Drilling holes in head gaskets = more flow = lower temps: Change My Mind!

General engine tech -- Drag Racing to Circle Track

Moderator: Team

RW TECH
Guru
Guru
Posts: 2390
Joined: Thu Nov 24, 2005 9:08 pm
Location: DETROIT, MI

Re: Drilling holes in head gaskets = more flow = lower temps: Change My Mind!

Post by RW TECH »

NewbVetteGuy wrote: Fri Aug 05, 2022 6:51 pm
"Grumpy Jenkins showed that he had more smarts than a whole STACK of GM engineers!"

"The world of engineering achieved perfection with Grumpy Jenkins; it's only been downhill since then. Just think about how much further along internal combustion engines would be if he would've just lived forever."


Adam
No disrespect to Bill, but :roll:.

That statement was obviously formulated from reading enthusiast magazines. The other side of that is the dependency that guys like Bill actually had on OEM engineers and people in the same field as Bill who had more experience that Bill would call on occasionally.

Anyhow, don't drill gaskets. Just get the right ones to begin with.

Guys at home can't measure what actually needs to be measured, so they dink around with gasket holes, extra lines & hoses, etc. and trick themselves into believing it's better because the water temp gauge, usually probed from the water outlet area, shows a lower number. It does that because the cool water is "short circuited" from the trick mods & winds up flowing out through the area where the temp sensor/probe is, instead of flowing through the as-designed system & grabbing more heat from the cylinder heads on the way through.

Places with budgets, real test equipment, and talented, knowledgeable people are the ones who should goof with gasket holes & auxiliary plumbing. Pretty much nobody else should.
User avatar
Rick!
Expert
Expert
Posts: 531
Joined: Fri Jan 01, 2016 4:13 pm
Location:
Contact:

Re: Drilling holes in head gaskets = more flow = lower temps: Change My Mind!

Post by Rick! »

Cast iron heads on Vettes ended in 1986, according to a corvette forum. The '89 Vette I hot rodded had aluminum heads.
Reverse flow works when done right but as you all know, GM is about cost efficiency.
The "high stress" cooling test was typically a simulation of 10mph towing up a hill in first gear. Not sure 50mph in 2nd was any worse and with 50mph airflow, maybe not quite as severe. Low rpm, low vehicle speed, and a high ambient temp is combined with lean fueling where more fuel energy is transferred into the cooling system was where I found the toughest condition for a cooling system.
Coolant velocity in the heads needs to be balanced with flow; too high of velocity creates low static pressure pockets that promote localized boiling.
The SBC cooloant passages weren't originally developed with CFD but myriad t-couples and a dyno would eventually lead to the same result as CFD, albeit at a slower pace.
If GM created reverse flow cooling and produced it in 1991, which means they have prior art before then, a patent granted in 1993 is moot. The cows already left the barn. The article also doesn't state an NDA was signed by both parties. That is fundamental to prevent "stolen" IP. But, if Mr. Evans finds a favorable 9th Circuit judge, he will take home some cash. Polaris Industries can attest to that on an EFI system "copied" around the same era.
rgalajda
Pro
Pro
Posts: 385
Joined: Wed Apr 27, 2022 6:26 am
Location: Canada

Re: Drilling holes in head gaskets = more flow = lower temps: Change My Mind!

Post by rgalajda »

You can ask five guys in a room what temperature a an engine should run and probably get five different answers.
To begin with , most people don't even know a lot of temperature gauges aren't even accurate. They can be off by 10 %. That's 20 degrees at at 200 degrees Fahrenheit. Is the temperature gauge installed in the cylinder head or the intake manifold. Which cylinder head ?

In the 70's ,engines ran warmer because they reduced initial timing for emission reasons.

I had a machine shop tell me I was using the wrong head gasket for a BBC. This machine shop built circle track and drag race engines. When he showed me the head gasket to use I asked him if it was for a series flow block or a parallel flow block . He didn't know what I was talking about. He didn't know the difference. Did you know there are series flow and parallel flow mark 4 engines

I have seen an engine block come back from machine shop where the rear cylinders coolant area were still blocked with debris.

2 core , 3 core , 4 core radiators, crossflow vs down flow, tube sizes, aluminum rads.
Fan shrouds, fan to shroud spacing, Number of blades; Electric fans, sizing--do they need shrouds
Did you know in the 80's most rads changed to larger tubes to improve cooling. These performed better than the old 4 core rads.

The point is that there is a lot of basics overlooked when it comes to cooling.

I run a 454 BBC/500hp, parallel cooling, with a 2 core aluminum rad , factory 7 blade fan clutch . I can leave the car idling in traffic on a hot day without coming close to overheating.
There are a lot of ways to try to prove theories ( politicians )
RW TECH
Guru
Guru
Posts: 2390
Joined: Thu Nov 24, 2005 9:08 pm
Location: DETROIT, MI

Re: Drilling holes in head gaskets = more flow = lower temps: Change My Mind!

