hi there guys,
i was just wandering some more info please on the modifcation on drilling say the 160 degree thermostat!

what does this mod do/help?

where/what part do you drill?

what size hole to drill?

how many holes do you drill?

is it worth while doing for any gain/help?

any photos at all please of it?

i remember tpis mentioning this mod once before and they do it i think!
thanks again guys!
cheers
glen
Australia

 

ttt

 

what do ya mean ttt?
is that all you got to say!
thanks
glen

 

Just drill a couple small holes on the flange. DO NOT touch any of the springs or filaments. Like 1/64th diameter bit. Position them 'front & back' -ish.

This does not affect fluid flow per se, but aids in 'burping' water from the system. If an air pocket were to develop at the top of the engine, it may lead to an improperly functioning of the Stat. The holes let the air out and into the radiator where they are easily passed thru the cap.

 

TTT = To The Top, as in the post going 'to the top'.

 

People do this to help get the question answered quickly.

 

hi there guys,
thanks for your explantion r.e ttt!
i didnt realize,sorry!

so is there any performance gain doing the drilling mod?

what would 1/64 size drill equal in mm diamter size please?

so is it reccomended or necessary to do this mod?

how many holes would you drill front and back?
ok thanks again guys!
you all been a great help!
glen
Australia

 

No performance gains and a total waste of time and energy.

PS==1/64" = diameter of a paperclip.

 

a 1mm or 2mm would be enough. I would not do more than 2 on near-ish opposite sides. It's not a 'technical driven' mod. It just helps burp air from the system. More useful in hot climates than cold, or so I have heard.

This is not a necessary mod, but a helpful one. Just like the throttle body coolant bypass. They don't really help performance as much as they help maintenance. Same goes for the rear diff drain plug kit.

 

Back in the day I cooked a motor because of a failed thermostat. From that day on I have always,always drilled four small hole. I have a 160 in the vette. On cool mornings it takes forever to warm up. Just yesterday temps here were in the low 30's. I drive 22 miles to work on the highway. Max temp 147. That can't be good. I think there's a stat that fails in the open position. I may try that one day

 

 

sxyvet, check my post in that other thread where you first asked Kopbet.

 

Some of the better 'stats come with a notch and do not need to be drilled.

 

 

so it sounds like after reading the above post that having a notch or holes drilled can help/work some!
cheers
glen

 

 

Well, ain't exactly correct.

If you block the coolant bypass hole, that's the 3/8s hole in the block where the water pump bolts on, the passenger side of the block. Look at a water pump, on the passenger side of the pump there are 3 holes instead of 2, 2 are for the bolts and guess what the 3rd is.

Fords and Dodges have a bypass hose on the TStat, Chevy puts it in the block.

This hole allows water to bypass in the block and helps the engine to warm up a bit faster. Blocking this hole allows the water pump to flow water more evenly thru' the block to keep the cylinder heads more even in temperature. It's an old NASCAR, roundy round trick.

Trouble is if you don't put some bypass water holes in the TStat, it will make the block overheat, not fiction, don't believe me try it and see.

I usually run 2 1/8" holes in my winter stat and 4 in the summer stat. Reasoning for this is it takes a real long time to warm up in the winter with 4 holes.

True, it does help to "burp" the air out.

There are some newer style stats with a notch in them and some that open in the direction of water flow, but not all.
johnny

 

hi johnny,
thanks for your tips/help mate!
so would you reccomend doing both the drill hole mod in the stat and block the coolent bypas hole in the block then johnny?
thanks
glen

 

I do this mod on all Gen I builds. I normally do the tap in the block, but it's easier to do on the water pump.
Take a 1/4" NPT and tap the water pump face where it bolts to the block, then take a 1/4" allen head plug and thread it into the pump so that it's flush with the pump face. If it's not flush, you'll end up with water leaks.

My 383 and 427 both have this mod.

The 383, 10.5 compression, runs the stock water pump, radiator and hoses for 89, I do have a 14" auxilliary fan on the condenser. It runs 180 all the time and 200-205 with AC on, summer, in traffic.
The 427, 11.5 compression, runs the stock water pump, radiator and hoses for 90, with the stock fans. It runs 180-190 all the time and 210-220 with AC on, summer, in traffic.

Both blocks have a half fill of hard block. Both have roller cams, and 236-242 @ .050 .570 lift, 242-248 @ .050 .615 lift.

Both have 180 stats. Temps run 2-3d F, at most, difference between heads. I've considered running coolant lines from the back of the intake to the front coolant runners on the intake, but haven't seen the need for it.

Both have external air-to-oil engine coolers on them, and the 89 has a air-to-oil cooler for the auto tranny with a 3500 stall. The tranny cooler on the 89 keeps the hot oil out of the radiator to help cooling, the 90 is a ZF.

I ramble, but the changes I've made keep coolant temps under control with stock radiators, imagine what they'd do with aftermarket radiators and water pumps.

Other engines I've built have no cooling problems, some of them have belt driven fans.
johnny

 

BTW (By The Way)
1/64" bit is around 1.5mm
1/8" bit is around a big 3mm
1" is 25.4mm
johnny