'87 T/A with Dart SHP 400 engine 11:1 comp Dart Pro 1 heads
CVR electric water pump
Griffin 31x19 aluminum radiator
Derale 4000cfm dual electric fans
no thermostat, using water restrictor plate
Running water with 2 bottles of Purple Ice

Stays cool at idle, but overheats (210-220) while driving. Everything seems to be working fine but wont stay cool. Still has the air dam in place. Same set up use to keep the 383 around 170 in the heat of the summer. Can't figure out why this motor wont keep cool. A/F ratio is in the 12's while cruising around. Any ideas at this point will help greatly! Car is built for the track and street.

Thank You

 

being as it is a 400 with Siamese bores I would run a thermostat. not a restrictor. slow the water down in the cooling system.

 

Lean it out for one thing, then play with cruise timing abit. It however seems common to see 200 deg on these things. I know mine does but I have alot of other things adding heat

 

That just on the dart blocks?

 

what's the timing set at? are you loosing coolant any where, head bolts studs?

 

Not the first time i heard of shp running alittle warm. 210 aint bad in warm air tho. In cold air i can barely get my car warmed up

I have tried restrictors, no stat and tstats. No difference in cooling. Electrc and mechanical water pumps

 

Timing is set at 35 total. Mechanical advance MSD probillet with 6al. Probably only mid 20's at cruising. Ran cooler when we 1st put it in. Never seemed to get over 200. ARP thread sealer on the bolts, no sign of any leaking. It would probably go over 220 but we shut it down before it gets there. Thought about leaning it out a little but don't want to get in the 13's A/F with 93 octane pump gas.

 

Forgot to mention its only been in the 50's, 60's and low 70's here in Kansas. Gets into the 80's and 90's once summer hits. Tried all 3 sizes of restrictors trying to get the water flow right and no difference. Brodix intake has divider and wont accept thermostat.

 

Temp gauge sending unit is in the intake by the thermostat housing. How much temp difference is there down on the head?

 

At cruise it doesnt need to be so rich. Even at 11:1 if you have a good cam in it it will be fine. It likely could use more timing and leaner burn.

 

It has heavy silver springs in the dizzy. Going to try switching those to lighter ones and step the jets down 2 sizes front and back.

 

try what Orr89RocZ, suggested. I would also if you haven't make sure the fins on the radiator are clean from debris. Im sure you have tho

 

Do you have the fans with built in shroud? Or are they just fan units tied to rad with most of the back of the rad exposed?

Goin from tpi dual fans to a shrouded ls1 dual fan setup really helped my car. Forced more air thru rad instead of just sucking in surrounding air off the back of the rad

 

I agree with tuning it a bit. I don't have much experience with electric water pumps...but are they really up to being used for a daily driver? I thought most were designed for track only...is the flow enough?

 

35 gpm seems to be enough. I tried high flow mechanical pump vs csr 35 gpm and it made no difference. Electric was not reliable enough for me to have so i dumped it for a stage 2 stewart

 

The water pump is the CVR which is rated at 55 mpg. Just put it on bc it had a Proform on it that was rated at 35, no difference between the 2. This isn't a DD, it is a limited weekend warrior. Derale fans are mounted into a shroud. Changed the springs out last night on the dizzy. Didn't realize it had the heavy silvers. It actually had 39* of timing when I checked it with the lighter springs in. Knocked it down to 33* and dropped the jets in the carb from 72/80 to 70/78. Didn't get over 210 today but it was only 55 outside. Probably going to put the timing back up to 36*.

 

let us know what happens when you drive it again at 36 deg of timing and the jet change

 

Back flowed the radiator and got some crap to come out. Had not done that since the old motor blew to pieces. Put the timing to 36 and now it will stay around 205. The afr is jumping all around so I am going to take the autometer off and put my LM1 back on and see where it really is. I talked to Dart and they said even with the siamese bore of the block it should still stay cool. The water passages have been reworked and scalloped out to allow more water and cooling.

 

I have a stock 11.5-1 400 stroker with a edelbrock water pump, stock rad, stock dual 3rdgen fans, 160 t-stat and a hyperkrap fan switch. Mine is always 160. No matter how hard I run it.