Engine cooling questions.

[JonnyRock]

So I've noticed a that my '70 runs pretty hot. My temp gauge goes up to 250 and it usually sits at about 210, which is 2/3rds of the needle travel. Now I live in a pretty temperate climate, so it hasn't been a big issue, but I know it will be at some point this summer. Twice this year I have had to pull over and shut her off too let her cool down because the needle quickly jumped to 250.

Both times this happened when sitting in traffic. I've read that this is a fairly common problem, and while shopping MSA the other day, I noticed their radiator shroud. Their description says "Light Fiberglass reproduction of the heavy, factory-optional, metal shroud. Helps eliminate the overheating 'in traffic' problems common to the 240Z's." So I went ahead and bought it as well as their radiator overflow kit.

Now I need help with the installation. Has anyone else put one of these on? Should I take out the radiator? What size screws are needed? Where should I mount the overflow tank?

[jtl260z]

So I've noticed a that my '70 runs pretty hot. My temp gauge goes up to 250 and it usually sits at about 210, which is 2/3rds of the needle travel. Now I live in a pretty temperate climate, so it hasn't been a big issue, but I know it will be at some point this summer. Twice this year I have had to pull over and shut her off too let her cool down because the needle quickly jumped to 250.

Both times this happened when sitting in traffic. I've read that this is a fairly common problem, and while shopping MSA the other day, I noticed their radiator shroud. Their description says "Light Fiberglass reproduction of the heavy, factory-optional, metal shroud. Helps eliminate the overheating 'in traffic' problems common to the 240Z's." So I went ahead and bought it as well as their radiator overflow kit.

[ATTACH]23360[/ATTACH]

Now I need help with the installation. Has anyone else put one of these on? Should I take out the radiator? What size screws are needed? Where should I mount the overflow tank?

That shroud should mount in the stock location without any modifications. As far as the overflow tank goes, you can mount it anywhere you can fit it just make sure it is level with the radiator. I had several cooling problems and tried just about everything to get my temp down. Nothing worked until I went with an aluminum radiator, 14" high flow electric fan and an electric water pump. My car won't go above 170 deg now.

Good luck

[hls30.com]

To mount the shroud, remove the fan blade from the water pump pulley, mount the shroud-you'll need appropriate fasteners(check the mounts on the radiator-you may use bolts, short sheet metal screws, or short sheet metal screws and speed nuts.

Then remount the fan blade...done!

Will

PS, also pop the top on the radiator and see if it is growing deposits inside-if it is, take it out and have it tanked at a radiator shop, (take the fan blade off as above) and you may well have cured your issue-but put the shroud on anyway.

[sblake01]

Speaking of fans, some years back I noticed that some cars got 7 blade fans and some got 8 blade fans. Probably the 74-78 factory AC cars got the 8 blade ones. Don't know how much difference it makes but, since then, I've always used the 8 blade fan.

[hls30.com]

In looking at the picture of the shroud, I would take the radiator(whether or not it needs to be tanked) out to make your holes for mounting in the right spot. Careful alignment will allow you the best fit, and I would put some weather stripping/a silicone bead around the contact points(let the silicone dry before installation(I would not glue the shroud to the readiator)-fiberglass on metal will ultimately squeek-might as well stop that issue before it starts.

Will

[Zs-ondabrain]

And when mounting the overflow tank, try and keep it as level with the top of the radiator as possible. This will allow the radiator to suck fluid back in without gravity pulling the fluid back into the overflow. Basically, the longer the straw, the harder you have to suck to get the drink in, shortening the straw or drinking straight from the glass will require less effort (in radiator terms). So higher is better.

Also, Red-Line make a product called "Water-Wetter" it will reduce coolant temps up to 15 degrees in most cases. With my aluminum radiator and the water wetter and high mounted overflow bottle, my temp never goes over 180, even while stuck in 95 degree traffic jam in L.A. after leaving MSA this year.

Dave.

[JonnyRock]

Thanks guys this was just what I was looking for.

[Pop's Z]

I put this shroud on to accompany the 3-core radiator I got from MSA. Be sure to secure the top of the shroud to the top of the rad. I used some stainless wire. The top of the shroud has a tendancy to be pulled into the fan which is not good. When you mount it you will see what I'm talking about. Pull on it towards the fan and see how easily it moves. Also the advice to get the rad. rodded and boiled out is good. My rad. had 73,000 miles on it in a well-maintained car and was seriously plugged. Also the side mounts were both loose and one was actually not attached any more. Since I put the 3-core rad. and the shroud in, my car's temp guage never moves from the left of center.

Cheers, Mike

[snag point]

I just got the shroud about 3 weeks ago. I put it on my aluminum radiator, I welded taps on the radiator so I could fasten it on the radiator. I think it help alot. Last week it got to the mid 90s, my temp, while sitting in traffic, only climbed a fraction of an inch. Jon

[JonnyRock]

Thanks guys, I'm planning on pulling the radiator and getting it boiled and flushed and then attaching the shroud and installing it in about 2 weeks.

I'll let everyone know how it goes, and post pictures of the process. I'd really like to get the "Reviews" section of the website started, because it's a joke right now. I encourage everyone to take a few minutes and post a review of anything they've added to their Z.

[bobc]

Jon,

IMHO, you should be able to get your Z running in an acceptable heat range without the shroud. I think starting with your current radiator is a good course of action. Have it boiled and rodded out if necessary. Pull the water plug on the drivers side of the engine, take off the thermostat housing and run water through the block several times and let it drain out.

I've had these problems in the past, and these steps have solved them. I've also used water wetter and it isn't bad either.

I believe the 8 bladed fan started with the v-3 kit that was developed for the 1973 240Z to help with overheating and vapor lock. That isn't a bad idea either and few if any will notice it. Also make sure your fan clutch is working as well.

Things not to do:

Flush the block with caustic chemicals

Punch holes in the hood to let more air flow through

Take out the thermostat entirely

Think a 160 degree thermostat will solve the problem

Not believe the guage

Ignore the problem until you blow a head gasket!

My experience has been you can spend a lot of time, money, and effort coming up with band aids (I've done it!) or you can focus on the core problem and fix it.

Bob

[beandip]

Johnny Rock, it might be a common problem for some but I have never had any overheating trouble with my '73. I have driven in eastern ore in triple digit heat and had to idle for construction a number if times on that trip and the engine heat gauge never went past the center. The same in town in well over 105* on the freeway with stop and go traffic. This was with the stock 2 row rad. If your radiator is clean and the thermostat is in good working order and not a after market part. Plus a good 13 lb cap. Your engine should run cool. Remember the temp gauge is just a indicator and it may give false readings, verify the high temp you are registering and if it is true , by all means fix the problem before you warp the head. Gary