602 cooling lines question.

[DaveBauerSS6]

Helping a friend and both new to crates, bought used 602 and didn't have the bypass hose at the front of intake to water pump.
What's it for?
Will it work on the top of the pump; the side inlet is covered by the alternator?

[rubbinsracin]

I'm not sure I'm understanding what you are talking about exactly, but if you are talking about the two holes in the front top part of the intake, that is where people put water temp, pressure, dummy lights, that kinda stuff.

[brad hibbard]

there is no provision for installing water lines on a 602

like the last poster said the 2 ports on the front are for temperature senders

there are none in the back of a 602 for circulating the hot water from the heads

the two in the middle should NOT be used for racing purposes----they are to heat the air/fuel mixture on a street car in cold weather------we actually want to cool that area, I usually leave that passage open to air it helps to prevent carb boiling and vapor lock

Brad

[DaveBauerSS6]

The port is on the drivers side between the head and the thermo housing. Its a 3/8 pipe plug with a hole about 3/16 to 1/4 size behind it to the water jacket. You can see the port thru the thermo mount. Several guys that have bought new 602s say it is in the info that comes with the motor. We are looking for a copy. GM recommends it be plumbed to the lower hose area of the water pump?
Sorry about the vagueness of the question.
Thanks for any help.

[brad hibbard]

are you talking about the very front of the intake?----not top but front

[DaveBauerSS6]

are you talking about the very front of the intake?----not top but front

Yes, the hole faces forward.

[brad hibbard]

OK---now I know what you are talking about

that hole is in both 602 and 604 intakes and we have never used it in either---we simply plug it with a 3/8 pipe plug

I will try to find an information pack that is sent with a 602 engine and read closer than I have because i don't remember reading anything about that

If you find some actual lterature about plumbing it please post it so we can all learn from it

Brad

[DaveBauerSS6]

OK---now I know what you are talking about

that hole is in both 602 and 604 intakes and we have never used it in either---we simply plug it with a 3/8 pipe plug

I will try to find an information pack that is sent with a 602 engine and read closer than I have because i don't remember reading anything about that

If you find some actual lterature about plumbing it please post it so we can all learn from it

Brad

OK working on it.

[JAMESGANGRACING]

Brad, you say you just remove the 2 center plugs and leave them open?

[DaveBauerSS6]

Have the manual that comes with a 602 purchase.

Quote.
Title: CT350 Circle Track Engine 19258602- specifications
Rev 19ja10
Part # 8896057
Page 2 of 33
Cylinder heads: Last paragraph - Any small block engine, regardless of year , that uses Vortec heads, will require an external coolant bypass line from the intake manifold to the 5/8" hose nipple on the water pump (passenger side). Suggested routing is from the 3/8 NPSF boss on intake manifold to the water pump.
End Quote.


Some guys read this and have the bypass and others don't. Will call GM hot line Tuesday and question the purpose and the placement.

[sj valley dave]

Hey Dave, are you helping out a LLM or a Sport Mod with the 602? Who's car? Hope to see you guys next week...Going to try and get the DLM down to Bako, unless Johnny's wife has different plans for his Birthday next Saturday...LOL

[brad hibbard]

Brad, you say you just remove the 2 center plugs and leave them open?

yep----anything to cool that area of the intake will help HP

[DaveBauerSS6]

The question was from Loren DeArmond, IMCA Northern Sport Mod. But since we started talking there is more questions on why and where. Some motors are on 40 plus nites without the bypass and running fine?? Not questioning GM , just want to understand.
Might come watch, been busy at work and 2 motors to finish.

[DaveBauerSS6]

GM Tech Hotline 866-453-4123 Press 2 then 4 for performance tech.

The bypass is to release air from the block to the intake via the thermostat passage. The air is trapped by the Vortec head design. In order for this to work the water pump you run must have the passage drilled just below the pass side lower water pump bolt. A lot of the cheap pumps have this blocked. Recommended port on the pump is the side next to the lower rad hose, but he said the top port on the pump would work.
Hope this helps, the tech line was great, no waiting. They also give you a case # and the followup call goes quick.

[DaveBauerSS6]

Those are both top end companies that know cooling. It would be a good question for them also.

[rubbinsracin]

Never seen a crate motor plumbed like that at our track. What kind of power difference are we talking brad?

