FZR400 guys: F3 rad v. FZR60 rad

Have you tried both? Ryan is running an FZR600 rad, and I've got an F3 rad, and his temps are happy...mine aren't.

Thoughts?

 

Dave I would get the FZR Radiator (only $15.00 right now couldn't hurt) . I am not sure about how they swap if they are a direct swap or not but it couldn't hurt at that price, even if you had an extra one.

 

Thanks for that...it's actually already on my watch list

I have (3) F3 rads, so I dont' really need a 'spare' per se. I'm just trying to do the best I can to keep my bike from blowing up.

 

I think I ran a curved ZX-7 (early 90's) rad on mine and NEVER had any cooling issues

 

I think mines a 93 gsxr 750 rad. Had to fabricate some brackets out of 1"x1/8" aluminum stock from the hardware store but it wasn't to hard to do. Could talk you through it on the phone if you're interested.

Oh, you do have to trim the body work alittle too.

 

Always wish I had one of these. They look really nice but at the time when I was looking for something bigger they were pretty pricey, could be cheaper now

 

I appreciate it...I'm gonna stick w. what I have for now. I just got done fitting a belly pan...gonna try it at Nashville w. no lowers/mids on it and see if I can drop a couple of degrees that way.

I'll update after the weekend!

 

Is it just running on the hot side or are you pushing water?

If running on the hot side, what temp?

 

Well, it's running a bit hot...nominal temp seems to be about 206-210. It seems that if I get just exactly the right amount of coolant in there, it doesn't push a significant amount out...until I stop for post-tech, at which point it goes up to 235 and blows water everywhere half the time.

If I could just get it to have a nominal temp in the 193-200 range, I'd be happy. I am a bit worried, because the hottest ambient temp I've ridden in thus far was about 75f...what's it gonna do at Road Atlanta in July I wonder...

 

hey diet

diet checkout my post in Tech "rad" that was meant to be a reply in here but had a brain fart

 

Re: hey diet

I'm not, mostly because the fan won't fit behind the F3 rad. Do you use the fans at speed on the track? I've always thought that a fan behind the rad would actually impede cooling at high speeds, and was only useful when the bike isn't moving...

...thoughts?

 

When your on the track you should be going a faster speed than the fan can pull air through the rad. On the grid and coldown lap though, it could be nice.

I think my bike may still have one on it.

 

Dave,

I run the F3 rad. on my 400 SBK, and her on track temps. run in the 185-190 degree range even on hot days. I'm thinking that for your bike in basically SS trim to be running those temps., you are having some other cooling issue besides what radiator is on the bike. I know you've been through most of the cooling system, but you need to check everything from radiator cap, water pump to head gasket. Watch your coolant level in the overflow bottle, make sure all the water it pushes out when hot gets sucked back in when it cools, if not you're looking at a head gasket issue. Check the water pump and make sure the impeller is still attached to the shaft, they sometimes come off. Just go through everything. The F3 rad. should be enough cooling for that motor without a fan.

Good luck hunting,

Scott

 

Thanks.

The only thing I haven't done is putt the water pump, which I'll do tomorrow if it's not better.

Also, the bike hasn't ever sucked _all_ of the coolant back out of the overflow bottle. I've looked at it literally every time I've ever ridden it, and it always leaves a few ounces in the bottle...well, when I say "always," I've only had the bike a short time, but I'm talking about over the course of 3 race weekends.

Is that bad?

If this motor has a bad head gasket, I am almost definitely going to kill myself.

 

Make sure the cooling system is full, leave a little in the oveflow bottle, maybe to the low level line, run the bike say one practice session, look at the level in the bottle, let the bike cool all the way down, look at the level again, it should return to where it was to start. If the level does not return to where it was to start, lower = probably a leak somewhere, higher = head gasket. The reason the higher level is the head gasket is that if the head gasket leaks compression into the water jacket, it will push more water out of the cooling system than it would from just heat expansion. When the bike cools down it will pull the water back in that it pushed out due to thermal expansion but it will not pull the water back in that was pushed out due to the compression pushing it out hense the higher level in the overflow bottle.

Hope this helps,

Scott

 

Thanks for that...

I have a bad feeling about this. the first weekend I rode it (Nashville last year) it was pushing enough water into the catch bottle to overflow, and it's done that every time I've ridden it. If I leave the cold coolant level about 1.5" below the cap, as opposed to "full" it will typically not push that much out.

But, from what you're saying, I should be able to run it topped up, completely full, if it's working properly and doesnt' have a bad head gasket.

On a side note, does anyone know if Valley uses a steel head gasket like Speedwerks does when they build FZR motors? Thanks.

 

Dave, I really don't think it's head gasket. I've had those and you overheat quickly. I still say richen the carbs slightly, I've run hotter due to being too lean before. The water pump is worth a look see also, teenage water pump that it is. Beyond that, check with Valley Racing, it's their motor.

 

I've already shimmed the needles, so we'll see if that has any effect...hell at this point I'm willing to explore the Dark Side of The Force, if it will make my bike run cooler

Also, I have a known-good water pump with me in my stuff, so I'll be pulling the existing one tomorrow morning to check it out. I was going to do it last night, and I just ran out of hours.

We shall see!

 

Dave - I'll bring a spare water pump with me to Nashville. Make sure your rad cap is good (but I doubt thats the problem). Remove the thermostat, dude. I run the FZR600 radiator, but I have mounted an F3 radiator before on my previous 400. Both are large enough. I personally dont feel the 400 radiator is large enough to begin with. Replace the coolant overflow hose. If there is a nick in the hose, it will force water out, but cant suck it back in and will just suck air. I'll help you try to work this out this weekend.

 

Thanks Ryan...I actually have a pump with me in my stuff, so if that's the issue, I'm good. Also, the cap is good, but the hose idea is a good one...I never thought to check that.

Also, I did the Ryan Nelson Signature Series Thermostat Mod® last night, so cross your fingers!

:up: