wat does the water pump do....

When the thermostat is closed, is it just pushing water against the closed thermostat to keep the pressure up? seems like this would lead me to think that having an electric water pump would free up more than just parasitic loss from the beltpower. Any ideas on this?

It circulates the water the same, it just bypasses the radiator so your engine warms up faster, but not uncontrollably faster. :)

mechanical water pumps do hold back your engine and electric pump allow you to put those horses to better use but to put one in an every day driver would put extra wear on the charging system costing more money than usual-that is after initial upgrade to run pump(electric pumps are also not made to run constantly so they will burn out faster too)

circulates water/coolant thats already in the engine. just like how the coolant bypasses the heaters when the heat is off. electric water pump is not a good mod imo. alot more stress on charging system and only see a 4hp improvement in . plus they cost over 450.00. http://www.gmhightechperformance.com/tech/0411htp_ls1_aftermarket_maf_sensor_water_pump_test/photo_33.html

circulates water/coolant thats already in the engine. just like how the coolant bypasses the heaters when the heat is off. electric water pump is not a good mod imo. alot more stress on charging system and only see a 4hp improvement in . plus they cost over 450.00. http://www.gmhightechperformance.com/tech/0411htp_ls1_aftermarket_maf_sensor_water_pump_test/photo_33.html

Actually been quite happy with the results of running an electric pump as the car seems to run cooler overall and expecially if caught in traffic. I'm cheating some as the car is a C4 but they are known to run quite hot as a rule of thumb. With a 160 thermo and decent weather, the car never goes over 171 degrees and usually idles in the 165-168 range in 80 degree heat w/o the air on. This is with a .040 over block, 398ci and almost 13 to 1 compression. Sure I've got a dyno sheet lying around somewhere showing a small gain, but I'd run one again in a heartbeat just for the cooler temps.

If you believe the mfg spec's, you've got to do whole lot of driving to wear one out.

I have a 383 LT1 with an electric WP in my daily driver. Car runs pretty cool.

I have a 383 LT1 with an electric WP in my daily driver. Car runs pretty cool.

Somehow based upon where you live, that is very believeable to me. I'd be more concerned on how to get one to warm up vs cool down. Damn, it's gotta get cold up there in the winter. Whew...

Somehow based upon where you live, that is very believeable to me. I'd be more concerned on how to get one to warm up vs cool down. Damn, it's gotta get cold up there in the winter. Whew...

Its a summer car only and it gets up to about 100 F here in July/August.

alot more stress on charging system and only see a 4hp improvement in.

How does it put more stress?

so while the thermostat is closed all the water in the block is being moved by the wheel of the waterpump? which is driven by ur cam/ timing chain, so wouldnt getting an ewp also help with revs, or is this another one of those it will help but not enough for the price tag kinda of things?

after looking at the graph it almost seems worth it, it might only make 4 more hp at peak, but it defintly adds to the whole curve, wich is what its all about right? when i have some extra money i think ill get an ewp. IMO its worth it

after looking at the graph it almost seems worth it, it might only make 4 more hp at peak, but it defintly adds to the whole curve, wich is what its all about right? when i have some extra money i think ill get an ewp. IMO its worth it

One of those whom believes a bunch of little things adds up in the end and any time you can find something that helps, I jump on it.

That is a lot of money for the power gained, ignoring the other maladies that will come with having an electric water pump. I guess this is where the bolt-on idealists enter?

I would put the money towards a set of coated bearings—that too many people skimp on with an endurance engine like a daily driver—for a future rebuild or a dyno tune.

One of those whom believes a bunch of little things adds up in the end and any time you can find something that helps, I jump on it.
yea im one of those guys, but im also one of those guys who has a forged 383 with le heads/cam under his hood

That is a lot of money for the power gained, ignoring the other maladies that will come with having an electric water pump. I guess this is where the bolt-on idealists enter?

I would put the money towards a set of coated bearings—that too many people skimp on with an endurance engine like a daily driver—for a future rebuild or a dyno tune.

When I said little things can add up.......I meant ALL the little things. Below was a sign for the car competing at the O'Reilly AutoRama. (Best in Class btw) On top of that everything must be working perfectly. Any time I can find a 4 hp gain, got a grin on my face. Thinking about a new cam right now even.

Engine and Tuning: Scott Whitehorn - A&S Automotive, Keller Texas

Blueprinted 12.8 to 1 compression, 398ci splayed LT4 block with thermo and friction coatings, 8 quart DRM oil pan, Eagle 3.875 forged crank, Howard's powder forged lightweight 6" rods, Lunati gas ported custom lightweight pistons with J&E rings, Custom Comp Cams camshaft, 1.65 Pro Mag rockers with Morel lifters, Titanium retainers and PSI springs, Ram Air induction, 1200cfm Arizona Speed & Marine billet throttle body, Billet MAF, 42lb SVO injectors and Aeromotive adjustable fuel pressure regulator, Walbro 255 LPH fuel pump. Tuned using LT1.edit software.

