I know that ideally a race engine would most likely either run a pure restrictor plate or nothing combined with a variable speed EWP

I'm not quite ready for the jump to EWP just yet and I fear that a restrictor plate in an engine which is mainly used as a road vehicle has too many issues - mainly failure to reach working temp most of the time, running cold maps for longer etc etc

So
I have an old 81C thermostat
I have a drill and selection of drills
I have an idea

The stock 'stat stays shut to ~80C then opens with a bang creating thermal shock in the block
What if I were to chain drill a few holes round the circumference. Think jiggle pin hole but a few more of larger diameter
This way the stock stat would still flow some water round the block during warmup but should still reach operating temp reasonably fast.

Brilliant stroke of innovating genius?
Or insane ramblings of a complete tool?

Answers on a postcard please

brilliant stroke of innovating genius

_________________
ST165 turbo 4WD
ST185 GT-FOUR RC Carlos Sainz Limited Edition 825•5000
ST185 turbo 4WD Carlos Sainz Limited Edition 2541•5000

So water would pass wound the coolant system and through the rad while the engine was cold because the thermostat wasn't stopping it properly?


To my mind the issue is in finding the balance point between longer warmup times and a decent benefit as far as flow goes. If the flow is good enough to prevent thermal shock (ie temp on both sides of the stat is close to the same) then surely that means the flow is good enough to lose heat through the rad. Causing the problem of longer warmup times.

I guess the idea could work, but getting the balance is key. Too few holes, no penefit. Too many, longer warmup times. Whether there is a happy medium to be found is more than I can tell ya

_________________
JDM ST205 (286bhp and 281lb/ft)
JDM ST202 (Finally sold )
1982 Pontiac Trans Am 5.7L V8 (See my website)

quite correct Paul

There will be an impact on warmup but it's (hopefully) not as bad as a straight restrictor plate. I hope

Think the stat gradually opens rather than the "bang" open decribed above.

Believe the drilling of an additional one or 2 3mm holes is fairly common practice on higher output cars?

_________________
Kris
95 ST205 - slept for 10 years, now waking up...
Avensis
http://www.gtfours.co.uk
_______________________________________
Turbocharging - the replacement for displacement

No bang, who told you, that bang takes the place?
It's consequent opening of the valve..

TMM it's no need to do smth with it, especially to install stuff like TRD with 71 (IIRC) level..

Normal atomisation of fuel goes at grade between 75-80, if to keep this range all will be fine..

_________________
"To raven, to do a crap, to sward a pinkie - just that are the needs of a real man"

(E.M.Remark, "Three camrades")

Kris is quite correct...'stat gradually opens..'
Easy check is to put a thermostat in a bowl or cup.
Pour boiling water over it.
Observe the results as the thermostat gradually opens.

Very good method for testing if a thermostat is working/opening correctly.

_________________
Vice Chairman
1990 White UK Celica ST185 - Project DTM
1997 Cream BMW R1200C (as seen in James Bond "Tomorrow Never Dies")
2005 Jaguar X-type 3.0 Sovereign AWD Automatic
Blood Bikes - https://www.freewheelers.org.uk/

It's still quite a bang in thermal shock terms though. It might only open a small amount but it's very suddenly going to dump cold water from the non circulating rad into a hot engine block

You reckon its that bad Steve?
I'm wish I'd kept my old Chemistry set...I'm sure I could have rigged something up and done a test

_________________
Vice Chairman
1990 White UK Celica ST185 - Project DTM
1997 Cream BMW R1200C (as seen in James Bond "Tomorrow Never Dies")
2005 Jaguar X-type 3.0 Sovereign AWD Automatic
Blood Bikes - https://www.freewheelers.org.uk/

THAT bad - probably not on it's own

One of a number of bad things that's simply addressed - yes

Sounds like you're better off removing the thermostat entirely and fitting some kind of retractable rediator cover/cowling. That way the water never has to have a temperature difference point to point

_________________
JDM ST205 (286bhp and 281lb/ft)
JDM ST202 (Finally sold )
1982 Pontiac Trans Am 5.7L V8 (See my website)

I hope that the little holes I have will allow water flow through the rad at least warming the contents of that while cooling the block a little

I doubt it's perfect but it must reduce the delta between rad and block quite a bit