tempature smallblock chevy

[Tolle]

Hi all, I have a couple of problems with my newer sbc. crate engine, under 3000 miles. Its in a steel 30 ford roadster, 2900 lbs.edelbrock intake and carb, 2102+1405, block huggers , walker alum. radiator , 700r4 trans with a jag 3.06 rearend . Thing is it runs too cold , drove to a meet 800 miles , and it never got over 160 f. and gas milage is lousy,I was certain I had a 160f. thermostat in it , but when taken apart it was a 195f. that was not working.So I got a new one checked for function and replaced it . But now it ran cooler ? So today I blocked off the entire front of the radiator and gave it a spin, came right up close to 195f. and stayed there.Should I be thinking about some sort of restrictor in a hose or do you have any other suggestions . The other issue is gas milage , I know a cold running engine will not give you gas milage , but I`m getting 14.1 mpg. Cruising at 1500 rpm. = 54 miles and hardly ever go above 2500 rpm. Any thoughts would be appreciated  ( the water pump is a no name alum. deal) Thanks

[Learpilot]

I have a 36 Dodge weighs 3100# SBC 700r4 with 3.55 gear, walker brass radiator. My engine would run 160 with a 180 thermostat. I put a 195 balanced thermonstat and now it runs 190 with the a/c on. Look up balanced thermostat on google. I got mine at Autozone for $11.95.
About gas mileage, I had a 3.00 rear end and I also got 12 to 14 mpg on the highway. I changed thr rear end to 3.55 and gas milage went up to a high of 23 mpg. I have EFI and that is some of the mileage, but if you don't have enough rpm the carb will be too rich. My rpm at 65 mph is 2000 rpm.
I hope this helps.
Rick

[wayne petty]

good advice above..


let me give you the theory...

the thermostat blocks the coolant flow into the radiator... forces it through the bypass circuit and back through the block and heads again... past the closed thermostat.. until the heat is built up enough to open the stat so the coolant in the radiator can be swapped  with the hot coolant in the engine...

when the cooler coolant circulates in.. it closes the stat... so the coolant in the motor circulates and picks up heat again...

the stopped coolant in the radiator is cooled by the ram air.. and the radiator cooling fans...


with you having problems...   i want to know...    how is your bypass system hooked up.....

the heater hoses ...

when the thermostat is closed.. there is additional pressure build up behind it to push the warm coolant through the heater hoses.. the long way through..

i have found a few systems set up..  where the heater hoses dump coolant into the radiator..    the cooling fans then cool it... so the engine almost never gets to normal operating temps...



so...  how about a picture of your engine and various cooling system hoses...

ask a few  questions... i look in daily...

[Mikej]

How many bleed holes does your thermostat have? Some of the performance ones have  4 . If yours does and you have a good radiator it may not get up to temp.

[Tolle]

Hi again, I replied at lenght yesterday even with a picture, it somehow got lost? so thanks for the response.First off I looked up the balanced stat,called 3 different parts shops and none had ever heard about a balanced thermostat.About the gas milage you suggest more revs,could I as a test, drive it DA instead of OD that would give me more revs, but would it damage the transmission?
Wayne:the cooling system consists of the lower hose,upper hose,thermostat with housing and the radiator. no other hoses.
Mikej: I don`ta know about bleed holes , but it is a standard Stant thermostat.
My own thoughts are mabye the pressure from the pump is holding the thermostat open, If I can`ta get hold of a balanced stat. mabye I could run a bypass from the heater holes on the pump?
Regarding gas mileage would it help to lean down the carb 2 steps?

[wayne petty]

a few more questions...

where is the temp sending unit.   intake manifold next to the thermostat... or in the thermostat housing above the thermostat.. or side of the cylinder head...


chances of the water pump holding the thermostat open against its big spring...  not much....

have you verified the actual intake water passage temp and cylinder head temps with an infrared temp gun??

does your intake manifold and water pump have threaded but plugged passages to install a bypass...  i am not telling you to... your engine is probably clean enough to eat off of... and polished to the hilt...


a bypass circuit will let the coolant in the engine circulate until it comes up to the operating temp.. then open just slightly to exchange the coolant with the radiator until the cooler coolant reaches the thermostat and it closes it.. allowing the coolant in the engine to come back to temp.. this usually stabilizes the engine temps...

i am only trying to help you figure out this odd situation...  

i have one last cooling system question...  how many gallons does it take to fill it...  

