working for you?

mx3autozam · Post by **mx3autozam** » February 6th, 2007, 10:48 pm

Nd4SpdSe wrote:Apparently Mazda sells a 0.50 kit for the 2.5's. Guy on ProbeTalk was selling it late last year, got it from CorkSport. I was temptedto buy it, he ways saying it was for a ZE, but the pistons looked like it was for a DE

I was doing some research on ProbeTalk. For what I found, they discouraged stroking since it works against the motors high-reving nature and design

why would they discourage from stroking a motor because of its high reving nature. if you were to make the sroke smaller it would love higher rves even more!

kiwi_MX3 · Post by **kiwi_MX3** » February 7th, 2007, 3:46 am

Teqnyck wrote:Ah, I didn't know you were using Toyota pistons. How is that setup working for you?

I had to mod the piston's they are cheap aftermarket replacements
for the 2VZ-FE at 350nz for a set of 6 inculding a 21mm wrist pin
where as toyota wanted 185nz per piston! ekkk!

just decked the crown and shorted the skirt and they are doing fine
for a NA motor.

ScooterBovine · Post by **ScooterBovine** » February 7th, 2007, 4:29 am

kiwi_MX3 wrote: just decked the crown and shorted the skirt and they are doing fine
for a NA motor.

I don't even know what that means!

kiwi_MX3 · Post by **kiwi_MX3** » February 7th, 2007, 2:41 pm

ScooterBovine wrote:
kiwi_MX3 wrote: just decked the crown and shorted the skirt and they are doing fine
for a NA motor.
I don't even know what that means!

well at least someone is honest.

Decking is a term for machining " i had my engine block decked"
which set's it to the right height.

the piston itself has a number of areas, the crown being the top
of the piston, ring lands being where the rings live and the skirt, which
is the lower part that guides the piston in the bore.

jdallis33026 · Post by **jdallis33026** » February 7th, 2007, 4:41 pm

Thanks Very informative! If your intersted I am not planning to do this for a # of years.