0 registered members (),
225
guests, and 2
spiders. |
Key:
Admin,
Global Mod,
Mod
|
|
Forums69
Topics113,624
Posts1,341,348
Members1,807
|
Most Online731 Jan 14th, 2020
|
|
|
Maximum bore diameter
#623738
03/06/2008 05:14
03/06/2008 05:14
|
TipoBoy
Unregistered
|
TipoBoy
Unregistered
|
What is the maximum safe bore diameter for the 20VT engine. The pistons I had fitted had a bore of 3.267" (83mm) and a clearance of 0.0030".
The bores are scratched and a hone might not be enough. Can they be made any larger?
Thanks
John
|
|
|
Re: Maximum bore diameter
[Re: ]
#623968
03/06/2008 14:11
03/06/2008 14:11
|
TurboJ
Unregistered
|
TurboJ
Unregistered
|
I think you can go 84mm absolute max but you need a custom headgasket as the standard one will protrude into the bore. If you already have 83mm pistons then I suggest you get another block, or worse case re-line the block you have.
|
|
|
Re: Maximum bore diameter
[Re: Flea]
#624019
03/06/2008 15:28
03/06/2008 15:28
|
TipoBoy
Unregistered
|
TipoBoy
Unregistered
|
Thanks. I checked with Barbz and you're right 83.5mm is the maximum. Requires a longer running in period with mineral oil.
John
|
|
|
Re: Maximum bore diameter
[Re: ]
#624023
03/06/2008 15:31
03/06/2008 15:31
|
eldinho
Unregistered
|
eldinho
Unregistered
|
so what cc will that take you to?
|
|
|
Re: Maximum bore diameter
[Re: ]
#624049
03/06/2008 16:25
03/06/2008 16:25
|
Joined: Dec 2005
Posts: 10,728 N.E Scotland
mattB
Club member 6
|
Club member 6
I AM a Coop
Joined: Dec 2005
Posts: 10,728
N.E Scotland
|
Maybe I missed it, but what was the damage to the pistons? If they’re re-usable isn’t it a better bet to ship out a replacement block from the UK and bore it out to match the pistons you already have? No idea on prices but I’d *guess* that might be cheaper than getting replacement pistons when the block is going to require some work anyway?
Death-rattle-tastic
|
|
|
Re: Maximum bore diameter
[Re: mattB]
#624189
03/06/2008 19:09
03/06/2008 19:09
|
TurboJ
Unregistered
|
TurboJ
Unregistered
|
WOW just saw that thread. That’s some serious det. Do you know what/how that happened? I know how you feel as my pistons also got messed due to incorrect clearance and incorrect DTA ECU timing. Looking at the damage I would say you better start ordering another block, I wouldn’t gamble an 83.5-84mm overbore.
|
|
|
Re: Maximum bore diameter
[Re: ]
#624271
03/06/2008 21:29
03/06/2008 21:29
|
TipoBoy
Unregistered
|
TipoBoy
Unregistered
|
The timing was okay. The first thing Lightspeed did was check the ECU signal with the timing mark on the timing pulley.
I agree, I don't think I want to risk an 83.5mm overbore. If the honing doesn't remove the scores then I'll talk to the builders about sleeving. Otherwise I might be able to get a friend who's moving here to put a spare block in his container!
John
|
|
|
Re: Maximum bore diameter
[Re: ]
#624423
04/06/2008 00:33
04/06/2008 00:33
|
TurboJ
Unregistered
|
TurboJ
Unregistered
|
Otherwise I might be able to get a friend who's moving here to put a spare block in his container!
John Better make it two to be safe
|
|
|
Re: Maximum bore diameter
[Re: ]
#624436
04/06/2008 00:51
04/06/2008 00:51
|
Trickymex
Unregistered
|
Trickymex
Unregistered
|
The place i use for rebores has the abilty to check the thickness of the walls on each bore before they are bored out
The main resaon for this is they do off-set boring as cast blocks all suffer from some sort of core shift, and this gives you the benifit of putting the bore dead in the middle of the bore casting.
Normally its not worth worrying about but if you are going to the outer limits of the bores then this can be quite helpfull as you will always get an equal thickness wall around the bore.
Also it will tell you before you have payed out for rebore if the block will go to that bore or not.
Not to mention finding out once the engine is fitted and running
Ricky
Last edited by Trickymex; 04/06/2008 00:52.
|
|
|
Re: Maximum bore diameter
[Re: ]
#624500
04/06/2008 09:27
04/06/2008 09:27
|
Squid
Unregistered
|
Squid
Unregistered
|
Last time I asked, CarlT was selling standard 20VT blocks for £125. So, if you can get it shipped to you cheaply, that would be your best option.
|
|
|
|