Sheetmetal Intake: Jeb Burnett, Little Rock AR

Heads: Trevor Johnson Cylinder Heads/Lloyd Elliott, Rockwall/Red Oak TX

23 degree Trick Flow aluminum heads with 2.08/1.625 valves and thermo coatings

Exhaust:

Hand-built 1 3/4th stepped to 1 7/8ths coated headers with tapered merge collectors, Self locking header bolts, Hand-built dual 3" exhaust with X-pipe and DynoMax mufflers

Ignition:

Delteg Multi-coil Optispark replacement

Cooling:

Be Cool HD radiator, Meziere HD electric pump with 160 degree thermo

Drive Train and Suspension:

ZF 6 speed transmission with (HD Dodge Viper) 4:11 gears in a Dana 44 rear-end, Dual Mass flywheel with HD pressure plate and ceramic disk clutch, Z-51 suspension with Bilstein gas shocks and Doug Rippie MotorSports relocating arms

Paint:

Sebring Silver base with six coats of clear by owner.

Dual Mass flywheel with HD pressure plate and ceramic disk clutch


Any particular reason you are using a dual mass flywheel? (no standard flywheel/torsion disc?) Those things are heavy and have huge inertia.

Any particular reason you are using a dual mass flywheel? (no standard flywheel/torsion disc?) Those things are heavy and have huge inertia.So, it's not just a clever name then.;) I don't think that's his car, so he probably can't answer that in any case.

Back on topic- on the matter of coolant recirc- I know the LT1s do that, but how about the LSx? I"m not up to speed on that. The older small blocks dead-head against the Tstat until it gets hot enough, so you have very little flow until the Tstat opens.

And for me, I'd spend $300 on the things that net more than 4hp first, before I got to that. Plus, electric pumps make me nervous- probably unfounded, but it seems like added complexity for little gain.

And for me, I'd spend $300 on the things that net more than 4hp first, before I got to that. Plus, electric pumps make me nervous- probably unfounded, but it seems like added complexity for little gain.

Electric water pumps made me nervous at first but I don't think twice about it now as so far, the two I've owned have been quite reliable. No....it wouldn't be my first choice for doing mods, but you can only do so much until you run out of things to do. Same for the friction and thermo coatings.

Any particular reason you are using a dual mass flywheel? (no standard flywheel/torsion disc?) Those things are heavy and have huge inertia.

Cheat just a tiny bit as after my SS was stolen, I bought a Collectors Edition LT4 C4. Was very comfortable with the LTx technology vs LSx technology. That may have been short sided thinking.

The transmission is different vs an F-body and if you use a lighter single mass flywheel the trans rattles in neutral. Just getting old n cranky not caring for the noise having two billet flywheel assemblies sitting in my garage set and ready to bolt in if needed. Plus I hear all about hp gains from aluminum driveshafts and lighter flywheels, but so far I’ve not seen them on the dyno.

Cheat just a tiny bit as after my SS was stolen, I bought a Collectors Edition LT4 C4. Was very comfortable with the LTx technology vs LSx technology. That may have been short sided thinking.

The transmission is different vs an F-body and if you use a lighter single mass flywheel the trans rattles in neutral. Just getting old n cranky not caring for the noise having two billet flywheel assemblies sitting in my garage set and ready to bolt in if needed. Plus I hear all about hp gains from aluminum driveshafts and lighter flywheels, but so far I’ve not seen them on the dyno.

Ya I know the transmissions are different, I guess they never made a single flywheel with a traditional disc that has the damper vs. the flywheel. Since it rattles there is no damper in the disc then.

I know a good amount about most 'Vette manual setups since I used to work for the company that made the stock clutch/disc's, more familiar with LT1/4/5 and LS1/2/7 setups. I was never able to info for the ZF trans if they made a traditional style setup. I know they only offered a dual mass setup for the LT5, so I guess more than likely no traditional setup was made fro ZF.

If you think those are big and heavy you should see the ones for the diesel truck they make, holy crap they are like 100 lbs.:eek:

I know the feeling, I can't stand the rattle in my car. I know it needs a new disc for sure.:mad:

Ya I know the transmissions are different, I guess they never made a single flywheel with a traditional disc that has the damper vs. the flywheel. Since it rattles there is no damper in the disc then.

I know a good amount about most 'Vette manual setups since I used to work for the company that made the stock clutch/disc's, more familiar with LT1/4/5 and LS1/2/7 setups. I was never able to info for the ZF trans if they made a traditional style setup. I know they only offered a dual mass setup for the LT5, so I guess more than likely no traditional setup was made fro ZF.

