Engine bore?

TigZy · Post by **TigZy** » Tue Sep 07, 2004 8:46 pm

Hi there.

While I had this idea in mind for the Type-R I was originally going to buy, I was curious as to whether anybody knew of any technical documents or people who had bored out their FTO to a higher engine capacity? I know that in the Type-R department (2000 and below models) the engine boring out was limited (1.8L > 2L on a b18c3 was the safest to go to), but maybe the gain on an FTO GPX would be larger? Any help would be appreciated

Cheers!
-TigZy

salacious · Post by **salacious** » Tue Sep 07, 2004 11:52 pm

I only know of one owner who has his engine bored out, he is in Japan and the website doesn't really go into much detail on it. He used to have a little more info in English but it is a 2.2L. Good luck with reading Japanese

http://www.geocities.co.jp/MotorCity-Circuit/1515/

TigZy · Post by **TigZy** » Wed Sep 08, 2004 11:29 am

Thanks for the help

He's got a nice FTO though... anything that will run a quarter mile under 13 seconds has my respects :p
Looks like I'll go speak to the guys at BD4's and see if they know how to do it.
Cheers!
-TigZy

HRD2BQT · Post by **HRD2BQT** » Wed Sep 08, 2004 3:03 pm

have u ever considered doing frankie style?

swap your existing 6A12 Block to its bigger brother 6A13 Block. I dont know how much work is need to be done by doing this but I'm sure it'll be more practical than boring your existing ones.

Goodluck in finding one though....rare as!~

Chiangstar · Post by **Chiangstar** » Wed Sep 08, 2004 3:36 pm

i think the 6a13 block is actually taller than the 6a12 block... dont quote me on that.... but i was looking into it a while back and it actually is a lot more work and $$ as it seems to be...not just a straight swap...

simon

HRD2BQT · Post by **HRD2BQT** » Wed Sep 08, 2004 4:55 pm

yeah it is taller but one of the guy from this forum has done the full 6A13 TT swap into his FTO so i dont think it' will be a problem.

As i said, im not really sure how much work is need to be done to do this. Being this two block is in d same 6A family - I'm quite sure this is far easier option than boring it out. Just to my idea anyway....

another option i could think off is using the crank, rod etc etc off 6A13. Basically simlar process to stoking d motor, but one thing 2 quote to is that 6A13 is design for Turbo (low comp), not sure if this can handle high compression head of the 6A12MIVEC.

some other guys in this forum may be able to explain this concepts.

TigZy · Post by **TigZy** » Wed Sep 08, 2004 6:17 pm

Cheers for the help! I might start keeping an eye on jap import wreckers to see what I can find

Anyone else want to add their two cents?

-TigZy

salacious · Post by **salacious** » Thu Sep 09, 2004 12:59 am

Getting it bored is expensive since you'll need custom made pistons. You can get oversized pistons but at most you can increase the engine up to a 2.1 L. If you were turbo charging (over 9psi) it at the same time it would make sense since you'd need a forged pistons to take the boost.

dannyboyau · Post by **dannyboyau** » Wed Sep 15, 2004 2:20 am

HRD2BQT wrote:yeah it is taller but one of the guy from this forum has done the full 6A13 TT swap into his FTO so i dont think it' will be a problem..

Yes it is taller but it fits under the bonnet just if you leave the original engine cover off

HRD2BQT wrote:As i said, im not really sure how much work is need to be done to do this. Being this two block is in d same 6A family - I'm quite sure this is far easier option than boring it out. Just to my idea anyway.....

there is a 6A13 non turbo engine so if you were to get that and put the 6A12 mivec heads on it you wouldnt need to change your pistons and rods.

HRD2BQT wrote:another option i could think off is using the crank, rod etc etc off 6A13. Basically simlar process to stoking d motor, but one thing 2 quote to is that 6A13 is design for Turbo (low comp), not sure if this can handle high compression head of the 6A12MIVEC.

I have been looking into this and will let you know when i know if it is possible.