perhaps the radiator is of a large enough size... that when the coolant swaps...  its has totally cold coolant as the radiator is big enough to cool it... so you might end up with restrictors over the radiator like big rigs have during winter months...  or put a shroud on the inside that might restrict the air flow through it..



~~~~~~~~~~~~~~~~~~~~~~~~~

now on the fuel mileage...

at 1500 rpms with a carb... you are running on the idle circuits and the idle transition circuits...    probably not enough air flow to run fully  on the mains circuits...  so you fuel mileage may suffer... so you may be working the throttle excessively to drive.. this works the accelerator pump and reduces fuel economy also..

getting the engine to run up on the mains circuits will let the carb run the way it was designed...

port fuel injected motors can run well at low Rpms.. as they spray fuel in.. they do not have to use the speed of the air to pull it over...

do you happen to have one of the 8007 390 cfm holleys laying around.  they are much smaller and might be able to increase your fuel economy...

or even throwing a quadrajet back on it...  as the primarys are small and designed to operate at lower air flows....

and... does your exhaust system have a oxygen sensor port... so you could toss on a oxygen sensor and a 30 buck air fuel ratio gauge... even as a temporary install.... while tuning the carb...

just ideas.....

wayne


oh... and for the posts that get lost... long posts need to be previewed... this sometimes helps to keep the server from timing you out.. i used to loose a few...

[Learpilot]

a few more questions...

Mr Petty has a lot of great ideas.  I first found the balanced thermostat from a friend that races dirt track and was having cooling problems.   Another racer let him borrow a balanced thermonstat and it cured his overheating problems. It is just a more precise thermostat.
Running a too rich carb will make engine run cold as well as bad gas mileage. Try a gas mileage run in drive and see if your mileage increases if it does you need a lower gear, like 3.55 to 3.70. If you can cruise at a higher speed, that may give you better gas mileage. You need about 1800 to 2000 rpm at cruise.
Street Rods are like Race cars we never get them to do everything just right, but we never quit trying. That is what makes them FUN !
Rick

[wayne petty]

http://www.flowkoolerwaterpumps.com/info/thermostat_overview.shtml



http://www.stewartcomponents.net/Merchant2/merchant.mvc?Screen=CTGY&Category_Code=Therm

above link, you can see the vent hole they drill in them to allow some coolant to circulate through....

found this on google also..

http://www.roddingroundtable.com/forums/viewtopic.php?p=107129

seems familiar



http://www.summitracing.com/search/brand/Milodon/Product-Line/Milodon-High-Flow-Thermostats/?autoview=SKU


i like these thermostats...  but most of the time... i just end up with a conventional thermostat..

i think that pepboys sells these robert shaw thermostats...  but i rarely go in.. the hollywood store is only 3 blocks away...  i just don't live being followed around in the store...  the only time i cannot find someone is when i am standing at the parts counter.. then they all vanish...   perhaps... i will venture out tomorrow...  drop one in the mail...  i wonder... how many forms i will have to fill out..

you can drill your own holes if you want...

3/16 is like 5 MM... or.. something like that...


post some pictures....


perhaps... the car is just so cool... it will never run hot...

[Crosley.In.AZ]

Bolt the  SBC  engine into a 48 Anglia with a full hood on the car.. it will heat up.



How is that old phrase on Ford flat head engine?  

If your flat head does not run very warm to hot... your temp gauge is broken

[chimp koose]

A/F ratio meters can be "fooled " into reading a lean condition with late ignition timing. Late timing can also cause low vacuum which can keep you in the idle/off idle circuits longer. Late timing can also make an engine run slightly cooler as you are kicking more heat out the tailpipe. 'Factory' timing setting may not be ideal for your car as it probably weighs considerably less than the donor vehicle. I would suggest you play with your ignition advance until you find where your car is most responsive,then play with jetting the carb. Others have made a good point that if the car does not get into the main metering circuit ,fuel mixture quality as well as metering will be less than ideal. Why not try a shorter set of tires as a test of the gear ratio idea. If you go to a site wallaceracing.com you will find a bevy of calculators to punch numbers into in order to figure out what tire size would simulate your tire size with a gear change. Easier to change tires than gears for a test of that idea.

[Tolle]

Hi all,to answer some of the questions,the sending unit is in cylinder head ,driver side.The rad. is a 32 ford so I guess 3-4 gls.I have checked temps witha gun. Both pump and intake have plugged threads.
however , this is what I`ve done , sacrified a old but working 180 d. thermostat I drilled 2 holes 5mm. in the ring surrounding the core put it back in and fired it up ,I could only do it in the garage but it came up to 180 and stayed there with the fan going on and off ,it`s pouring outside.As soon as the wheather permits I will do a road test and only drive it in Drive and see how  that effects it.I`ll let you know.Then the 195d. gets drilled.
I have been trying to post pictures but it tells me they are too big I make them smaller and ten it tells me, sorry , you have reached your max. upload limit of 270 KB? Is there also a time limit for doing a post .
Thanks All. Tolle

[Leon]

A few years back I had a 68 Torino that I put an AOD into and my mileage was horrible.  The next year I took it on Power Tour I put a Holley 390 cfm on it and mileage went up to 22-24 mpg.  I put a good A/F meter on the car and drove it, and with the old carb I wasn't getting out of the idle circuits until 85 MPH.  With the 390 I was in the cruise circuits at a low rpm and the economy went way up.

[wayne petty]

I have been trying to post pictures but it tells me they are too big I make them smaller and ten it tells me, sorry , you have reached your max. upload limit of 270 KB? Is there also a time limit for doing a post .

a few different ways.....   there is a program called graphic converter...

you can open the image in that and select image pull down menu.. to scale.... and resize the image to within requirements...


i forgot what the size requirements are... but they will show up when you try  to exceed them

or... join photobucket.com     its free....  post your images there...

when you save them...    you will have 4 links to each one...

copy the bottom link that starts and ends with IMG   paste that here and the picture will show up...


like this




and it that does not work....  just do like me and get a bigger hammer... ihqodgihasghsiu,gho9rsyqwuokhf!!!!!

[Tolle]

Finally with waynes help abel to post pictures.did a road test today with my drilled thermostat, no luck, it ran cooler at 140 f. so I will se if flowcooler will send me a balanced thermostat, not many cruise days left over here.Tolle

[Learpilot]

Finally with waynes help abel to post pictures.did a road test today with my drilled thermostat, no luck, it ran cooler at 140 f. so I will se if flowcooler will send me a balanced thermostat, not many cruise days left over here.Tolle

GREAT LOOKING RIDE !!!
Rick