this isnt necessarily efi content but i figured this would get more answers & comments here since some of us are a little more **** about performance

I bought a beater, long story short, it has a weiand aluminum waterpump which supposedly flows more and are lighter than the cast iron one on my 'bird. I was thinking about reasons for swapping it over to my 'bird..
Right now the cooling system on my bird is far from optimized, probably more like just enough to keep it from over heating.

I at first wondered if the alum. pump would free up some hp and then it occurred to me the cooling system is far more involved than just freeing up hp and here are some ideas I had about optimizing my system that Id like some input on

First off, id like to add that pump, not because it frees up hp per se, but because i theorized it would increase in block + head coolant pressure
I wondered if this would have a similar effect as all those tapped tubes in the water jacket of race cars cyl heads to minimize steam pockets and temp irregularies which play havoc on combustion

Am I on the right track?

It also occurred to me that running a greater percentage of antifreeze/coolant would also aid in this area since it has less a tendency to boil thus preventing steam pockets, thus preventing temp irregularities in the combustion space, creating a "softer" area for the whole bang thing to happen.

Does this make sense? or would it just be counter productive since coolant doesnt absorb/release heat in the radiator as well as water? I guess it would make sense for a strip application for a thicker coolant mixture but perhaps not so much for the street. I would also hazzard a guess that this setup if it did provide for a better more uniform coolant temperature would decrease octane sensitivity. Right now im running a 40/30/30 mix of 40% water, 30% coolant, 30% rust (heheh jk... more like 10% )
any thoughts?

also, I understand that a 180 degree block and head temp is probably best for performance, and its up to the job of the thermostat to maintain this (although i currently have a 160 stat) say, a 160 stat, prevents or delays overheating in my application because its not letting the fluid in the block load up with too much heat before it hits the radiator where some of that heat will be released into the air and some will stay and return back to the block,
Would this simply mean that the radiator, and airflow over the radiator are just not up to task? I take it that if the car isnt maintaining the thermostat temp it is because the heat isnt being released as it should somewhere else in the system (boy it helps to write things down you end up answering your own questions, duh)

so i guess the main question pertains to cooling system pressure in the block and mixture composition

any thoughts would be appreciated

ps, i know plugs play a part in this too and yes im running too hot of a plug but that will be corrected shortly

[This message has been edited by Pablo (edited November 12, 2000).]

 

This is sure to raise some controversy. Check out http://www.evanscooling.com/ and their NPG coolant.

------------------

 

Pablo, Running a smaller percentage of coolant in your mixture will help cooling imensely(sp?). Since you live in Fla I would reccomend 80/20 mixture. this will keep it from freezzing down to about 20* F. Also being that it is mostly water the heat will exchange faster as it goes through the radiator, which is also another advantage of having a high flow pump. I don't believe that the pressure of the coolant in the block will help you out much, if any at all.

I have a 160* t-stat and this summer my car never got over 180* unless I forgot to turn on the fan. i hit 180* while was idling in traffic in the sun for about 30 mins. also it cooled the engine down extremely fast. i could go from 220 to 160 in about 5 mins. It was raeally nice. I never had the A/C running though.

Hope this helps you out a little bit.

Later,
Lars

 

There is just too much nonsense out there about thermostats and operating temps.
I have a 190 in the GN, and running really really well with that. I turn the fan on at 195 and off at 190.
If there is something that should be real sensitve to detonation 18 PSI should be it.
TPS 3.8v
255 HP
393 Ft/lbs
@ 3.400 RPM
granted data logged calculated numbers,but those are some serious numbers for a 231.

Using a 160 on some applications disables the EGR.
Using a 160 can richen the mixture
Using a 160 can change the timing bias
all differ by application.
BUT, All this stuff can be done in the chip.
In back to back testin I found NO difference in performance when the calibration was optimized for CTS. DID 160-180-195s back to back. Full 1/4 passes at a NHRA track.
Folks back in 50s (when this was first popular) thought just burning more fuel with more timing made more HP. Sorry that is old tech and about flatheads.

BTW, I have incresed the cylinder head and block pressures as you mention, and looking to increase it even more.......

Thermostat just sets min operating temp.
Just for grins ran the GN at 225 for a while, picked up 2d knock.

WHAT you need to do it watch the oil temp.
CT has slot to do with oil temp, and you only 220-240 oil temps
Sorry if this looks like a rant, just I've put alot of time into this stuff.
Also, revisited the 8D mask still done't see anything useing IAT other then EGR. Nother wife's tale about moving it for performance. Disable EGR do to IAT and get some result.

 

ah ok, so i take it, that the over all coolant temp isnt so critical for performance (judging from what you said about no difference from 160-180-195) as is a uniform temp and oil temp is in the vicinity of 220-240 degrees

as for increasing the cyl head and block pressure, did you simply use a higher pressure rated cap? Im using a parts store 16 lb unit which of course is probably less than that in actuality and wondered if it would be a good upgrade to go to an 18lb unit.. or is any more streetable for a stock radiator etc?


as for the IAT, and EGR, both are not an issue since im running the 7747 and a non egr manifold

thanks

 

btw, at 3.8v im guessing you arent even at wot unless the gn setup is different.. is that on purpose?

