Help! Turbo cobra coolant crossover delete problems

[97LaserRed]

I know I'm not the only one that has these issues. I deleted the bypass hose and the factory coolant crossover with just upper rad hose and t stat in it. (With 6 holes drilled in it). I have a set-up similar to a lower gt rad hose. It is modified so it will clear the downpipe. I've blew a few upper rad hoses. Guess I'm building too much pressure. So we gutted the t stat and installed it back in the upper hose with the holes drilled around it to act as a restricter for flow to keep coolant in the rad. I've noticed after ripping on it the crossover tune pushes apart as if it's still building too much pressure. And just recently the heater core blew. Not sure as a result of too much pressure or just old age being a 1997 with 40k miles?

I have not had issues since the gutted t-stat but want to avoid future issues.

What is everyone else doing to their turbo cobra coolant systems?

I'm thinking of getting a MMR Y block and running the AN fitting delete with a expansion tank that doesn't hold pressure like our factory systems do.

Or running a rad from a 94-95 5.0 with a rad cap with a moroso coolant bottle?

 

[97LaserRed]

What temp do you guys see while cruising?

 

[killspray]

i hate coolant issues like that... i had issues last summer (Texas Summers are Hell) with the stock T-stat setup and ended up going with an aftermarket radiator... Still using the stocker?

 

[97LaserRed]

Yes stock rad and water pump

 

[97LaserRed]

Here's my "t-stat" I have now. More of a restrictor.

 

[MGC]

What lower hose setup do you have? I have the tstat in the upper hose like you 2 holes drilled in it, with the bypass deleted and a 2V lower hose, which goes from water pump to the lower radiator and tees off into the expansion tank, expansion tank has a 16 psi cap and a vent line above the cap, it works perfect for me so I'd say you need to add an expansion tank.

 

[BMR Tech]

After extensively testing these set-ups, I have come to the conclusion (for me) that the best way to run these set-ups, are with a pre stat 1/4" bypass line going back into the lower hose, and a 160 stat...with (1) 1/8" hole.

The only time I ever had issues like yours, was when I had a 180 stat....with (2) holes drilled, and went WOT to 6000+ RPM when the coolant temps were <170 degrees.

If you do not have a bypass, or a good expansion tank set-up....you DO NOT want to go WOT to high RPM, unless you are at, or very close, to the stat opening temp.

If you are using the above gutted stat, and still having pressure issues....I have no idea what your issue is. You should not have any over-pressuring issues with a gutted stat like that.

 

[BMR Tech]

Have you tested to see if you are getting combustion into the cooling system? Hate to say it, but that is very likely if you are over pressuring your 40K mile cooling system with an open stat.

 

[97LaserRed]

I have not had issues since the gutted t stat but trying to avoid further problems. I have a few friends with similar setups with a couple holes drilled in the t stat and having the upper hose blow. My lower hose is a gt hose.

What is a good expansion tank. I'm running the one in the above picture along with the other cars that are having issues.

The expansion tank might solve the problems. Do you guys have any pics of your set up?

What lower hose setup do you have? I have the tstat in the upper hose like you 2 holes drilled in it, with the bypass deleted and a 2V lower hose, which goes from water pump to the lower radiator and tees off into the expansion tank, expansion tank has a 16 psi cap and a vent line above the cap, it works perfect for me so I'd say you need to add an expansion tank.

so you think add an expansion tank on top of the current tank I have now?

 

[97LaserRed]

double post

 

[static74]

I'd be interested to know if you have some sort of build up in your radiator thats restricting flow. If you're running a 2V GT lower with the expansion tank T'ed in then you're running the same setup as everyone else who's deleted the bypass.

I highly doubt your thermostat has much to do with it. Something is restricting flow elsewhere in the system. Also, that clamp you have on the upper hose to radiator is poo poo after a while. Change it out for a regular hose clamp.

 

[97LaserRed]

I'd be interested to know if you have some sort of build up in your radiator thats restricting flow. If you're running a 2V GT lower with the expansion tank T'ed in then you're running the same setup as everyone else who's deleted the bypass.

I highly doubt your thermostat has much to do with it. Something is restricting flow elsewhere in the system. Also, that clamp you have on the upper hose to radiator is poo poo after a while. Change it out for a regular hose clamp.

Lol that clamp is actually the tightest clamp on the car. It's newer.

I really think the problem with these systems is there is no bypass hose. The reason other people don't have problems I think is because they have AN fittings and they can take the pressure vs a rubber hose.

 

[wanna_b_03]

I made these for myself and a friend. I've got more in the works if interested

 

[97LaserRed]

Price?

 

[BMR Tech]

Lol that clamp is actually the tightest clamp on the car. It's newer.

I really think the problem with these systems is there is no bypass hose. The reason other people don't have problems I think is because they have AN fittings and they can take the pressure vs a rubber hose.

I've run a system just like yours, on multiple cars - no issues like you are experiencing.

Here is an exact replica of your set-up, that was on my Turbo '98 Cobra.

That was a 170 degree stat, with (3) 3/16" holes drilled. No bypass. 2V Lower Radiator Hose.

I have assisted many people with this cooling configuration, and never any issue.

My last set-up, I did use a lower temp stat (160)...with a bypass, and I really liked it mainly because the consistency of the temps were the best I have ever seen.

 

[wanna_b_03]

I've got to get everything priced out still. I'm guessing 120ish.

 

[97LaserRed]

I've run a system just like yours, on multiple cars - no issues like you are experiencing.

Here is an exact replica of your set-up, that was on my Turbo '98 Cobra.

That was a 170 degree stat, with (3) 3/16" holes drilled. No bypass. 2V Lower Radiator Hose.

I have assisted many people with this cooling configuration, and never any issue.

My last set-up, I did use a lower temp stat (160)...with a bypass, and I really liked it mainly because the consistency of the temps were the best I have ever seen.

ya doesn't make any sense. my car and a few others who beat on their cars as hard as me are blowing the upper rad hose too. I haven't done it since the gutted t stat though.

 

[Cobra8urZ06]

i haven't run a t-stat in 6 years of having the turbo and never had an issue other than being too cool on the highway 120-130*

 

[killspray]

i haven't run a t-stat in 6 years of having the turbo and never had an issue other than being too cool on the highway 120-130*

Bragger

 

[04whitesvtlight]

I made these for myself and a friend. I've got more in the works if interested

Those are perfect I am in for a set