Paging Doctors gs14racer and T45

[z1 zonly]

gs14racer, some questions:

1) Why did you decide to go with the factory water pump setup after fabbing the block-off plate with fitting for an electric water pump? After rereading your post it seems you may have done it to have something for the belt to ride on to make your tensioner setup work. Was this the case?

2) How did your rod knock start (if you know at all)? Very curious to know if it was due to the nature of the VH (oil starvation during cornering?) or some other problem with your actual engine.

3) Why did you get bored/burnt out on the swap? It seems counterintuitive to switch back to an SR after the ordeal to put in the VH. You expressed a liking of the LS1 because it was lighter than the VH--did the car feel nose-heavy or something?

T45--Question:

Got my VG and VH oil pans off and put them side-by-side, and even with some fab experience it's looking like a helluva job. Do you have any more pics of your setup than this?

Oh, and what radiator are you running?

[Bart]

I chopped off the entire bottom of my sump and fabricated the bottom half, if i did it again i would fabricate the entire sump as weldin to the factory alloy sump was a bit difficult, i had it TIG welded.It has an external pick up.

[z1 zonly]

Wow, that's pretty hardcore! Is that a VH41 aluminum sump, though? It's easy to make very nice MIG welds on the Z/VH stamped steel pans.

[Bart]

Yep, its a VH41 aluminum sump.Steel sumps are fine

[z1 zonly]

Any more pics of the VH in your avatar? Looks hot.

[Bart]

Nah I dont, that pic was out of a magazine a few years back, a bloke here was/is using it in his 240Z drag car, full tube chassis etc, hes a chassis builder for drag cars. His name is Adam Clarke, dont know how far he got with it but looked awesome when i saw it in 2002

[T45]

I think that's the only pic I have of the pan. I basically cut the flange off leaving about 3/8" of metal and built off of that. The rear was swapped to the front and the black parts are the Z pan. It was time consuming but it wasn't that hard. You'll need to add some small pieces to get the thing to come together and bend a few pieces but it turned out pretty good.

I'm running the stock NA Z rad right now. I haven't got the funds to add a better one so it will have to do. I figure it's good for cruising since it did cool a cast iron V6 so it should handle the alum VH well enough until I can get a beeger one.

[David Steele]

Electric water pumps aren't high flow if you compared to high flow aftermarket mechanical water pumps and a mechanical pump actually takes less from the engine.

[z1 zonly]

T45--that's just what I needed to hear (aside from not having more pics, lol). Thanks very much, I hope to have a positive result to show you in the near future.

[Ezekial]

Electric water pumps aren't high flow if you compared to high flow aftermarket mechanical water pumps and a mechanical pump actually takes less from the engine.

I'm dying to hear this explanation ...

[elwesso]

From what I understand you cant really cavatate an electric water pump, plus you can have it run when the motor is off to help cool it down... Helps mainly for high RPM setups from what I understand or if you have to underdrive the pulley hardcore.

Could be wrong, I wont have that intense of a setup for a while.

[SuperHatch]

I'm dying to hear this explanation ...

I'm with you on that one!

Where've you been man? Havn't seen you posting here in a while. Hows the S12?

[Ezekial]

There should be a PM function on this board but yeh ...

Been busy holidaying and working ...

Got offered money for the S12 rolling shell ... dont know why ... so i sold it ... kept the engine setup ...

A good mate of mine "wants" to buy the setup IF he can sort some mounts for an S14 ... otherwise it will sit in my garage ...

[SuperHatch]

There should be a PM function on this board but yeh ...

Been busy holidaying and working ...

Got offered money for the S12 rolling shell ... dont know why ... so i sold it ... kept the engine setup ...

A good mate of mine "wants" to buy the setup IF he can sort some mounts for an S14 ... otherwise it will sit in my garage ...

Gotcha, I'm sorry to hear your project has gone south... keep in touch though, you've always had a wealth of information to share.

[z1 zonly]

T45-- My Dad had a valid question--why can't you just turn the VH's sump 180degrees on its flange?

[SuperHatch]

T45-- My Dad had a valid question--why can't you just turn the VH's sump 180degrees on its flange?

The flange is not symmetrical. There is a bulge in one section towards the front of the pan on the oil pump side of the motor.

Also, you can't juist cut the flange off and switch it while patching the gap created from the bulge in the flange. The sump is simply too large on the VH to fit behind the Z's crossmember.

[T45]

SuperHatchBack is correct. This was my first thought but I only wanted to drop the engine in one time. I wanted a 100% fit without drama and this worked perfectly! You won't get a VH any lower unless you mod the xmember. I only have maybe 1/4" sticking out of the hood. I'll get some good pics soon of everything so it will make it a lil easier to understand how tight everything is in the bay.

And on the dad part....lol....my dad came up to me everyday and told me what he used to do back in the day and tried to give some ideas but his info was a little outdated. He was used to carbs and stuff. He told me how he used to pull engines with an old swingset and rope. lmao He knows his stuff but when it comes to fuel injection he just can't hang. He knows the basic principles but the wiring gives him problems.