 

Was a quick run, but not WOT.
In the current config., the car has been running for about 3 months now, and just now starting to look at WOT seriously.
This is what I mean about tuning, just starting slowly and doing a work around finding what the engine wants.

 

You will get more consistent performance at the higher operating temp.
Changing caps while it changes the system MAX pressure doesn't really effect the heads operating pressures. That is a function of pump design rpm, and thermostat opening area.
On the 3rd Gens (least on the 84 LG4s), the heater is always on and there is the bypass that need looked. The bypass is that extra hole on the passenger side of the waterpump.
I normally rude that to a 1/8" and restrict the heater to a 5/16" hole.
This is done with testing to get the pressure it highest, and hot have the operating temp increase too much at sustained WOT

 

thanks grumpy,

I've allready eliminated the heater on my car so I guess the only thing left is the high flow pump and maybe some testing with various thermostats

I too have witnessed less consistent performance at cooler engine temps

 

When ya do the water pump tap the *extra* hole 1/8 pipe and drill a 1/8" hole in it.
Will help with less bypass

BTW
Grumpy Jenkins in his SBC book kinda covers things in depth.
Like filling the bypass hole in the block

 

interesting I wasnt aware of bypass holes, thanks for the info


Im not familiar with this "extra" hole, is this on the water pump or on the block? and im supposed to tap it with a 1/8 tap and put a 1/8 pipe with a 1/8 hole? sorry ive just never seen this before so its not real clear

thanks for the book recomendation ill pick that up when i get smokey yunicks book which i was planning on

 

Passenger side where the water pump passage is there is a second smaller one, I do the block so I can change pumps in a parking lot and not worry about it.
1/8" pipe plug (allen) with a 1/8" hole in it

 

I appreciate the information Bruce, I'll do that

 

in my quest to build a more effective cooling system ive run into a bit of a snag thats somewhat perplexed me

i posted on the general tech board but i was hoping one of us prom guys could help me out what with the knowledge here
https://www.thirdgen.org/messgboard/...ML/003365.html


summary: temp gauge sender is in non stock location, passenger side rear cyl head

when thermostat is closed the sender goes off the chart, like some pretty heavy duty localized over heating. Since i put the restrictor in the block and drilled the T stat, it seems to have delayed what is going on (it would happen quickly and go away just as quickly before what with my anemic single fan) the car would maintain a temp above that of the thermostat rated temp

ive since installed dual fans quite capable of bringing temps down UNDER the thermostat rated temp and the situation has been exacerbated it seems.. while the temp rise is delayed, it no longer goes back down because the thermostat doesnt seem to be opening or staying open anyways for any length of time

first off, does the passenger side rear of the cyl head usually get a hot pocket? am i just seeing what gm didnt want me to see since i installed the temp gauge sender there rather than the front driverside

if that is so.. then it seems to me the best course of action is to completely plug the bypass hole for the water pump, and run a tube from the hole where the sender is back up to the thermostat housing (utilizing a housing with the sensor ports)


any thoughts?


Ive been afraid to even mess with the car tuning wise (dont wanna blow a head gasket) now that the problem got worse (because of the dual fans, higher temp stat etc)
I know i need a fan switch but i dont think it should be doing this either way

thanks, and i added more details in the post i linked

Pablo

 

The sensor needs to be around the thermostat area, you want to know the average temp., the in the head idea is bad because one side can be over heating and you'll never see it, till your out of aqua. If you blocked the pump bypass hole then you'll need at least 4 (5/32") holes in the thermostat to bypass a similiar amount of water. Which is still a ton, better IMO then the stock way where att that water bypasses the radiator. Therir way is a compromise for warm-up and by passing. In compromises someone loses

 

Well the stock location is on the cyl head aswell just at the front of the drivers side head

are you saying that this overheating at the back of the head on the passenger side is normal for example? its flying off the gauge past 260 when the thermostat is closed, and yes, the average temp.. or the temp flowing through the holes in the T stat is much less than that one hotspot at the back of the head

do you suggest completely blocking the bypass hole and drilling the holes in the T stat to remedy this situation? what about a tube from the sensor location as it is now back to the T stat housing ?

this really worries me, is it something to worry about or normal?

 

The hot spots on chevrolet small block heads is between the two siameased exhaust ports. The port You have your sending unit in is the one two fan tpi cars used to turn on the second fan when temp got above 240. If you are getting around 260 there, something is wrong. Are you sure your temp monitoring device is a good one? As for a thermostat use a robertshaw poppet type, They flow much better than a standard type.Drilling three 1/8" holes on the outside will help also. I run A stewart level 2 pump and poppet type thermo and a 21 psi cap. With pure water and prestone rust agent(untill it gets cold).

