SBCGENII

In jmucks response he said his condenssor was moved forward some. That could be what your missing. Also I have seen blowing out the condenser make a big difference as well.

inspector12

Me and Alan have talked so I was just giving him some up to date info for him. Both of mine were AL. For sure he's build a great car and we've talked and can't figure out why his runs so hot. Although he's not far off Bill's LSX block temps. I think they are almost identical to his temps.

ajrothm

No idea why mine runs so hot. It always has since we built the 402 the first time. Without the AC on, it will rarely go over 210* even on a 100* day, idling for a long time, but you hit the AC any time, it jumps up 15* minimum...

Even today running errands in the car, lots of stop and start, shut it off/start it up stuff, AC on the whole time, it was running 220-225* and it was only 88* outside.

I've got no idea.. I will say when it's cooler out, and I don't run the AC, it runs in the low 180*s most of the time.

It really just seems like air flow is terrible, even at highway speed it's barely enough to maintain a decent temp with AC on when it's 100* outside.

SBCGENII

Have you tried playing with the Timing or AFR with the ac on? Have you checked the outlet temp on the radiator to verify it isn't cooling?

SBCGENII

It justs seems crazy to me that the blower could be causing such an increase of load on the engine that the temps would be like that. Have you tried running it without the blower? Sorry if you have already posted this.

0Tom@Dewitt

http://www.dewitts.com/blogs/news/81...ersus-mark-vii

schpenxel

He pulled the whole intercooler off. Still got stupid hot.

SBCGENII

I was talking about taking the blower belt off and see how hot it got without the blower.

ajrothm

No I haven't tried it without the blower. If I did remove the blower and the temps cooled down, that still wouldn't help me, it's always gonna have a blower on it. As for the timing, it's 24-26* at idle, AFR oscillates between 14.8-15.3 AFR in closed loop.

I've got to figure out how to cool it with the blower on it.

Next test will be the Lincoln fan, then depending on that test, I'll pull the IC again and see if it helps with whichever fans prove to be the strongest...

As for right now, I'm just driving the crap out of it until I get some days off to experiment.

Today, 85* ambient, AC on, I was 198* on the highway. Ambient temps make a HUGE difference on this car, more then I have ever seen on my other cars. This tells me my cooling system is severely taxed.

95wht6spd

Just for kicks, since you are going through all these tests/changes, try putting the regular front plate cover back on. (if you have one). Maybe it is more about air flow, than volume. Maybe you are getting a lot of turbulence, of course this doesn't impact the problem when idling. Just an idea.

screeminc5

I think I am in the same boat as you with the cooling issues. I have an aluminum Ls6 block with a YSI. Dewitts cutdown, stock dual fans with a/c condenser and A/A intercooler. When its over 95 out it wants to get stupid hot. Basically gets to the same temps you are at. It has been over 100 the past few days so I have tried wiring the fans to come on as soon as I key on. I am going to try it out tomorrow and see if I see any difference.

ajrothm

The struggle is real bro....

I haven't had time to mess with mine, I have been driving it everyday to work this week, dodging traffic. Today was 94* and I saw 210* idling with the AC on but I wasn't idling for long...and it will climb fast. 100* days? Sh*t this thing runs 220* on the highway with AC.

Just eye balling the Lincoln fan, the sucker is huge, I don't know how I'll be able to mount it on a 15" core radiator without it looking terrible.. The shroud is 19" tall. I'll do it for testing purposes, if it helps temps, then somehow or another ill make it work. Maybe hire Dewitts to build me a shroud or something to box it in.

Forcedvert

If you look at the fan curve link posted bt dewitts the fan you are trying to use does not flow more cfm at any static pressure, but both fans flow much better with lower static pressure on them. I'm thinking it may be cheaper to buy a spare hood to cut vents in to allow air to flow easier or find some other way to get more air out from under the hood. Just a thought.

Good luck

ajrothm

Well with my experience, I don't put any stock in fan flow numbers either free flow or with static pressure. Honestly I think it's all advertising propaganda. I do know that MANY people use Lincoln MKVIII fans on hot rods that are very hard to cool and they work very well. I also know I installed a Lincoln MKVIII fan on my buddy's 69' BBC Vette that had a Dewitts radiator/dual spal setup and it would not stay cool with AC on it.. After putting the MKVIII fan on it, it idled 15* cooler on average. THAT is my comparison for the MKVIII fan to the Spals.

At this point on my C5, the dual Spals are definitely better then the 17" brushless, they seem to pull a ton of air, but it's still not enough. The Lincoln MKVIII fan may very well not be any better, hell it could be worse... Or it may flow more air and it still may run hot... No telling. I do know that testing on your own vehicle is the only way to know what really works or not, not by reading spec advertisements or seeing what other people did on their cars that "worked".

I'll test, post, and reveal truths... I keepz it real.

ajrothm

This is the MKVIII fan on my 71'. 650hp iron head/iron big block, with AC. 98* ambient temp and this thing will idle/cycle all day long at 180-185*... And if I hit the override switch and force the fan to stay on, it will get down to 178* or so and stay there.. This fan is a monster.

I hope to have some luck with it on the C5. I'm not overly optimistic but... My take on it is, if the Lincoln fan doesn't cool this thing at idle, nothing will... And at that point, it is what it is.

Forcedvert

Like I said before, I hope it works, I have the same problem in Florida. I was simply saying I did not see enough of a difference (imo) to think it would work much better either way. The real world test you speak of would probably depend on how efficient the fan moves the air across the radiator and if it does not fit well I would think it won't be much better. I understand it's not all about cfm only. I still think getting air out from under hood efficiently would help quite a bit.

Please don't take offense... it's just a guess on my part. Guys like you are how things are improved and I appreciate your efforts.

I'm an ac guy not a engineer, but I do know you can't shove more air in than you take out.

jimbos'ss

Subbed. Been looking at the Mark VIII fans for a while.

ajrothm

Not offended at all bro.. We are all in this mess together. And I agree, if we can't get the air out, it's not gonna flow thru.

I think with my radiator laid back so much, the fan/air flow is pointing down smack into the front of the engine, and not a lot of room to escape.

A heat extractor hood "may" help some but... It would be a lot better if the extractor pulled off of the radiator flow thru like on the C7Z. No doubt the under hood temps are extreme, especially on my car with 800* header temps, however even with the hood open, it will hit 230* with the AC on after a long idle period so.....can't extract more heat then that.

I always thought for sure my problem was the IC restricting the flow to the radiator but....after removing the IC and it still running hot, I'm not sure about that theory now...

I'll try to figure out a clever way to temporarily install the MKVIII fan and seal it to the core well... If it helps, I'll permanently install it. If not, then I'll stick with the dual spals and relocate the IC into the crossmember.. At that point, other then a heat extractor hood, there is nothing else I can do to improve cooling, other then going to E85.

schpenxel

Ah just run it off straight methanol. Problem solved

Chicago1

interested in the MKVIII fan...Anyone ever due a setup on the c5?