To interfear or not - Interference engines
To interfear or not - Interference engines
It is only important to know once your cam belt/chain snaps - is it terminal to your engine or not?
So what does all this mean?:
In an interference design, the valves open enough into the cylinder milliseconds after the piston starts pulling back.
These engines depend upon the proper operation of the timing belt to ensure that the piston and valve don't try to be in the same place at the same time.
Hence the disadvantage this type of design has when a timing belt breaks suddenly. This is generally a bad, bad thing.
A non-interference design means the valves don't occupy the same place as the piston, a broken timing belt will mean your engine stops but probably not a lot else - simples!!
So what type is under your bonnet?
As for Supras...
4M- ???????
5M-GE is non interference
6M-GE Probably not interference.
7M-GE and 7M-GTE are non interference...
1jz-GTE ?????? STAV will know!!
2jz-GE and 2jz-GTE are non interference UNLESS VVTI then they are interference.
Please add to the list, we may have a fair database in a few months????
"Life's goal is not to arrive safely at the grave in a well preserved body. But, rather to skid in sideways........
totally worn out and broken, shouting 'Holy ****, WHAT A RIDE!'"
FirebirdPhil
23-08-2020, 04:31 AM #1So there are 2 types of engine "Interference and -Non Interference" - OK Mazda have a rotary design - that's another story.
It is only important to know once your cam belt/chain snaps - is it terminal to your engine or not?
So what does all this mean?:
In an interference design, the valves open enough into the cylinder milliseconds after the piston starts pulling back.
These engines depend upon the proper operation of the timing belt to ensure that the piston and valve don't try to be in the same place at the same time.
Hence the disadvantage this type of design has when a timing belt breaks suddenly. This is generally a bad, bad thing.
A non-interference design means the valves don't occupy the same place as the piston, a broken timing belt will mean your engine stops but probably not a lot else - simples!!
So what type is under your bonnet?
As for Supras...
4M- ???????
5M-GE is non interference
6M-GE Probably not interference.
7M-GE and 7M-GTE are non interference...
1jz-GTE ?????? STAV will know!!
2jz-GE and 2jz-GTE are non interference UNLESS VVTI then they are interference.
Please add to the list, we may have a fair database in a few months????
"Life's goal is not to arrive safely at the grave in a well preserved body. But, rather to skid in sideways........
totally worn out and broken, shouting 'Holy ****, WHAT A RIDE!'"
FirebirdPhil 2jz-GE and 2jz-GTE are non interference UNLESS VVTI then they are interference.The GTE is non interference, but if you snap the timing belt on a GE you'll get a valve salad
Edit: Sorry, you're absolutely right. I was thinking about the IS300 which has the VVTi-version.
P.Lindblom
23-08-2020, 05:27 AM #2FirebirdPhil 2jz-GE and 2jz-GTE are non interference UNLESS VVTI then they are interference.The GTE is non interference, but if you snap the timing belt on a GE you'll get a valve salad
Edit: Sorry, you're absolutely right. I was thinking about the IS300 which has the VVTi-version.
[SIGPIC][/SIGPIC] [COLOR="DarkOrchid"]That symbol on the side of my door.. Definition by FirebirdPhil 'Translated it means -
"try to overtake - go on give it a go I dare you......." [/COLOR]
I'm not an Outlaw; I'm a Poutlaw! Purple Supras are the bestest! I love purple .. a lot lot lot
purplewitch
23-08-2020, 05:55 AM #3Phew.... when I read the title I thought you were announcing you'd joined Gary Glitter's fan club lol
[SIGPIC][/SIGPIC] [COLOR="DarkOrchid"]That symbol on the side of my door.. Definition by FirebirdPhil 'Translated it means -
"try to overtake - go on give it a go I dare you......." [/COLOR]
I'm not an Outlaw; I'm a Poutlaw! Purple Supras are the bestest! I love purple .. a lot lot lot
purplewitch Phew.... when I read the title I thought you were announcing you'd joined Gary Glitter's fan club lolor as it appears The Jimmy Saville fan club, (dirty *******)
1990 Eunos Roadster in Mariner DU blue
Cobalt cat back, Decat pipe, 15in Red Rota GT3 alloys, Toyo tyres, Lowered on Coil overs, Red anti roll bars, 14degree timing mod, white dash kit, illuminated side marker lights,
Halo ring headlights, OEM windblocker, Bluetooth streaming HU, Blue leather handbrake and gear lever gaitor, Centre brake/tail light mod, Blue velour door cards, Polished cam cover, Polished front strut bar, 4xheadrest speakers, JDM floor mats, Suede semi dish steering wheel,
purplewitch Phew.... when I read the title I thought you were announcing you'd joined Gary Glitter's fan club lolor as it appears The Jimmy Saville fan club, (dirty *******)
1990 Eunos Roadster in Mariner DU blue
Cobalt cat back, Decat pipe, 15in Red Rota GT3 alloys, Toyo tyres, Lowered on Coil overs, Red anti roll bars, 14degree timing mod, white dash kit, illuminated side marker lights,
Halo ring headlights, OEM windblocker, Bluetooth streaming HU, Blue leather handbrake and gear lever gaitor, Centre brake/tail light mod, Blue velour door cards, Polished cam cover, Polished front strut bar, 4xheadrest speakers, JDM floor mats, Suede semi dish steering wheel,
[SIGPIC][/SIGPIC] [COLOR="DarkOrchid"]That symbol on the side of my door.. Definition by FirebirdPhil 'Translated it means -
"try to overtake - go on give it a go I dare you......." [/COLOR]
I'm not an Outlaw; I'm a Poutlaw! Purple Supras are the bestest! I love purple .. a lot lot lot
purplewitch
23-08-2020, 07:12 AM #5He always was overly creepy, on tv and in person
[SIGPIC][/SIGPIC] [COLOR="DarkOrchid"]That symbol on the side of my door.. Definition by FirebirdPhil 'Translated it means -
"try to overtake - go on give it a go I dare you......." [/COLOR]
I'm not an Outlaw; I'm a Poutlaw! Purple Supras are the bestest! I love purple .. a lot lot lot
3S-GE and GTE are non-interference up until 1999 (BEAMS -GEs from the late JDM MK2 MR2, Rav4 and Altezza are interference, GTE from the Caldina is interference).
