V1 Balance Shafts / Electric Water Pump

[duthehustle93]

Good morning!

I'm in a bit of an analysis paralysis situation, and would love to get input to help sway me one way or another. I'm currently rebuilding the LNF from the unfinished #05 kit I recently picked up (the engine was seized) and have it currently stripped down to the bare block. The car will be primarily a track car but I would like it to be street-able. Anything north of 300HP/TQ and I'll be happy, so my plan was a stock rebuild+a tune and call it a day, but I've got a case of the "while-I'm-in-there" and am debating a few options...

1) factory balance shafts, factory mechanical water pump
2) ZZP neutral balance shafts, factory mechanical water pump
3) OTTP balance shaft delete, electric water pump ("coolest" but the most amount of work, and I have a long way to go to finish this Goblin).

Any input (opinions or experience) is appreciated, and I have a couple specific questions...

1) Has anyone had any luck with adding an electric water pump on an LNF? I found one post on a cobalt forum, but I think there may be a better solution since there's more room in the Goblin frame. To avoid re-engineering the coolant routing, it would probably be easiest to put the electric pump-in line of the hard pipe between the WP/thermostat housing, but the turbo and exhaust manifold make packaging in that area really difficult.
2) Does anyone have experience with solid mounts + neutral shafts/balance shaft deletes? I'm curious how bad NVH is at idle w/ solid mounts and no factory balance shafts.

 

[Sebnuts]

http://dfkitcar.com/forum/index.php?threads/balance-shaft-delete.3068/post-60873

 

[Gtstorey]

(1) Ready for electric water pump now.. | DF Kit Car Forum

 

[Sebnuts]

I don't have the balance shaft deletes or neutral balance shafts, but you're going to need a bigger turbo and heavier valve springs so you can rev higher if you want to take advantage.

 

[duthehustle93]

I don't have the balance shaft deletes or neutral balance shafts, but you're going to need a bigger turbo and heavier valve springs so you can rev higher if you want to take advantage.

Thanks for the input! That's a good way to look at it, there are much lower hanging fruit for my lower power goals. I'll just stick with option 1, get it driving as a stock LNF and can easily add more power later with turbo/valve springs/tune without needing to remove the engine again.

 

[duthehustle93]

(1) Ready for electric water pump now.. | DF Kit Car Forum

Thanks for sharing; I saw that thread but unfortunately I'm not sure how I would easily adapt that to an LNF setup (It's likely from my lack of experience in this area). It seems that they are NA or SC which leaves room to tie into the tube between the thermostat and water pump... it would be tricky to work around the TC manifold using hard lines and I'd be reluctant to use soft lines near a turbo manifold. The WP could be packaged on the intake side of the head, but it would put then switch the block/turbo feed from the "push" side of the pump to the "pull" side of the pump. I'm sure it's doable, but I was curious if there was someone with an LNF that I overlooked that has done it, and if the juice is worth the squeeze.

 

[Rauq]

Out of curiosity, what's your motivation for an electric water pump? I don't think anyone's had any cooling issues on a built with a fully functional cooling setup.

If it's power, as has been stated previously, there are easier ways to get more of it than an EWP and NBS.

 

[duthehustle93]

Out of curiosity, what's your motivation for an electric water pump? I don't think anyone's had any cooling issues on a built with a fully functional cooling setup.

If it's power, as has been stated previously, there are easier ways to get more of it than an EWP and NBS.

The motivation for an EWP was mainly in conjunction with a BS delete.. I personally wouldn't do it with NBS's or factory BS's. The drive would be a few nice-to-have's: getting rid of the BS chain/not needing to make idlers (if doing a BS delete), a few free HP, but mainly being able to do a cooldown with the engine off would be awesome. Tracks out here in the summer are 90-110F and being able to park it and run a cooldown cycle after a session would be nice, but definitely not a necessity.

This is my first F/I build... I'm so used to the N/A mindset of focusing on the little things and small gains adding up. The idea of not doing a bunch of little things when a motor is opened up is pretty foreign to me so I appreciate the reminders of focusing on boost and a tune... seems a lot easier and cheaper. What I'm hearing is I should probably just focus on rebuilding this motor as a factory rebuild and it'll reliably meet my end power goals.

 

[mike_sno]

There is this shortcut of the small passenger room heat exchanger. Would it not be possible to add a electrical water pump in that loop and switch it on after the engine is switched off to circulate some water and cool it faster?

 

[Rauq]

For what it's worth I ran 20 minute sessions at Road Atlanta in 90° ambient temps and ECT stayed a solid 190°F. Half a lap of warmup at the beginning (which is really cooldown from heat soak) and half a lap of cooldown at the end were sufficient for me. I think people underestimate how easy it is to keep an engine cool when the block's in open air and not stuffed in an engine bay.

 

[Dale E]

Electric water pump can be mounted in the radiator hose at the front by the radiator/steering rack area. Close to the battery for adding a fuse/relay and dash switch if you want.

