Converted my 91 RS from 305 TBI to 383 TPI

i bought a alum reliable rad http://www.ebay.com/itm/Chevy-Camaro-1982-1992-Champion-2-Row-All-Aluminum-Radiator-RS-SS-Z28-IROC-/291405037588?fits=Make%3AChevrolet%7CModel%3ACamaro%7CYear%3A1991&vxp=mtr&hash=item43d9180014
i have performance fans that run as long as the key is turned

i have the right size injectors but my chip was tuned for a few lbs less
I don't know much about the 'tuning' aspect at all
spark plugs look fine// dont look lean

overheats at idle or highway, i have the correct air dam

coolant seems to flow fine/ tried different temp stats and no stat

i'm getting desperate after 2 summers of it just sitting

 

Did you buy that radiator? When I did my 383 swap, A friend of mine owns a radiator shop ,so I had him build my stock one. 4 core with a built in trans cooler. Ive never had a problem. Are you sure your gauge is correct? where do you have it run to? the head? mines in the intake. temp sending unit for fan is in block. Has to be something simple.... hopefully... its still just a 350 block right?? so just cause its a stroker doesn't mean thats why. ya know? Maybe your thermostat isnt opening or something. I got one of those lazer temp things and shoot it all over my engine to see its temps. pretty cool tool for 30 bucks. Wish I knew the answer. Hate having a hot engine... Id start with making sure the gauge is correct and in the right spot

 

Don't know if it is overheating or just running really hot, but these maybe could help. They'll certainly lower your under hood temp - www.camarolouvers.com

 

1. Air dam intact: Yes

Which leads us to this:
1. Run power to the fans from the battery, do they turn on? If yes...
2. Do the fans come on with the AC? If yes...
3. Are the fans coming on at the correct temp?


Also, my gauge reads 20* hot compared to the temp at the thermostat and there is another member here in the cooling thread tht when his temp reads 180 on the thermostat housing, his gauge is pegged in the red. Good chance your gauge is off. Is your coolant bubbling over into the catch can?

 

Is your timing set correctly? If your base timing isn't right it will cause your temps to go up. Do you have a shroud for your fans? Mine always ran a little hot till I got the ls1 fan setup with a shroud it works great.

 

That's a great point seiplentz and should be checked along with making sure his cooling system is working as it's supposed to.

 

Thanks for the responses. I ordered a lazer temp gun and will shoot that around when it gets here. I'm not sure what I am looking for exactly. checking to see if my rad cap/hoses/heads are as high temp as my dash is reading?

I will also have to recheck the timing to remember. I know I spent an afternoon on it but I don't remember what we chose and why. I feel like we left it at the stock 6 btdc or something because I was reading things about how the tpi works. Any info on timing settings for a 91tpi 383 would be appreciated.

I haven't installed headers yet but I bought some from this site. Installing those would probably help a lot right? More flow.

I made a shroud for my fans and they are 'always on' until I figure this problem out then I can turn them on at 180 or whatever.

I really do appreciate the responses. Been trying for 2 summers to figure this out by throwing money at it. High performance water pump/ radiator/ fans / shroud / etc. I feel like it has to do with the tpi because i am very ignorant of it.I live in Iowa and I called a lot of places but there are no car tuners here for old third gens. The car has a lot of power but I can only drive it for 25 minutes haha

 

I believe some newer V8s are reverse flow for the water pump... wonder if you have the wrong pump? Guarantee someone will chime in on that here when they read it. For the lazer, just shoot it where ever you want to see the temp. so where the sending unit for the guage is hooked up, head/block/intake, shoot that area and compare to gauge. Those lazers are sweet. you can shoot it on each header tube and see which cyds are the hottest, those are the leaner ones usually. some people file grooves or weld in fins in their intake to direct more air/fuel towards the leaner cyd. Lot more to it than just that but thats a rough example. Good luck man.

-Dan

 

All 93-96 LT1's were reverse flow. 87-92 were reverse Rotation. Huge difference.