I like to think of the VH swap in the Z as the new age muscle cars. To hell with small blocks, they're unefficient and just ugly, and you can buy a VH for next to nothing. I've said it before that if you want big power you need to look elsewhere unless you have tons of custom experience and a big wallet. But if you want the most technically advanced, smoothest running engine of it's time in the best import car of it's time then this is it. I have about $4k in my build and that includes rebuilding the suspension and drivetrain and interior. When I'm done I'll be competitive with most $40-80k sports cars, and not just in a straight line...

[z1 zonly]

The flange is not symmetrical. There is a bulge in one section towards the front of the pan on the oil pump side of the motor..

HAHA! Yeah, that looks elementary compared to grafting the Z32 sump on. Guess I'll still be doing just that, though.

Thanks for the info guys. Every little bit is great.

[T45]

Yeah it took me about 2 weeks working on it at night. But hey, I can say that I built it and it was very cheap, just cost gas and wire.

And it would help TREMENDOUSLY to bolt the VH pan to a nice thick piece of steel before doing any mods. This part I did not do and when I was done the heat warpage ****ed me pretty bad. Even though I moved from spot to spot I still had to BFH it to get it to fit and will eventually build another one that seals better. I has drips...

[z1 zonly]

You mean the flange warped?! When welding, were you leaving the trigger pulled, or were you doing an endless series of tacks? I find the latter works very well for oil pans--doesn't get it hot enough to warp but still makes a strong weld that seals well.

[T45]

I did a thousand small tacks but it still pulled the flange because I didn't grind the edges down either and the thin metal at the edge would burn off quickly and then pull the other piece towards it. I just had it screwed down to some wood and it just turned out like ****. I would like to have taken my time but at the moment the city was on my *** to get the car out of my driveway and I had the twins on the way so I rushed it.

[Bart]

Basically what i did is bolted the sump onto the block, quite easy, then had it tig welded, it did warp a little but i think that was due to the welder not bolting it down properly.Another sump i had done on an RB30T, it is mild steel had it made the same way, and it didnt warp as the fabricator bolted it all down properly.

[T45]

I would have loved to bolt it to the block but with a mig and a freshly rebuilt engine that was out of the question. Oh, and daddy didn't have tig money either so that kinda narrowed down my choices. lol

[David Steele]

I'm dying to hear this explanation ...

Are you dead yet ?

I'm with you on that one!

You gonna die with him?

Eliminating parasitic power loss is untrue in a street car that uses an alternator. The power has to come from somewhere and thatsomewhere is the alternator. In reality, electric pumps have more parasitic power loss for a given flow rate and I will explain why.

Mechanical energy drives the pump; this can be taken right off the crankwith a belt as is done with a mechanical pump. In the case of an electric pump, the power comes from the alternator, which is driven from the crank.Rather than the crank directly driving the pump, the mechanical energy is changed into electrical energy by the alternator, then the electric motor on the pump changes it back into mechanical energy to turn the pump.

Since electric motors and alternator are not 100% efficient, power is lost in this process. So why do we see a little more power when switching to an electric pump when they are less efficient? The answer is simple; they do not pump as much. The average electric pump flows under 35gph, where the average mechanical pump flows twice as much.

-GAR

[T45]

Sorry but I disagree. As for nothing being 100% efficent you are correct but there is a flaw in your theory.

The resultant power increase comes not only from a lower flow rate from the pump, but rather the fact that you are eliminating the drive belt, which is a major power robber in engines and accesories, let alone the actual pumps and alternators themselves.

[SuperHatch]

David, first... and I am certainly not the first person to point this out to you... You're an arrogant ***, and I mean that in the nicest way possible. If you stop with the constant belittling attitude you have towards the other members of this forum, you might come to find some people might take an interest in your project and want your input more often. I actually mean all of that in a very constructive way, it will make getting through life a whole lot easier.

With that being said, you'll ignore all my points below, but I'm going to type them anyway:

I never said that an electric water pump flows more, but I was more in line with the argument of it being more efficient.

You're wrong, and I'm wrong... the correct answer is "It depends"

Why does it depend? Simple... what is the application?

Most OEM mechanical water pumps are capable of flowing close to 100GPM if not more at full flow. This flowrate is directly proportional to engine RPM (which I'm sure you know, I'm stating the obvious for others). The blades of OEM pumps are designed to be very efficient at low speeds, and by "low" I mean <4000RPM. That is why so many OEM pumps experience cavitation at higher RPMs, especially above the factory rev limit. They simply weren't designed to operate in that area for prolonged periods if at all. The upside of their designs is that they flow very well at idle and cruise keeping the engine at a very safe operating temperature for the operating conditions it was primarily designed for.