 

[duthehustle93]

Thank you all for the replies. While I have a few experienced members in here, can I get a second set of eyes on my updated plan? Between this thread and forum lurking ... my plan is now a "stock+" rebuild: factory balance shafts, mechanical water pump, GM stock main+rod bearings, GM stock rings, new factory loaded head, stock oil pump, GM timing chain/guides (maybe ZZP upgraded guide??), upgraded timing chain guide bolts, GM 3 bar MAP, and a tune. Is there anything that I overlooked that I should do while I'm in here, if my end goal is reliability on circuits at ~330-350 HP/TQ on 91? The engine is an early '08 LNF with no signs of coolant/oil mixing.

There is this shortcut of the small passenger room heat exchanger. Would it not be possible to add a electrical water pump in that loop and switch it on after the engine is switched off to circulate some water and cool it faster?

Neat idea to utilize the heater core loop. If I'm not mistaken, without modifying the loop, wouldn't this loop bypass the radiator?

For what it's worth I ran 20 minute sessions at Road Atlanta in 90° ambient temps and ECT stayed a solid 190°F. Half a lap of warmup at the beginning (which is really cooldown from heat soak) and half a lap of cooldown at the end were sufficient for me. I think people underestimate how easy it is to keep an engine cool when the block's in open air and not stuffed in an engine bay.

That's definitely helpful info.. aluminum block in free air I'm sure helps as well.

Electric water pump can be mounted in the radiator hose at the front by the radiator/steering rack area. Close to the battery for adding a fuse/relay and dash switch if you want.

It'd be awesome to move weight forward as much as possible, but with the thermostat closed + pump on, would this collapse the soft line that runs the length of the Goblin on the pumps' "feed" side?

 

[Gtstorey]

Not sure that any pump layout is going to work to cool the engine when the thermostat is closed. I would think the temp control on the pump would be set so that doesn't cut on until the thermostat is open.

Are you replacing or reusing the stock rotating assembly. If replacing, what is the cost difference to upgrade to forged components over GM parts.

 

[duthehustle93]

Not sure that any pump layout is going to work to cool the engine when the thermostat is closed. I would think the temp control on the pump would be set so that doesn't cut on until the thermostat is open.

Are you replacing or reusing the stock rotating assembly. If replacing, what is the cost difference to upgrade to forged components over GM parts.

I'm already un-sold on the EWP, but I would imagine thermostat closed + pump on would be a warmup condition. I believe you still want some coolant flow, but bypassing the radiator, so you aren't stagnating in the block and the turbo is getting coolant flow. This is just me regurgitating what I read online though.

I probably should have clarified that the rotating assembly is in excellent usable shape. So unless it's a worthwhile upgrade, I would like to use the stock rotating assembly.

 

[Gtstorey]

There is bypass water, just not enough to cool anything.

 

[mike_sno]

My point in electric cooling is also more: I have my Garage under air. Probably the same as @Desert Sasqwatch has. If I drive the car, park it outside for a few minute and get some of the heat out of the system before I park it in the garage, that would help me with keeping my garage temperatures low. Eliminating the mechanical pump would be a nice side effect.

Regarding the coolant loop. I have not seen a full coolant diagram, but the heat exchanger loop should be open all the times independent of the thermostat or??

 

[Gtstorey]

My remarks are in regard to keeping the engine cool, the main purpose of a cars cooling system. The purpose isn’t to keep the coolant cool.

 

[Desert Sasqwatch]

My point in electric cooling is also more: I have my Garage under air. Probably the same as @Desert Sasqwatch has. If I drive the car, park it outside for a few minute and get some of the heat out of the system before I park it in the garage, that would help me with keeping my garage temperatures low. Eliminating the mechanical pump would be a nice side effect.

Regarding the coolant loop. I have not seen a full coolant diagram, but the heat exchanger loop should be open all the times independent of the thermostat or??

I wish I had A/C in my garage! Just well insulated to help keep the heat out in the summer and the heat in during our winters. Not that I haven't thought about it tho...

 

[mike_sno]

Getting back to the EWP. If you go electric and install the electric water pump up front by the radiator, you have to remove the Thermostat to allow coolant flow even if the thermostat is closed. This would lead in longer warm up time. Any idea how much that increase?

What to do with the mechanical coolant pump? Will that just be in place and you remove the chain to drive it or can it be gutted to allow easier water flow?

I'm thinking if the mechanic water pump deletion gives you let's say 5hp more and the efficiency of the mechanics is 50% we're talking about a 2.5Hp water pump roughly 2kw. I replace that with a 12V 10A pump which is around 0.12kw is an electric water pump strong enough? Knowing that the lines to the front are also longer?

 

[Ross]

The Davies Craig electric water pump controller has its own thermocouple sensor, and when the engine is cold, it only runs the pump in occasional short bursts. As the temperature increases, it increases the duty cycle of the water pump. So the warm up time shouldn't be much different than a stock thermostat with some small holes drilled in it.

Some builders just leave the stock coolant pump, with the chain removed. Others have cut the fins off the aluminum impeller, again removing the chain drive.

According to my search engine:
"A conventional water pump can consume approximately 15 horsepower between 6000 and 7000 RPM. In contrast, an electric water pump typically draws a maximum of 15 amps, which equates to about 1/3 horsepower."