 

Your stock radiator can cool a 408, so your 383 should be easier to cool.


I'm not entirely sure but 6* BTDC is close. I know that's what my carbed 84 calls for. Once that is set, plug the single wire connector at the firewall back together leave it. You never touch it after it's set. Older cars like mine used a four wire flat connector.


You never answered if you burped the radiator.
What color is the oil?

Do you smell any gas in your coolant?

DId you build the motor yourself? It's possible you have a leaky headgasket, blowing exhaust into the coolant superheating it.


If the shop can tune an LS1, they can tune TPI...they're just being lazy if they say otherwise. There should be a place in De Moines that can help you. If not, I know a shop up in Minnesota that can do it.

 

Does that shop happen to be TPIS? Great guys. Got a lot of my engine components from them. About the water pump flow direction... can you put a reverse rotation pump on a older block with normal rotation and have issues? I got a weiand G team and it keeps blowing gasket on back of pump. but I dont have any cooling problems.

 

No, it's not TPIS, but they might be able to help you out as well.

The "reverse rotation" pumps still had the standard flow pattern of all GM small blocks. You shouldn't have any issues with the weiand. The reason we call them "reverse rotation" is because they spin backwards relative to the motor. In a V-belt the belts spin the same direction as the motor. In serpentine motors, 88 and up, they spin backwards but keep the original flow.

In 93 they reversed the flow to cool the heads first.

 

Thanks for the info! I did some research on the weiand and some guys say there are bad batches every now and then sense they are made in china now. Going to put a straight edge on the back to make sure its flat. maybe drill and tap a few more holes for bolts to hold cover. Also...I didnt start thread. Im not having cooling issues. Dont know what happened to the guy.... Anyways, Thanks again!

-Dan

 

I am out of town for work this week so sorry to keep you guys in limbo. really do appreciate the help. I believe my block was out of a 93 1500 truck. I will check under the car and find oit exactly what block it is but I never thought it mattered. I think I ended up using a Stewart stage 3 water pump. I really don't know but that sounds right. No idea if it's the wrong flow or not. sorry that I'm not all that knowledgeable on these things. even though I do all the work on the car I still don't know a lot haha

 

Yes I burped the coolant. No gas smell. Not possible the heads exhaust is superheating the coolant. Nothing strange that I can find at all

 

What cooling fans do you have?? Alot of those aftermarket elec. fans are junk and do not move very much air.

My go to fan is the late 80's, early 90's lincoln mark viii, ford taurus, and tempo, 2 speed single fan. Pick it up out of a junk yard for $25 or less, moves 4500 cfm of air

Also how is your fan wired? 12 volt elec motors turns clockwise with 12 volt to +, they turn counter clockwise with 12 volts to -.

Where is the fan mounted? On engine side of rad. or on bumper side of rad?

You need the fan on engine side of rad and wired to pull air through the rad and blow onto the engine

 

If you don't have the part number to identify the sbc long water pump. You may need to look for a casting number to identify it or pull the back cover and see what the impeller is designed for a serpentine reverse rotation or v belt standard rotation. I would think the impeller cover gasket is the standard fuel pro 13032.

 

if the radiator you posted was the one you bought then I will say get a 3 row radiator a 2 row is not going to cool your 383

 

Flow is correct. Rotation is correct. Fans are correct 4000cfm fans with a shroud. Plugs look good. Overheats idle or highway. Radiator is only a 2 core.

What should I check next? I have replaced sensors and stat. 2x sensor and 3x stats. followed up with temp gun readings

 

I would be running a 3 core radiator and make sure your lower radiator hose is new as well with age they tend to get flimsy and squeeze closed

 

Do you still have the spring in the lower radiator hose that keeps it from closing shut?

FWIW, I used a brand new stock radiator with my 383 and had no problems with the cooling. I added an after-market temp gauge and checked it before installing (engine sits at a rock solid 190º). The original ac condenser fins were clogged with debris so I just left it out. I'm going to assume yours doesn't have the condenser but mentioned it just in case. It's a good idea imo to recheck the basics that are often overlooked.
Have you pressure tested your cooling system, or tried a different cap? You might be able to rent a tester at a local auto parts store.

