V-8 Conversion Cooling

[ntsqd]

Was it me I would put a second OE temp sender in the mechanical's location, and then swap the wire while taking the readings off the Scangauge. That is the closest that you'll reasonably get to identical sensing of the temperature. OE and aftermarket electrical senders are not necessarily made to the same standards. The OE parts have tolerances that they have to conform to, so you know that you're getting a consistent part. The aftermarket senders may have stds, but they aren't published and aren't driven by emissions compliance requirements so who knows how good or bad they are. I suspect that is the source of your bias against aftermarket electric gauges.

The IR temperature gun that we had at work was very sensitive to the condition of the surface that it was reading. Bright machined aluminum vs. oxidized machined aluminum vs. flat black painted machined aluminum were vastly different numbers. I didn't know that you could measure air temperature with an IR gun. I would suggest that if you're going to do this that the background be consistent. We found that the flat black painted surfaces consistently agreed with our other temperature sensing methods.

 

[Elbert]

given the conditions and ambient temps I have no doubt about that I was somewhere in the area of 220F. I'm not questioning the difference in the gauges...or sending units. I did not have the scan tool with me so I don't know what temps the sender at the intake manifold "reported"... I have scanned my LC at times and have noted a difference between the PCM value and the gauge value. I have also noted the same issue with my old 91 K1500 pickup I had at one time. Not a big deal to me, just something to be aware. Lke I noted...the readings are from different areas of the engine.

Regardless of the debate with the guages...It was / is my belief that the fan clutch is not working as it should. The gauges in question have been on my truck since day one....with the old electric fan setup etc.

When you are off road on the trail for an extended peroid and you are in low range 4 wheel drive climbing some fairly steep hills and you don't hear the fan clutch engage clibming the hill and the temp shows to be climbing north of 210F you start to wonder what's going on.

I plan to mofiy the shroud..(and we'll see what happens).

 

[Elbert]

see the link posted on this thread I posted in the hard-core section.

https://forum.ih8mud.com/hardcore-corner/408679-v-8-swap-cooling.html

 

[Elbert]

decided to modify the fan shroud by reducing the amount of the fan blades covered. I hated to cut into it, but it seems to be the only solution to me that I should try first, given my experience with the truck so far . About the time I was able to finish up my partial "red-neck" custom modificaiton...the truck starting running really rich (raw gas out the tail pipe). Well to say I was pissed is an understatmetent (no connection to my fan shroud mod). Raw gas out the tail pipe. The last time this happend, it was the MAP sensor. I'll get my freind at the GM shop to look at soon, no codes showing. I'm purely guessing but think it may be a leaky injector, coolant sensor, or 02 sensor. Hopefully its something "cheap" as I'm growing tired of throwing money at the engine setup....soem of the sensors are old...so I guess that may be part of the issue.. We'll see. No luck today.

Appreciate the feedback from eveyone and comments on teh hardcore section thread (see link above).

 

[Elbert]

Your shroud looks pretty similar to the one Ron made for me at Custom Cruisers. I'm also using the factory 5.7 clutch fan but am using an aftermarket coolant bottle off the shelf of my local parts store.

I'll have to check my receipt, but I think this is the hose I used: Summit Racing SUM-390024 - Summit Racing® Stainless Steel Flexible Hoses - Overview - SummitRacing.com

Yours is looking good.

maybe I asked before...but what kind of temp ranges are you seeing?

 

[Elbert]

More Pics

what kind of temp ranges are you seeing with your setup.

which radiator are you using?

 

[OyajiJon]

Mine rarely moves off of 195* (I have CA emissions, so 195 t-stat). One day it was very hot, and I had a long climb where it got up to 210*. It didn't stay there long, and it's important to note that the fan clutch never kicked in. My engine is acting up, and I don't think the fuel trim is right. I've been fighting this battle for a while, so mine isn't a good one to compare it to.

I'll be changing out the fan clutch, soon, and will put in 2 new O2 sensors forward of the cats today. I may be able to provide a reliable comparison if I can get the frickin' frackin' thing running right. Sorry...

 

[Elbert]

The MKVIII fan is a perfect fit for a 19X26 radiator, I thought the stock radiator was a bit smaller (at least for a 40) It is also pretty deep, but you could trim the shroud a little to reduce the depth a little.

Yeah..I've seen some write-ups on that fan...seems to be a very good performer.. But it also is fairly thick in depth (like close to 5 inches?)

Saw some video of the fan working on some mustang hot-rod site...for electric fans that seems to be one of the best I've seen.

 

[Elbert]

see my previous post / pics on fan shroud.

I plan to reduce the thickness of the fan shroud (distance the fan shroud covers the fan blades). One source I've come across reccomends 50% fan blade coverage by the shroud.

The other modificaiton I plan to do is to potentially add something like 1*1 square tubing (size may change) to make a square frame type setup to basically space the shroud back from the radiator a little, which hopefully would allow for better air flow scross the entire surface area of the radiator. Based on others comments and in looking at the stock fan shround and some others...I think I may have limited the air flow a good bit around the edges of hte radiator core...when the radiaor is this small...I'm concerned about that.

On face value not much difference between my truck and rover's in this thread..other than he has 5.3 engine and his shroud is different, and the difference looks to be that it allows for better air flow across the entire radiator core, while mine appears to restrict that to some degree.

I thinking that I may come up with something that would allow me to remove the shroud without having to take the radiator out (as I have to do now. Due to space restrictions between radiator core and front of engine. Other difference is that it would appear that Rover's engine sits farther back / closer to the firewall than mine...better room. If I ever switch to NV4500 trans...the present engine location is going to move back 3 to 4 inches, and I'll get new driveshafts made and cut the floor if I have to. I would like to run full GM drivetrain(engine & transmission)...maybe keeping the TC though (to allow for yota differentials) and getting rid of the mark's adapter.

 

[Elbert]

more shots of it installed. Note the burrito tray It was kind of an accident that it turnied into one, but it works really really well. The upper hose was from Napa, PN 8991 and it fits really well. I kind of had to squeeze it on the stock radiator inlet, but it works.

Rover...

the more I look at that shroud...the better I like it...YOu should cut up mine and mod it for me ...

I do think one of my issues is air fllow across the entire radiator core... I'll see if my friend and I can come up with a good solution..right now it would seem that the addition of something like 1*1 square tube or whatever works. to space the shroud back from the core a little would be the "cool" thing to do.

I bet it took you some time to mod teh shroud as you did...and after reivew it does appar to be a good bit thicker (after your mods)..

 

[Elbert]

update... if you read this without looking at the other related thread (s).

I had my friend make me a new fan shroud and I'm back in business. New shroud doe not block air acros the core and seems to work better. Issue solved with new fan custom fan shroud. Still running GM OEM Fan and fan clutch along with 4 core brass type replacement radiator.

Did modify the radiator if forgot to mention that in this thread., lower radiator hose fitting is moved to the far passenger side of the radiator core , to clear shroud and fan, upper radiator fitting was changed to mate to the size of the GM hose...either 1.5 or 1.25, I'm using the upper hose off a GM 99 pickup or SUV with 5.7. We changed the lower radiator hose but we lost track of which one we ar using, so when its time to replace it will be a classic "goat rope"...