Here is the layout of the serp belt, pullys, and idler. The alternator bracket is modified somewhat to allow it to sit low and out of the way. Hope this helps.

That whole thing just looks mean.

Did you do anything to stiffen up the chassis?

Why don't we try to make a smaller water pump pulley? That should free up a bunch of space at the firewall.

Brett,

You're right...that thing is huge! I could probably remove the pulley and stick it in a lathe and remove the forward portion. I'm not sure what the GM engineers were thinking on that one. How was the autocross?

Bill

Bill,

If you go with the LS2 water pump and Corvette dampener, you can move everything closer to the block. Also, the LS2 water pump pulley is about 1 1/2" shorter than the LS1 that you have. I moved my idler to the top center so it would fit the depression in the 914 firewall.

Andys

Thanks guys!!! I should be getting my ls2 this week!
andys, How far back is your transmission set from the standard position? Is your firewall cut into as well? Got a link to your build?

Wilhelm,

I'm using a 6 speed transaxle, so the mounting is quite different than the 901. I think its axle position is 1" back from the stock location. I made a 1" hump in the firewall that was necessitated by the higher position of the motor in order to accomodate the 6 speed (vertical height). At a slightly lower position along with the 'traditional' 1 1/4" backset with the 901 trans, the LS2 may fit without any modification to the firewall. I did install an access panel in order to release the belt form the idler. I'll still be able to use my stock backpad.

No build link/page. Let me know what you want to see, and I'll send you photos. Drop me a PM with your e-mail.

BTW, that LS2 is a lot of motor for a 901; longevity will depend a lot on how you drive it.

Andys

I was just thinking that we could machine one out of aluminum, but it looks like GM has already handled the design for us. Give it some time and I am sure the underdrive pulley and serpentine companies will have a nice setup out

I've got a 930 box . So hope I should be good.

Whatcha guys running for clutches? I've read some rumbling the KEP PP and clutches are not doing the job. I want something that will hold the torque, but something my wife could drive without out stalling the engine.

Whatcha running for fuel pumps? I was thinking of dropping a camaro all-in-one pump-filter-sender into the 914 tank.
That will take a little welding to make work though

I'm using a Bosch out of tank pump and an Aeromotive fuel reg. I like that LS2 pump set up. I understand the thermostat is removeable unlike the early one like i have. That pulley looks a lot smaller. I'm sure you can package everything behind the firewall with that set up. It didn't exist when I started mine.

KEP's stage 1 930 PP and stock disc will hold stock LS2 power all day long. It's when you get much over 500HP. Then you have to go even more gorilla on the PP and it gets real hard to push down. Your wife will hate a KEP PP. It will work...but your left leg will get a real good workout.

That water pump pulley is huge. I wish I could put a larger on my engine. Mine is part of the timing belt system. That would slow the flow of the water allowing the water to rest in the radiator longer for cool down in traffic.

Rick are you running a T-stat or restrictor in the cooling system?

A fuel pump from a "F" body fits fine with just a few mods. The fuel level sending unit even worked great with my gauge.
Click to view attachment

No firewall cutting needed........
Click to view attachment


Bob

I'm running a tstat. My last engine had thicker bores. I think I have more heat transfer now after the bore job. They took 3mm out of the bores. I need to play with my cooling system to get the balance back. Maybe a larger surge tank will help. Or I could reduce the tube diameter on one side to slow the coolant transfer.

Sorry for the hi jack Bill

Rick dont get any crazy ideas, your car is running, dont start thinking about turning your engine into one of these insane hp engines, although you could turbo it.
Turbo Alien yeah thats the ticket, welcome home ET.

The large water pump pulley was needed to help stabilize the belt from resonance, thus keeping it in place. Katech engineering has a slick tensioner available thet was developed on the Cadillac CTS-V or you could just use remote electric pumps from the early CTS. Larry

HotDamn... I was just out looking at an old tank and the in tank fuel pump and that is the same conclusion not only for location of the pump but for an aftermarket fuel cell filler. Glad to see my intuition has already been proven correct by you.

Are you not reversing your manifold 180 degrees?

Neat thread.



Rick, I think thats wrong. Given a fixed inlet temp, slowing the flow results in lower efficiency. It results in higher average cooler temp which increases dT and Q. Thats just plain fact. The 911 guys have gone though something similar on parallel vs series oil cooler debates (FWIW: its the exact same amount of cooling, but parallel has far less pressure drop.) The math doesn't lie but some still refuse to see the light because 'their great intuition'. Shoot me a PM if you want more info.

The only reason that slowing a water pump will increase cooling is because the pump is cavitating which causes a loss of flow (corollary: same thing happens w/ 911 cooling fans at high rpms). In all other cases, more flow = more cooling.

Stephen, if the coolant doesn't spend enough time in the radiator, not enough heat will be extracted. I have seen that on cars with no t-stat. If the fluid is exposed to more surface area for a longer period of time it will cool off better.

Wouldn't this apply if the fluid were in contact with the radiator only one time only? If the fluid is exposed to more surface area for a longer period of time it will lose more heat in the radiator, but it will also have more time to pick up heat in the engine. In reality the fluid goes through the radiator multiple times and loses heat each pass. If the fluid goes through slowly and say loses 50 degrees with a one minute circulation but loses 25 degrees with a 1/2 minute circulation (faster flow) there is no difference. I think a more major issue for most folks is not trying to change the efficiency of moving heat from the fluid to he radiator, but improving the effciency of moving heat from the radiator to the air. I suspect for most folks, ensuring that air goes through a large enough core in an expedicious manner will result in greater heat transfer to the air.

Short of anything approaching supersonic flow that is generally incorrect. Cars w/ no tstats can overheat because the pump cavitates w/o the large pressure drop the t-stat introduces, not because the water is going too fast though the radiator. The opposite is happening - the water is going too slow.

From an engineering standpoint, water is a fluid just like air. On a cold day, sticking you hand out the window of a moving car, no one would think that their hand would feel warmer @ 100mph than @ 10mph. Yet, somehow people think water has some magical property that breaks down the rules of physics when its in a radiator (or oil in a cooler). People jump to the (wrong) conclusion based on empirical evidence.

Brett, Im not trying to single you out at all! Im simply trying to state that something else is going on if you're having a problem. The system has to work as a whole. But heat exchangers (radiators) love more flow.

FWIW, I don't know everything:) But I am an engineer and part of my job is designing heatsinks for cooling power electronics. I used to write all the heat transfer eqs by hand. Now we use CFD software (EFDLab) and can solve complex 3d geometries. The basic idea to take from this is: If you can flow more fluid you'll get more cooling. Getting more flow is always the hard part (in both natural or forced convection applications).

The 'one pass' idea applies to steady state. If you can't reject all the energy you put into the fluid in one pass, the system will continue to rise in temperature. Where they reach equilibrium is usually what you're interested in knowing.