1UZ-FE is non-interference up until VVTi was introduced. Hence 2UZ and 3UZ are inteference as they are built around the same engine as the VVTi 1UZ.
It's worth knowing that Toyota's non interference design is only *just* non interference (and they seem to have stopped doing it now anyway). If your timing belt lets go above 3.5krpm your valves will probably be toast anyway, interference design or not!
3S-GE and GTE are non-interference up until 1999 (BEAMS -GEs from the late JDM MK2 MR2, Rav4 and Altezza are interference, GTE from the Caldina is interference).
1UZ-FE is non-interference up until VVTi was introduced. Hence 2UZ and 3UZ are inteference as they are built around the same engine as the VVTi 1UZ.
toxo It's worth knowing that Toyota's non interference design is only *just* non interference (and they seem to have stopped doing it now anyway). If your timing belt lets go above 3.5krpm your valves will probably be toast anyway, interference design or not!
3S-GE and GTE are non-interference up until 1999 (BEAMS -GEs from the late JDM MK2 MR2, Rav4 and Altezza are interference, GTE from the Caldina is interference).
1UZ-FE is non-interference up until VVTi was introduced. Hence 2UZ and 3UZ are inteference as they are built around the same engine as the VVTi 1UZ.
Nice one John. Very good information
1990 Eunos Roadster in Mariner DU blue
Cobalt cat back, Decat pipe, 15in Red Rota GT3 alloys, Toyo tyres, Lowered on Coil overs, Red anti roll bars, 14degree timing mod, white dash kit, illuminated side marker lights,
Halo ring headlights, OEM windblocker, Bluetooth streaming HU, Blue leather handbrake and gear lever gaitor, Centre brake/tail light mod, Blue velour door cards, Polished cam cover, Polished front strut bar, 4xheadrest speakers, JDM floor mats, Suede semi dish steering wheel,
toxo It's worth knowing that Toyota's non interference design is only *just* non interference (and they seem to have stopped doing it now anyway). If your timing belt lets go above 3.5krpm your valves will probably be toast anyway, interference design or not!
3S-GE and GTE are non-interference up until 1999 (BEAMS -GEs from the late JDM MK2 MR2, Rav4 and Altezza are interference, GTE from the Caldina is interference).
1UZ-FE is non-interference up until VVTi was introduced. Hence 2UZ and 3UZ are inteference as they are built around the same engine as the VVTi 1UZ.
Nice one John. Very good information
1990 Eunos Roadster in Mariner DU blue
Cobalt cat back, Decat pipe, 15in Red Rota GT3 alloys, Toyo tyres, Lowered on Coil overs, Red anti roll bars, 14degree timing mod, white dash kit, illuminated side marker lights,
Halo ring headlights, OEM windblocker, Bluetooth streaming HU, Blue leather handbrake and gear lever gaitor, Centre brake/tail light mod, Blue velour door cards, Polished cam cover, Polished front strut bar, 4xheadrest speakers, JDM floor mats, Suede semi dish steering wheel,
The belt looks like new - I assume a well worn belt (100K) will look knackered??
"Life's goal is not to arrive safely at the grave in a well preserved body. But, rather to skid in sideways........
totally worn out and broken, shouting 'Holy ****, WHAT A RIDE!'"
FirebirdPhil
23-08-2020, 09:26 AM #9I started this thread because the IS300 I have bought should in theory need a belt, the change isn't in the service history and the previous owner - admittedly only a short time didn't do it. I did phone Lexus Leeds who the majority of service history is with, they didn't do it, and the next 2 stamps reported a blank......
The belt looks like new - I assume a well worn belt (100K) will look knackered??
"Life's goal is not to arrive safely at the grave in a well preserved body. But, rather to skid in sideways........
totally worn out and broken, shouting 'Holy ****, WHAT A RIDE!'"
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