Aftermarket mechanical water pumps, as you mentioned, have revised impeller designs that greatly sacrifice low speed efficiency for the sake of reducing pumping losses at higher speeds while maintaing flow and fighting off cavitation. The downside of these pumps is that they operate very poorly at idle and cruise RPMs and engines operating at those RPMs for prolonged periods of time will often overheat. Does it make them bad per se? No, just bad for a daily driver.

Electric water pumps attempt to give us the best of both worlds. Even though their flowrates are low, most less that 35GPM, their operating speeds are not directly linked to engine RPM. Oftentimes the electric pumps are available with thermal controllers that will very the pumps duty cycle with the engine coolant temperature. This ensures, regardless of RPM, that the electric motor is consuming the minimum amount of energy possible to maintain the optimum cooling. At sustained high RPM use (circle track) they simply can't compete with high efficiency mechanical pumps and the engines generally overheat. The benefit, as mentioned by T45, is that it's not just as simple as removing the mechanical load of the pump and adding the electrical load to the alternator. You are also removing the belt drive load, which can be substantial. Unfortunately, electric pumps don't have the steadfast reliability of mechanical units, and that's also a major downside.

The argument for the electric pump can be made very easily:

What if the engine only needs 35GPM to maintain the desired coolant operating temperature, but you're running the mechanical pump at 80GPM because that's what the mechanical link is driving it to? Surely the mechanical pump is using more energy than the electric pump at 35GPM is demanding of the alternator, therefore you've free'd up power.

The argument for the mechanical pump can be made just as easily:

What if the engine needs 80GPM to maintain it's desired operating temperature, and your electric pump is only providing 35GPM? Obviously the engine would overheat with the electric pump and the mechanical pump is the only choice.

The above reasons are why "It Depends".

On a 100% drag car, or a car that sees very limited street use, I would say run the electric for the last bit of additional horsepower.

For a primarily street car, I would say run the OEM pump.

For an extended high RPM use engine, run a high RPM optimized mechanical pump. Unfortunately that isn't really an option for us VHer's, so we stick with OEM.

[z1 zonly]

WELL, um, hate to interrupt this episode of 'As NICO Turns,' but I'm stoked to tell T45 that my oil pan is mocked up and tacked in place. Pics coming soon--lots of work ahead, but I hope to be done by the end of the week!

I took a different approach by cutting the ENTIRE bottom of the Z32 sump and grafting it to the first inch-or-so of the VH flange.

[T45]

That's a good idea too, post some pics! It may turn out better than mine did. I need to make another one in the very FAR future.

The slimmer you keep the oil pan the lower you can get the engine in the car. I should have made the pan about 1/4" taller and raised the engine up that 1/4" and then the manifolds would have bolted right up. Instead I got the engine so low that the mani's hit the xmember and I had to flatten the xmember a little bit as well as the bottom front halves of the mani's to get that extra 1/4" back.

Just make sure you have the mani's bolted to the engine when dropping it in. It's much easier to get them on and they will fit between the rails and then you also can see what clearance you'll have on the xmember. I just used the stock mani's with all the heat shields removed and the cats cut off. The cats and shields hit everywhere. I can get the headers off by just unbolting the mounts and raising the engine up an inch or two, or dropping the xmember.

[z1 zonly]

Hmm, 1/4" clearance doesn't sound very comforting. With a rubber mounted engine, do you fear that your headers may contact the crossmember over big bumps, drag launches, etc.? If so I may need to look into shimming the mounts out a bit (bad news, I really don't want it to hang out of the hood).

Another thing I was wondering--should I drop the engine in with the hacked-off headers and tack the Z32 flanges into place under the car, then pull the engine back out to weld them up? Is there room to get enough MIG gun in there to fully weld them with the engine in the car? Is there enough clearance that a careful guess might be good enough to go ahead and weld them before dropping the engine in (it will be a custom exhaust, so not worried about mating to the existing Z32 setup)?

Trying to keep test-fitting to a minimum. One shot, one kill baby.

[SuperHatch]

That's a good idea too, post some pics! It may turn out better than mine did. I need to make another one in the very FAR future.

The slimmer you keep the oil pan the lower you can get the engine in the car. I should have made the pan about 1/4" taller and raised the engine up that 1/4" and then the manifolds would have bolted right up. Instead I got the engine so low that the mani's hit the xmember and I had to flatten the xmember a little bit as well as the bottom front halves of the mani's to get that extra 1/4" back.

Just make sure you have the mani's bolted to the engine when dropping it in. It's much easier to get them on and they will fit between the rails and then you also can see what clearance you'll have on the xmember. I just used the stock mani's with all the heat shields removed and the cats cut off. The cats and shields hit everywhere. I can get the headers off by just unbolting the mounts and raising the engine up an inch or two, or dropping the xmember.

Well that answers the question I asked in my thread about the factory manifolds...

Did you ever consider lowering the crossmember to increase hood clearance? I realize it would adversely effect the roll center, but it might be a worthwhile tradeoff.