My little project, VH in an HR31 Skyline coupe

[Mettler]

Hey guys, I've had this project on the go for a number of years... it's now nearly finished, so I thought I'd share it with you!

I've finished off most of the engine build that I started over 2 years ago hahaha

I've used brand new head bolts, rod bolts, bearings, rings, cam cap bolts, gaskets etc... everything in the engine has been either replaced or freshened up.

Most of the internal parts I've used like chains, cams, sprockets, lifters, finger rockers etc have come out of a very low km donor VH41DE I scored for 500 bucks. It used to be used in a boat, except they used steel exhaust manifolds that caused electrolysis corrosion on the exhaust ports (as seen in my build thread), hence a bunch of new condition parts for my stroker motor... woot!

I'm using a VH45DE crankshaft and pistons which have been checked and prepped by the engine reconditioner and myself, the VH41DE rods are identical so I'm using the ones from the above donor engine.

Block has been acid dipped, bores honed, everything checked, and deck surface machined down by about 0.3mm.

Heads have been ported & polished, multi angle valve job, upgraded valvesprings installed (ready for when I cam it), and surface machined down a bit.. not sure how much. Between that and the deck machining, I should see a small increase in compression ratio

I started at around 7pm two days ago, and didn't stop working on it for about 17 hours straight... stayed up all night, bled all the HLAs etc. This motor's gonna run mint, it's so tight to spin!

Here's the full build thread for anyone interested in seeing my progress over the last 3-4 years.

Pics are pretty self explanatory, enjoy!

[Mettler]

post more later, bbl

[AZhitman]

Shaun, you're a maniac.

[CrazyTrance]

Oh man, this is interesting for sure!

[tmorgan4]

[Mettler]

Haha sorry about that, I hit post on the thread before linking all the pics, then suddenly had to take off in a hurry to see the stockcar racing qualifying night. Was pretty exciting too, gonna put some vids up later.

Anyway, here are the rest of the build pics:

[Mettler]

And here are some pics off my phone, because we all love looking at VH pics! They look so tough with all that ribbing in the casting!







And some pics of the undressed Y32 VH41DE longblock assembly, showing the main bearing girdle etc:

[Mettler]

Shaun, you're a maniac.

Haha, just a little touch of V8 madness I think

[CrazyTrance]

If you're coffee mug was replaced with a shot glass and some captain morgan, and your leg was raised like standing on a barrel it would be a perfect captain advertisement lol.

[Bart]

Great job MettlerThe VH's look great naked.Hope to do this myself in the future.

[Mettler]

Check out the maze of s*** under the manifold:



And finally, the beast is together!

[justinedible4]

Beautiful.

[hannibal]

In the pic above, youre installing the camshaft. I read youre supposed to start in the middle then work your way out when you torque them down. Did you so this? Not being critical, just curious.

And a total noob question: On the crank where two rods attach, does anything sit between the rods or do they touch? I saw in an SR build something called thrust washers on the crank, but couldnt tell how exactly they were installed. On a V8, are the thrust washers between the rods on a shared crank throw?

[Mettler]

In the pic above, youre installing the camshaft. I read youre supposed to start in the middle then work your way out when you torque them down. Did you so this? Not being critical, just curious.

Nah I started at the front and worked my way along, but only gradually did each one up in stages so I could torque the caps down evenly. Would not have easily been able to start in the middle.

And a total noob question: On the crank where two rods attach, does anything sit between the rods or do they touch? I saw in an SR build something called thrust washers on the crank, but couldnt tell how exactly they were installed. On a V8, are the thrust washers between the rods on a shared crank throw?

Nothing sits between the rods, they're both floating on a shared journal. This does not become a problem because of all the oil everywhere.

Look at the middle journal of the crankcase in the following pic, and you will note the additional machining on the front (and rear) faces. The thrust washers fit in there before you drop the crank in, and another two thrust washers fit into the cap.



Thrust washers pictured top left:

[Mettler]

Stock combustion chamber volume = 61062.3425 cubic millimeters

Heads planed 0.25mm.

Milled Volume = 1467.0155 cubic millimeters (removed from combustion chamber)

0.3mm milled off block deck. Pistons sit proud of deck by 0.3mm

Revised swept volume = 559735.6781 cubic millimeters

Proud Volume = 2037.8726 cubic millimeters

61062.3425- 1467.0155- 2037.8726

Revised chamber volume = 57557.4544 cubic millimeters

559735.6781/57557.4544 + 1 = 10.7248

Revised compression ratio = 10.72:1

Unless I am mistaken and the swept volume includes the volume of the piston's protrusion above the block deck.... which would put it at 10.76:1

I'm not complaining, unless valves and pistons start banging heads.