[brad hibbard]

Never seen a crate motor plumbed like that at our track. What kind of power difference are we talking brad?

this whole topic has made me think a bit-----just adding a water line or bypass is not going to add power but in some cases will even out temperatures to where timing or fuel curves can be changed to be a benefit

I don't think this simple bypass will be significant enough to be able to adjust timing but it might help with some cooling issues

I can't believe I have missed that in the manual but will seriously look into the effects and benefits

thanks for starting this topic ---its things like this that help us all get a little bit better.

Brad
www.race-1.com

[DaveBauerSS6]

The GM tech said it was to release air trapped by the design of the heads. Not sure if there is a performance improvement.
Will try JR Motorsports on their thoughts.

[DaveBauerSS6]

JR feedback: Talked to two guys, one didn't know and refereed me to another that said they don't see a need for it. Not much depth in the answer???

[dynoman14]

Dave Bauer,
Sounds like you got some great feedback from a lot of experts on here but after reading 2 pages of BS humming and hawing around the question....

Here is the answer to your original question;

On most water pumps the top hole is an inlet designed to be used from a purge / surge container for overflow recirculation or so you can run a high pressure water system. In that case you will have to purchase a water pump capable of pumping water at high pressures ( 25-50psi ) and weld your radiator outlet closed or shim up a cap to whatever PSI you want it to pop to the purge/surge container, at that point instead of blowing coolant all over the track you simply suck it back in the top of the water pump, going on to live another day, saving your engine and not wrecking 1/2 the field wrecking in your own spillage.

If you need to learn about the system aeroquip has had a schematic of the deal in their catalog for about 10 years now. Not sure about the web-site.

If you pick up physics book, or look on the internet you can calculate the temperature at which water boils with a simple formula. At high pressure it is a lot more than 212F*. If you are smart enough to pursue this further you might even find some information about detergent salts that can raise the boiling point of water another 50-100* so with pressure and some additives you can really run hot without blowing up.

There is a real life warning, failure to heed the excess pressure of such a system will result in death and it happened to a NASCAR teams crew member when he tapped a water re-fill can into the high pressure side of the system instead of the low pressure side. 99.9% of the racing world would never see this as you would not have a Live / active re-fill system on your cars.

So with that said, Chevy engines have always had a problem with water boilling between the cylinders and guess what they are the lowest pressure areas in the engine so that is why you have to use extra pressure to get rid of that. I know people will say the temp gauge is only reading 200 but the water between the two middle cylinders is more like 100* hotter, if you like you can mount a sending unit there and find out what it is. Trust me, it is.

To resolve this issue about 20-25 years ago I started running lines off the sides of the water pump to the center of the cylinder heads either on the intake side or the exhaust side, whichever is easier. In the case of a crate engine you are not supposed to drill and tap and all of that mumbo jumbo so all you have to do is be a little smarter than the piece you are working on and put a -6 or -8 fitting in the side block drains and run pressurized water into those locations off both sides of the water pump. Now if you spend more than $49 on a water pump you might see that racing water pumps come with pre-tapped fittings / flanges on the top and on each side of the water pump. They are there for a specific reason, and Edelbrock, Stewart and Adams did not put them there just cause they had extra time and needed holes to drill and tap...

And that my genius friends is how you cool a crate engine down enough to run an electric fan and save 26RWHP @ 6500 and 42RWHP@7500rpm's of drag off that antique 4 bladed steel piece of crap I see running on 99% of the crate cars I see.

If you don't believe it why do you think (not a nice word)(not a nice word)(not a nice word)(not a nice word)ie Coleman invented a fan blade by-pass for qualifying. Oops hope I didn't offend any of you by name dropping cause I know it gets folks all hot and bothered. I did some of the testing for him 15 years ago on my 2-BBL late models.

Maybe working on that a while will shut up all of the experts who have been telling me for the last couple years that dirt engines can't run electric fans, BLA,BLA,BLA. You might want to take a closer look at some of the Fast Supers in your area and see who is running electric fans, it is more like 40-50RWHP on one of those engines.

If I can get my old and 1/2 blind webmaster off his butt I'll see if he can post some pictures for me.

Stick around another couple of years and I might disclose how you can run 200psi oil pressure with a 50psi pump and still have the gauge read 50psi, yet another simple physics problem to overcome and all you experts say you cant turn a crate 7500rpms...pick up a fluid transfer or fluid dynamics book and read a little and pay special attention to the chapter on differential pressures, if it ain't got a chapter on that you don't have the right book.

Yea c'mon