------------------
87z 383,afr 190's, crane hyd roller(224/230-.509/.528,112 sep),Ported and polished mini ram, 30lb inj, 3.42 gears, strange 12 bolt, tremec 5spd, , 1,3/4" slp headers.

 

The worst hot spot is the area closet to the the center exhuasts true, but you can easily flash any coolant to steam around any of the exhuast guide seat areas. (When improperly tuned).

 

Over the years and in several types of engines, I've found anywhere other then by the thermostat is way less then accurate. Remember to, that the sender is effected by the surrounding metal. It takes a large heat isolator to even remove the heat sens'd with a MAT, on the intake.
The coolant doesn't all go to the rear of the block before rising, part of the oem problems are the large core plug openings. Folks claim the reason pipe tapping them and them resurfacing the block is good is cause of the extra area, I say part of it the redirection of the coolant.
the cooling system is a whole lot more complex then folks give it credit for.
coolant is just as important as oil
both deserve lots of attention

 

Why not drill & tap the intake man. at the rear where it lines up with the coolent openings in the cyl. heads and run lines to the T-stat housing. Just a thought.

-Auggie-

 

I thought of that auggie, but upon inspection that would be a bit of a task because my intake has some reinforcement risers cast in right there so id have to machine those off and then do the holes

i do think that would probably ideal that would definatly promote crossflow


I think im gonna end up blocking the bypass hole completely, leaving the stat with just3 1/8 holes and running a tube from the rear of the head to the T stat housing.

The only thing im worried about is that the driverside isnt getting the same flow the passenger side is althought im unsure of whether or not that side is getting that hot (i have a CHT gauge and it doesnt read that high its on the #7 cyl)

 

If your running a TBI manifold, and proper gaskets, what I did was epoxy some thin Brass over the rear coolant coolant circulation holes to reduce the coolant that by passed the head, by redrilling them to .080".
The TBI manifold is fairly clever.
Some items of note, on the LG4s the heater is always on.
On the TBI manifolds when the heater is on it seriously alters how things are heated. In an application with out the inline heater valve, the *hot* coolant from by the thermostat also *splits* and in part flows under the manifold when the heater is on. So there is a Driver controlled manifold heater.
On one car, made a .75" spacer the same pattern as a thermostat gasket. Then drilled and tapped a hole for a 3/8" pipe fitting. Then used a 5/8" hose to 3/8" pipe fitting, then ran the heater off of the water by the thermostat rather then using the heater to circulate more coolant thru the manifold. Had to have a recess in the AL piece for the thermostat.

 

unfortunately (or fortunately ) im not running the tbi manifold, its an edelbrock torker II single plane with the tbi on top...

i tried just completely blocking the bypass and drilling the larger holes in the t stat but it did nothing so i bought the water neck with the two ports and got some compression fittings and brass pipe im gonna attempt to run it from the sensor hole in the head and put the temp sensor in the t stat housing
hopefully these fittings and whatnot dont leak (they hold 30 some odd psi of house water pressure right?) anyways

im also getting a fan switch, unfortunately none of the ones the parts store has are near 180 the lowest are like 194 on 174 off i would think that would mean my car would be bouncing between 194 and 180 all the time but its probably better than having them on all the time

i hope i can defeat this little problem once and for all

 

My question is, why would your engine be different than any other sbc out there?

I never heard of any one running water from the fan switch hole to the tstat housing. You might end up bypassing coolant that's needed somewhere else. The other bank won't be getting the same plumbing so how can cooling be uniform?

I think you are gonna complicate your problem by adding that bypass piping.

There has to be an easy solution to this.

What does it do with no tstat installed?

[This message has been edited by Brent (edited December 08, 2000).]

 

I havent tried that brent but im pretty sure it wont do it since it only does it when the t stat is closed

 

This just in.
Spent the day foolin around with Temp sensors and fan switches and locations.
The only way we were able to get them to jive was mounting them all near the thermostat, wound up drilling and tapping holes in the manifold to do this.
Had a SW, Cyberdyne (?), GM fan switch, and compared everything to the ECM and CTS.
Some ecms use two different pull up resistors and on this one seems like there is a little oddity to readings right at 65-70dC.
The ecm temp sensor is HEAVILY dampened and slow to change.
For a normal manifold I wouldn't be rerouting things. Just opinion here.
I'd either just use the whole oem set up or plug/restrict the bypass, and drill the thermostat.
Mounting any senders in the thermostat housing, or even in the head I would refrain from. If it takes tapping the manifold to get the senders by the thermostat that's what I'd do.

 

Thats what I will do then. The more i think about it the more i think the little 'oddity' you mentioned is occurring i might just replace the sender while im at it. It just defies logic that the temp gauge can read beyond 260 degrees for several minutes at a time im talking like 5 -10 minutes with no sign of ping, and CHT temps looking normal (allbeit on the other head but a similar location)

Sometimes I over think things thinking the most complex situation is whats happening neglecting to just look at the simple stuff.. actually it happens alot