Post by RW TECH »

rgalajda wrote: Fri Aug 12, 2022 5:58 am
The point is that there is a lot of basics overlooked when it comes to cooling.
Exactly.
ChopperScott
HotPass
HotPass
Posts: 594
Joined: Tue Nov 30, 2021 8:47 am
Location: West Milford, NJ
Contact:

Re: Drilling holes in head gaskets = more flow = lower temps: Change My Mind!

Post by ChopperScott »

RW TECH wrote: Wed Aug 10, 2022 4:26 pm Guys at home can't measure what actually needs to be measured, so they dink around with gasket holes, extra lines & hoses, etc. and trick themselves into believing it's better...
#-o
'73 Camaro Z/28 NETO/N
434 SBC 11:1, 1.294, 6.178 @ 108.87, 9.81 @ 134.93 (3060#, Naturally Aspirated, Sunoco Ultra 94)
Chopper Air Port 917-589-1278
Warp Speed
Guru
Guru
Posts: 3279
Joined: Wed Jun 25, 2008 1:46 pm
Location: NC

Re: Drilling holes in head gaskets = more flow = lower temps: Change My Mind!

Post by Warp Speed »

NewbVetteGuy wrote: Fri Aug 05, 2022 6:51 pm
PackardV8 wrote: Fri Aug 05, 2022 6:36 pm Go for it!! What do those GM engineers know anyway.
"Grumpy Jenkins showed that he had more smarts than a whole STACK of GM engineers!"

"The world of engineering achieved perfection with Grumpy Jenkins; it's only been downhill since then. Just think about how much further along internal combustion engines would be if he would've just lived forever."


Adam
:lol:
BILL-C
Expert
Expert
Posts: 746
Joined: Thu Feb 07, 2008 9:57 pm
Location: Oakville, CT
Contact:

Re: Drilling holes in head gaskets = more flow = lower temps: Change My Mind!

Post by BILL-C »

rgalajda wrote: Fri Aug 12, 2022 5:58 am You can ask five guys in a room what temperature a an engine should run and probably get five different answers.
To begin with , most people don't even know a lot of temperature gauges aren't even accurate. They can be off by 10 %. That's 20 degrees at at 200 degrees Fahrenheit. Is the temperature gauge installed in the cylinder head or the intake manifold. Which cylinder head ?

In the 70's ,engines ran warmer because they reduced initial timing for emission reasons.

I had a machine shop tell me I was using the wrong head gasket for a BBC. This machine shop built circle track and drag race engines. When he showed me the head gasket to use I asked him if it was for a series flow block or a parallel flow block . He didn't know what I was talking about. He didn't know the difference. Did you know there are series flow and parallel flow mark 4 engines

I have seen an engine block come back from machine shop where the rear cylinders coolant area were still blocked with debris.

2 core , 3 core , 4 core radiators, crossflow vs down flow, tube sizes, aluminum rads.
Fan shrouds, fan to shroud spacing, Number of blades; Electric fans, sizing--do they need shrouds
Did you know in the 80's most rads changed to larger tubes to improve cooling. These performed better than the old 4 core rads.

The point is that there is a lot of basics overlooked when it comes to cooling.

I run a 454 BBC/500hp, parallel cooling, with a 2 core aluminum rad , factory 7 blade fan clutch . I can leave the car idling in traffic on a hot day without coming close to overheating.
There are a lot of ways to try to prove theories ( politicians )
Do you have any pics of serial flow vs parallel flow blocks i can see? I know that in very late 70's chevy added a couple of holes to deck of 454 blocks on exhaust side that fel pro says to drill on all earlier blocks. All of the race gaskets also have the extra holes. I've never heard of this called serial flow or parallel flow .
Carlquist Competition Engines
rgalajda
Pro
Pro
Posts: 385
Joined: Wed Apr 27, 2022 6:26 am
Location: Canada

Re: Drilling holes in head gaskets = more flow = lower temps: Change My Mind!

Post by rgalajda »

Parallel and Series flow gaskets
You do not have the required permissions to view the files attached to this post.
rgalajda
Pro
Pro
Posts: 385
Joined: Wed Apr 27, 2022 6:26 am
Location: Canada

Re: Drilling holes in head gaskets = more flow = lower temps: Change My Mind!

Post by rgalajda »

Info
You do not have the required permissions to view the files attached to this post.
rgalajda
Pro
Pro
Posts: 385
Joined: Wed Apr 27, 2022 6:26 am
Location: Canada

Re: Drilling holes in head gaskets = more flow = lower temps: Change My Mind!

Post by rgalajda »

pics
You do not have the required permissions to view the files attached to this post.
User avatar
FC-Pilot
HotPass
HotPass
Posts: 913
Joined: Tue Mar 17, 2009 2:23 pm
Location: Springtown, TX
Contact:

Re: Drilling holes in head gaskets = more flow = lower temps: Change My Mind!

Post by FC-Pilot »

RW TECH wrote: Wed Aug 10, 2022 4:26 pm
NewbVetteGuy wrote: Fri Aug 05, 2022 6:51 pm
"Grumpy Jenkins showed that he had more smarts than a whole STACK of GM engineers!"

"The world of engineering achieved perfection with Grumpy Jenkins; it's only been downhill since then. Just think about how much further along internal combustion engines would be if he would've just lived forever."