Stay tuned

HRD2BQT · Post by **HRD2BQT** » Thu Sep 16, 2004 11:02 am

Thankx dude.....looking forward to your update!

JagerMarty · Post by **JagerMarty** » Tue Sep 21, 2004 10:41 am

I know there is an Albury based FTO owner who has reboared his engine.
Don't know the spec's but apparently he's had a great result with it.
Unfortunately I don't think he gets on here so info is limited.

wildfaye · Post by **wildfaye** » Tue Sep 21, 2004 12:10 pm

How about a bottom 6a13 block + 6a12 mivec head.
rebored out to 1mm bigger using stock oversized mit pistons?
effectively meaning a 2.6-2.7L mivec?

Black_FTOGPX · Post by **Black_FTOGPX** » Tue Sep 21, 2004 12:15 pm

I know this may be a dumb question, but has anybody looked at getting a custom block casted? As this way you could have the bore huge and the stroke the same, so the engine would not be taller. So you could have a 2.5 lt without any clearance problems

salacious · Post by **salacious** » Tue Sep 21, 2004 9:47 pm

The redline on the 6A13 I think is either 6.5 or 7K rpm which I think is down to the crank. If you rev it higher it might fail. This is one advantage of the 6A12

dannyboyau · Post by **dannyboyau** » Wed Sep 22, 2004 2:05 am

salacious wrote:The redline on the 6A13 I think is either 6.5 or 7K rpm which I think is down to the crank. If you rev it higher it might fail. This is one advantage of the 6A12

The 6A12 and 6A13 cranks are almost identical except for the stroke

I redline for the VR4 is 7500 i have my 6A13 Rev limiter set to 8500 and i have hit the rev limiter many times with 18 Lb boost, the only thing that has failed so far are the pistons due to detonation. I have been driving it now for over 18 months with about a total of 8 weeks off the road.

dannyboyau · Post by **dannyboyau** » Wed Sep 22, 2004 2:06 am

wildfaye wrote:How about a bottom 6a13 block + 6a12 mivec head.
rebored out to 1mm bigger using stock oversized mit pistons?
effectively meaning a 2.6-2.7L mivec?

1mm oversize will make the 6A13 a 2.55 Ltr engine

dannyboyau · Post by **dannyboyau** » Wed Sep 22, 2004 2:13 am

Black_FTOGPX wrote:I know this may be a dumb question, but has anybody looked at getting a custom block casted? As this way you could have the bore huge and the stroke the same, so the engine would not be taller. So you could have a 2.5 lt without any clearance problems

Custom block would be extremely expensive and not really worth the effort

Also the bore on the 6A12 is already bigger than the stroke, so you need to develop a stroker kit, so effectivly you need to cast a new crank or get the 6A12 crank stroked, It can be done but it is expensive as it involves getting the crank journals welded and then getting the crank reground to the desired stroke then you need to make custom rods designed and made to suit the new crank. Lots of time involved and time is money. Also the guys that do this type of work charge big dollars unless they are doing it for there own race cars or close mates.

Post by **smorison** » Wed Sep 22, 2004 11:27 am

dannyboyau wrote:
wildfaye wrote:How about a bottom 6a13 block + 6a12 mivec head.
rebored out to 1mm bigger using stock oversized mit pistons?
effectively meaning a 2.6-2.7L mivec?
1mm oversize will make the 6A13 a 2.55 Ltr engine

how hard is it to bolt the 6a12MIVEC heads onto the 6a13??
what's involved

Black_FTOGPX · Post by **Black_FTOGPX** » Wed Sep 22, 2004 11:34 am

I priced up a 6A13 block and it's looks like the cheapest place is NZ, they wanted $1500 for a Complete 6A13 Na SOHC engine or $750 for just the the block.

wildfaye · Post by **wildfaye** » Wed Sep 22, 2004 12:21 pm

I have absolutely no idea if it'll fit, but it sure sound delicious ain't it!