If you think those are big and heavy you should see the ones for the diesel truck they make, holy crap they are like 100 lbs.:eek:

I know the feeling, I can't stand the rattle in my car. I know it needs a new disc for sure.:mad:

They still rattle even with a sprung disc when using a single mass. It's the nature of the beast due to the main shaft/ counter shaft spacing, or something like that. Also means they're stronger the most. Very reliable tranny and much under rated. Expensive to repair/rebuild as well.
Scott

but you can only do so much until you run out of things to do.I usually run out of money before I run out of things to do like $300 water pumps.:D

My T56 rattles a little in neutral- always has since I bought it new in crate. I'm running a factory LT1 clutch and a 35lb billet flywheel (that's all there was in 1995:) ).

I think the less mass thing helps a lot more in the lower gears. If you're running a dyno at 250rpm/sec accel rate, it won't show like it would at 600+rpm/sec. Driveshaft mass is so close to center, that it doesn't add much inertial load, so the benefit is minimal. Of course, that didn't stop me from spending $150 on a 5.0 aluminum shaft, just to see if it would work.:lol: Fit like a glove.

I think the less mass thing helps a lot more in the lower gears. If you're running a dyno at 250rpm/sec accel rate, it won't show like it would at 600+rpm/sec. Driveshaft mass is so close to center, that it doesn't add much inertial load, so the benefit is minimal. Of course, that didn't stop me from spending $150 on a 5.0 aluminum shaft, just to see if it would work.:lol: Fit like a glove.

The drive shaft may not have a large radius for inertia, you have to remember it is much longer than a flywheel and all of its mass is contained at the outer radius. Where as a flywheel will have more evenly distributed mass, WRT radius and its mass is more close to its center. What are typical weights for flywheels and driveshafts? Then we could figure out easily what has more inertia.

Actually I think less inertia helps in higher gears where your mechanical advantage is smaller than in lower gears. Lower gears = more torque.

The bigger reason though not to get an aluminum driveshaft is that farther away from the engine, inertia has less effect on torque/rpm acceleration. The easiest way to see it it that the farther away from the engine you have mechanical advantages (i.e. trans gear ratio, differential gear ratio, and then tire/wheel sizes). Although if you are looking for overall weight reduction, then every little bit helps.

They still rattle even with a sprung disc when using a single mass. It's the nature of the beast due to the main shaft/ counter shaft spacing, or something like that. Also means they're stronger the most. Very reliable tranny and much under rated. Expensive to repair/rebuild as well.
Scott

Thats what seems to be the norm around here, although OEM replacements are junk compared to OEM originals. OEM originals take out all gear rattle in operating RPM's, or else people at FORD, GM, etc. really get mad.:o

I think the less mass thing helps a lot more in the lower gears. If you're running a dyno at 250rpm/sec accel rate, it won't show like it would at 600+rpm/sec. Driveshaft mass is so close to center, that it doesn't add much inertial load, so the benefit is minimal. Of course, that didn't stop me from spending $150 on a 5.0 aluminum shaft, just to see if it would work.:lol: Fit like a glove.

Had my 97 SS dealer fitted with the optional aluminum driveshaft vs the steel one and immediately went to the dyno and got zero gain. In swaping from a single mass flywheel back to the dual mass in my C4 there was zero loss on the dyno in going to the heavier one.

One of those who thinks you really have to watch and deep think about what ya read as hey I read stuff to, but then put it to the test under independent controlled conditions to verify the results. There are a bunch of scammers out there trying to get your money in my opinion. Was really bummed about the driveshaft, hopeing to pick up 3-5 hp from what I was reading. Man, I was hyped!!

Had my 97 SS dealer fitted with the optional aluminum driveshaft vs the steel one and immediately went to the dyno and got zero gain. In swaping from a single mass flywheel back to the dual mass in my C4 there was zero loss on the dyno in going to the heavier one.

Wow, I would expect to see a difference.

On our bike engine at school took out 2 gears and shaved down 2 others and saw an average of 2%-5% increase across the torque curve with a peak around 12%. Maybe the loading dyno has an effect?

I can't figure out what I'm missing.

Back on topic- on the matter of coolant recirc- I know the LT1s do that, but how about the LSx? I"m not up to speed on that. The older small blocks dead-head against the Tstat until it gets hot enough, so you have very little flow until the Tstat opens.

Don't forget about the heater hose lines- they are quite often the way of recirculating the coolant through the engine prior to the thermostat opening.

