How far to overbore a 4G54

[balemo]

Hi Guys
Building new methanol speedway engine for my Siggy.
The only rules are mitsubishi block must be used everything else is open.
i have searched every where and i cant find anyone using bigger than 92mm how far can these blocks be bored safely. is 96 to much???
Im also considering using a 52 crank and build 2.4 screamer.if so which rods.??
Is there better blocks in the 54..

[A112H]

Have you thought about 4G63? A stock twin cam efi 63 will make more power than a stock carbi 54. The aftermarket world is your oyster for 63 parts, very different for 54 bits.

[balemo]

I havnt really because the carby 54 is a holly 500 on methanol so i get a great hp gain there..Also im an old fart thats on a tight budget and not really up with the efi world yet.
I get sponsored for my machine work and cost price engine bits.
I was hoping to build a big cube hauler rather than the 8000rpm 4g52

[A112H]

My 54 runs strong to 7500 and is a pretty basic tune but has bags of torque.
My old man runs a speedway side car and would love the torque in his bike I get in the old Astron, lol

[balemo]

Are they happy to run up there consistantly

[A112H]

Every time I used second, lol.

[Scorpma82]

i think from memory, Falcon 6cyl use 93mm pistons.....but i dont know anyting about the gudgon pins, skirt length or anything like that sorry


(I don't know how true this is but:) I've heard the Charger 265 hemi rods do bolt up to a 2L crank and are much stronger than factory rods as they are shotpeened from factory

Also, running methanol and tight budget are rarely used in the same sentence.....but jeez i hope u make it work lol
(how much is a L of Methanol these days?)

Lemme know how you go with the machining.......im planning on building a 3L Astron motor and fell into the same trap of piston sizes

There used to be a fabulous websute called Carbuddy.com.au that had all these specs for every australian sold car dating back to the 50's......but the bastards changed the format on the site and now its useless

[balemo]

3f toyota is 92 +1=93 pin is right just needs a bit turned of the top to get back to deck hieght. problemis i cant find out haw far we can bore safely??
I allready have a 2.6 methanol motor and its only $210 for 205 liter drum.
I cant afford to start again with EFI and motec computers etc etc.
Thats why im try to get something different with the g54 .

[Superscan811]

I'm currently building a few high compression astron engines, using Toyota 22R pistons (92.5mm). They have a 3mm higher compression height than the standard Astron pistons and a 24.7cc dome.

There are also a few crank options available.
1. A 4G52 2.0L crank, 90mm stroke.
2. A 4G54 2.6L crank, 98mm stroke.
3. A 4D56 2.5L crank, 95mm stroke, but the mains need to be turned down from 66mm to 60mm.

The 22R pistons with a 2L crank, M7 head decked 2mm, Block decked around 1mm (pistons 0.25mm above deck), you now have a 2.4L with a 14:1 comp ratio.

The 22R pistons with the modified 4D56 crank, M7 head decked 2mm, approx 2mm copper head gasket, you now have a 2.5L with a Comp ratio around 15:1

The 22R pistons with the edged beveled to match the head, 2.6L crank, M7 magna head Not decked, you now have a 2.6L with a comp ratio around 16:1

Food for thought.

Cheers.

[Scorpma82]

oh i hope u'll be running twin side drughts.....imagine the howl of that thing around the speedway