 

lower rad hose is new and has the spring. does not buckle when i crank the rpms and the engine is warm/hot. the cap that came with the rad seems fine to me but i have access to a tester for that. i dont have a leak so i havent pressure tested the system. should i?

i cleaned my condensor fins before breaking in the 383. will probably remove it today after breakfast

 

So that sticky link in the cooling section says bolt in alum 3 core rad. i just really messed up because i thought i was buying the 3 core but clearly own a 2 core alum champ rad. will be heavily considering ordering the 3 core today

 

Yes, it can leak internally and the pressure is needed to help it cool.

 

What temp is it running at? What is the temp going into the radiator and what is the temp coming out? You should see a 15 to 20 degree difference. Since you run electric cooling fans I would also check that the fan blades are orientated to the correct rotation. If a fan is changed from a puller to pusher the fan blade must also be flipped. May your was wrong from the factory. What brand of fan are they most electric fans aren't what they say as far as cfm goes. I think that 2 core radiator should be fine unless you are running a real hi compression race motor.

 

i have a pair of flex-a-lites in a shroud. I upgraded to a 3 core rad but noticed no difference. Replaced my rad hoses with aftermarket reinforced ones just because and no difference. I have a stewart stage 2 water pump. http://www.summitracing.com/parts/emp-23123/overview/ and the pully for the water pump is smaller than my cranks pully but at idle i see the temp gauge climb fast as hell. So I hold the rpms higher to keep the car at 220 for awhile but eventually that fails.

i also removed the ac condenser.

I'm baffled. Completely out of ideas. Is it time to tear into the engine?

 

I see that pump is a counterclockwise rotation one. I don't know what belt setup you are using, but are you sure it's spinning in the right direction? If you are sure, maybe the pump was mis-labled and it has the wrong direction impeller on it.

 

Reminds me. I bought a set of rear shocks from Summit last year. Both boxes were marked correctly, but when I went to install them I noticed one shock was marked with a different p/n than the box it came in. So it's probably not a bad idea to pull the pump and make sure somebody didn't slip a clockwise rotation pump in the wrong box. Long shot...but it sounds like you tried everything else.

 

make sure your fans are pulling air into the engine bay and not towards front of car I've seen that before by hooking up power backwards before

 

Run down the cooling system basics;

Check condition of the radiator:
- fins clear of debris, not bent/mangled
- no visible leaks from seals or hoses
- radiator cap gasket in good shape
- not blocked (leaves/debris)
- with engine at temp check for cold spots on the radiator (usually at the bottom, evidence of blocked passages)
Check condition of the air dam:
- not missing/broken
Check condition of the fan(s):
- if electric, check for proper operation
- if mechanical, fan clutch not worn out
Check Hoses:
- Not kinked/collapsed/leaking/steam leak. Look for evidence of pinhole steam leaks in the form of yellowish green deposits or "snot" at gasket areas and around hose ends.
Check water pump:
- no sign of leakage from weep hole
- no odd noises
Check coolant:
- proper color/mixture
- proper fluid level (has the system been "burped" to remove all air?)
- does system pressurize (engine at temp, thermostat open, radiator cap on and upper and lower hoses not soft)?
Check heater:
- does hot air blow from the vents with engine at temp (heater core not clogged?)

Other things that can effect engine temp are detonation, trans issues (auto trans generate a LOT of heat), mineral deposits in the engine/heater core/radiator that block coolant flow (from running tap water), leaking/blown head gaskets, and improper timing. Beware of head gasket failure where hot cylinder gases are allowed to leak into a coolant passage. It won't always show a change in coolant color or smoke in the exhaust, but you may see excess coolant pushed into the overflow bottle. It will also create air pockets in the cooling system as it pushes the coolant out. A hydrocarbon test of the coolant will diagnose this. It may be fixable with head gasket repair with sodium silicate, but will probably need new head gaskets.