The drive shaft may not have a large radius for inertia, you have to remember it is much longer than a flywheel and all of its mass is contained at the outer radius. Where as a flywheel will have more evenly distributed mass, WRT radius and its mass is more close to its center. What are typical weights for flywheels and driveshafts? Then we could figure out easily what has more inertia.It's likely the opposite. I know that for my car, the stock 2.75" steel shaft was about 16lbs, whereas the 3.5" aluminum one was just over 8, IIRC (I have notes, but not on me). On my flywheel, the majority of its mass is far from center, not close. If I had to give a percentage, I'd say that 65-70% of a flywheel's mass is out in the area of the clutch disc surface. To me, there's no question that a flywheel puts a far greater inertial load on the engine than the driveshaft, due to the distance of the mass from the rotational center.
Had my 97 SS dealer fitted with the optional aluminum driveshaft vs the steel one and immediately went to the dyno and got zero gain. In swaping from a single mass flywheel back to the dual mass in my C4 there was zero loss on the dyno in going to the heavier one.That doesn't surprise me, especially with a 4th gear pull. If you pulled again in 2nd gear with the two weights, I'd expect to see something- probably not huge, but something. Inertial loads matter more the faster you try to spin the engine up.

Unfortunately, I've forgotten how to calculate all this.:D

Surely, some of the big boys here that do dyno work have experience with this?

[QUOTE=Todd80Z28;4564638].
That doesn't surprise me, especially with a 4th gear pull. If you pulled again in 2nd gear with the two weights, I'd expect to see something- probably not huge, but something. Inertial loads matter more the faster you try to spin the engine up.

QUOTE]

Common sense says a lighter weight will be easier to rotate and what you’re saying makes sense. Being nothing shows up on the dyno in 4th gear, I'd also believe it would be minimal at best in lower gears but some consequence should be evident. However there is also a stored energy effect that may make a car actually quicker upon launch and changing gears. For both reasons a heavier flywheel doesn’t bother me but I don’t have objective track data to substantiate that statement. My launch rpm’s did change with different flywheels, but not sure if the car went slower, faster or to check the box that says: None of the above.

My issue is and always has been being I'm a consumer, aftermarket companies promoting false gains with conjured or irreproducible data. At least with the water pump you see reproducible gains pretty much across the board.

Plus if you believe David Vizard, the ideal temperature for making hp is 170 degrees. With a 160 thermo, the fans programmed to come on just over 160 degrees and the electric pump, my personal car stays pretty close to 170 most of the time. Even after a hard run in 70-80 degree ambient temperatures it rarely goes over 176-178 and then recovers quite quickly.

My sheetmetal intake with a substantial air gap may be helping some plus the car has an enlarged air intake, but I'll take anything you can get. Two thumbs up for electric pumps in my movie rating.

Don't forget about the heater hose lines- they are quite often the way of recirculating the coolant through the engine prior to the thermostat opening.

Not normally, unless its a truck with the heater return back to the radiator tank itself. Normally the heater hose plumbs back into the coolant crossover jacket which then routes the coolant through the thermostat and out the waterneck.

SBC's have a coolant bypass on the passenger side water pump leg that recirculates the coolant back into the block until the thermostat opens.

Common sense says a lighter weight will be easier to rotate and what you’re saying makes sense.

But this isn't true, mount a 2" diameter tube that weighs 2lbs and a 10" diameter tube that weighs 2lbs and see what is harder to spin.

Basically inertia is based on some percentage of weight and the square of the radius for round items spining about their own axis

Example:
Inertia of tube about its own axis = mass * radius^2


So, for an equivalent mass making the radius larger makes it hard to turn, a la inertia.

To me, there's no question that a flywheel puts a far greater inertial load on the engine than the driveshaft, due to the distance of the mass from the rotational center.
That doesn't surprise me, especially with a 4th gear pull. If you pulled again in 2nd gear with the two weights, I'd expect to see something- probably not huge, but something. Inertial loads matter more the faster you try to spin the engine up.

Right, Torque = Inertia*rotational accerleration

But not only for distance from rotational center but also due to gearing in the transmission. You have effectively increased your torque (say 2.5 times roughly for first gear) where as you only reduce your weight by 0.5 times. I think its safe to say gearing has more bearing on the inertia in the driveshaft/axles than the inertia.

Not normally, unless its a truck with the heater return back to the radiator tank itself. Normally the heater hose plumbs back into the coolant crossover jacket which then routes the coolant through the thermostat and out the waterneck.

SBC's have a coolant bypass on the passenger side water pump leg that recirculates the coolant back into the block until the thermostat opens.


Not sure what small blocks you've been working on, but on every (Gen1) small block I've worked on the hot water comes FROM the coolant crossover in the intake, through the heater core lines and returns TO the rad or the water pump (doesn't matter which- either one is on the suction side of the pump), creating a complete recirculation path for the coolant when the stat is closed.

The second part I'll agree with, but that passage is TINY. Maybe 1/4" at the most. It won't flow anything like the heater lines will.