Adam
No disrespect to Bill, but :roll:.

That statement was obviously formulated from reading enthusiast magazines. The other side of that is the dependency that guys like Bill actually had on OEM engineers and people in the same field as Bill who had more experience that Bill would call on occasionally.

Anyhow, don't drill gaskets. Just get the right ones to begin with.

Guys at home can't measure what actually needs to be measured, so they dink around with gasket holes, extra lines & hoses, etc. and trick themselves into believing it's better because the water temp gauge, usually probed from the water outlet area, shows a lower number. It does that because the cool water is "short circuited" from the trick mods & winds up flowing out through the area where the temp sensor/probe is, instead of flowing through the as-designed system & grabbing more heat from the cylinder heads on the way through.

Places with budgets, real test equipment, and talented, knowledgeable people are the ones who should goof with gasket holes & auxiliary plumbing. Pretty much nobody else should.
Coming from the vehicle testing world I have to agree fully with this statement. All our backyard building can not fully equal all the testing done by the OEM’s. Yes, they have to reduce costs, but I promise you they know in detail what is going on through the whole cooling system. I don’t second guess their stuff.

Paul
"It's a fine line between clever and stupid." David St. Hubbins
gunt
Expert
Expert
Posts: 521
Joined: Sun Sep 26, 2010 2:52 pm
Location:

Re: Drilling holes in head gaskets = more flow = lower temps: Change My Mind!

Post by gunt »

my view , any small tiny holes are only there to aid bleeding areas of the coolant system , not intended to flow anything of great importance
NewbVetteGuy
Expert
Expert
Posts: 779
Joined: Sun Aug 07, 2016 4:11 pm
Location:

Re: Drilling holes in head gaskets = more flow = lower temps: Change My Mind!

Post by NewbVetteGuy »

PackardV8 wrote: Wed Aug 10, 2022 12:00 pm
NewbVetteGuy wrote: Wed Aug 10, 2022 11:54 amReverse coolant makes no sense unless you have a good and simple way to avoid any steam pockets (maybe low coolant temps and high pressures from a good pump are "good enough" mitigation). Adam
Yes, No, Maybe. All we know for certain is of all the fixes available to them, GM engineers chose reverse flow cooling as the best solution.
And then they later ran away from it, never to go back to it again, though. Right?


Adam
NewbVetteGuy
Expert
Expert
Posts: 779
Joined: Sun Aug 07, 2016 4:11 pm
Location:

Re: Drilling holes in head gaskets = more flow = lower temps: Change My Mind!

Post by NewbVetteGuy »

RW TECH wrote: Wed Aug 10, 2022 4:26 pm
NewbVetteGuy wrote: Fri Aug 05, 2022 6:51 pm
"Grumpy Jenkins showed that he had more smarts than a whole STACK of GM engineers!"

"The world of engineering achieved perfection with Grumpy Jenkins; it's only been downhill since then. Just think about how much further along internal combustion engines would be if he would've just lived forever."


Adam
Guys at home can't measure what actually needs to be measured, so they dink around with gasket holes, extra lines & hoses, etc. and trick themselves into believing it's better because the water temp gauge, usually probed from the water outlet area, shows a lower number. It does that because the cool water is "short circuited" from the trick mods & winds up flowing out through the area where the temp sensor/probe is, instead of flowing through the as-designed system & grabbing more heat from the cylinder heads on the way through.

Places with budgets, real test equipment, and talented, knowledgeable people are the ones who should goof with gasket holes & auxiliary plumbing. Pretty much nobody else should.

Agreed. Awesome response.

If the goal is lower cylinder head temps, and more even cylinder head temps, measuring around the intake outlet could be misleading. -A great example is that stock early GEN1 SBC water pump bypass hole that goes up to the front of cylinder #2 and then likely straight to the thermostat instead of sending it through the whole engine and heads to improve cooling. (I have to think that coolant temps going out of the engine would at least be a tiny bit hotter with the coolant bypass hole plugged.)

Adam
Walter R. Malik
Guru
Guru
Posts: 6355
Joined: Tue Jul 24, 2012 11:15 am
Location: Roseville, Michigan (just north of Detroit)
Contact:

Re: Drilling holes in head gaskets = more flow = lower temps: Change My Mind!

Post by Walter R. Malik »

NewbVetteGuy wrote: Fri Aug 19, 2022 3:08 pm
If the goal is lower cylinder head temps, and more even cylinder head temps, measuring around the intake outlet could be misleading. -A great example is that stock early GEN1 SBC water pump bypass hole that goes up to the front of cylinder #2 and then likely straight to the thermostat instead of sending it through the whole engine and heads to improve cooling. (I have to think that coolant temps going out of the engine would at least be a tiny bit hotter with the coolant bypass hole plugged.)

Adam
That hole you mention will flow coolant from the passenger side cylinder head back to the water pump inlet; exactly the opposite direction of what you just claimed.

THAT coolant has already been through that side of the engine.
http://www.rmcompetition.com
Specialty engine building at its finest.
Post Reply