Woot! Now to calculate DCR...

The swept volume at 48 degrees ABDC = 488860.1132 cubic millimeters

488860.1132 / 57557.4544 = 8.49:1 dynamic compression ratio!!

That's a massive 0.45 increase over the stock 8.039:1 DCR during advance.

Lets hope I don't run into any problems.

[maxnix]

So I guess the non US VH41DE have the crank girdle also like the VH45DE?

[kingkilburn]

The only differences are the crank, timing gear, and location of accessories on the front.

[Mettler]

So I guess the non US VH41DE have the crank girdle also like the VH45DE?

Yeah the Y32 VH41DE has the girdle, this has been confirmed for years!

[DORIFUTO_The Future]

Damn man, nice work. When ever the search for a vh41 becomes to hard I just look at one of yours or gsracers threads and it all seems worth it!

[Mettler]

Haha cheers man, I hope you find one soon!

Ok I've had another look at the calculations I did earlier and realised I'd based them on VH45 cam specs. I revised things a little and redrew my cam profile to match VH41 specs as per the diagram in the Y33 service manual. My motor's a Y32 version, so I'm not 100% certain the profiles are the same, but it's good enough for the purposes of collision detection.

Unless I am mistaken and the swept volume includes the volume of the piston's protrusion above the block deck.... which would put it at 10.76:1

I was mistaken, and it is 10.76:1

Now check this out:According to that image from the Y33 Factory Service Manual, the intake valve opens at C, 5 degrees BTDC. It then remains open for a full 180 degrees, and then a further 57 degrees according to D.

Science and maths tells me this adds up to 242, yet the stated intake duration value B states 232. Stupid ****ing numbers don't add up, shot Nissan, _b, way to print a sweet manual.

Anyway, for my calculations I've decided to go from the valve opening point of 5 degrees BTDC which is the earliest possible opening point that can be interpreted from these nonsense specs, and use the stated duration of 232 degrees.

Using this method, I've established there will be no piston to valve collisions with the intake cam, despite the cam being for a VH41 and also despite the machining of the block and heads. At 3.2 degrees ATDC it does get pretty close however:



Furthermore, with an intake valve closing point of 27 degrees ABDC when the cam is advanced by VTC, the remaining swept volume of piston travel is 539334.6063 cubic millimeters:

So divide this swept volume at intake valve closure by the revised combustion chamber volume to get the revised dynamic compression ratio for my specific engine:

539334.6063 / 57557.4544 = 9.37

So my new dynamic compression ratio under cam advance is 9.37:1. Dammit, that's way too high for safe operation. The stock VH41DE dynamic compression ratio under cam advance is only 8.1:1!

My motor is definitely going to need longer duration intake cams in it now.

Hmmm... if I disabled VTC...

:edit: lol fark! Even with VTC disabled and the cam retarded 10 degrees (20 degrees of valve timing), I still get 8.58:1 dynamic compression ratio. This 'may' work if I run my engine on 98 high octane pump gas all the time, but ffs, that's bodgy as and far from optimal! >_<

I will be referring to several articles including this one to design the new cam profiles for my motor.

[hannibal]

Thanks for the explanation and pics Mettler! I'm guessing the two smooth washers fit on the block and the washers with tabs fit in the cap.

Looking at that FSM page, I think the c=57 is a typo. On the exhaust side f=47 and that adds up to 232 and c and f look about the same distance from BDC.

[Mettler]

URRRGHH

My modified aluminium sump turned to s***. Welding warped it and shrunk it in the middle so the holes don't line up properly anymore. Dammit! Lol, lesson learned.

Designing a custom steel sump now, expanded volume, trapdoors & all... the works.

Getting there slowly. Designing it so that it's actually constructable from multiple pieces as well as able to be folded out into a pattern has needed a bit of messing around.

From here:

To this:

To an almost complete redesign. The yellow box represents the interference boundaries I have to work in:









Nearly ready to get bits cut... just gotta add a few more details and it's mint!

[CrazyTrance]

Whats funny is that's essentially EXACTLY what mine looks like now lol. But i'm only half way there. have to finish fabing it. Been messing around with how it's designed and what not. Havent had a chance to run it up in solid works though yet.

Also, does the bottom of your sump sit level with the flange or level with the inlet on the pickup tube? I noticed that my pickup tube does not sit level with the angle of the flange/block. It looked to be at a slight angle, unless i looked at it wrong. Wish i took pictures of it.

[LEMHEAD16]

how much $ did solid works run you guys?

[CrazyTrance]

how much $ did solid works run you guys?

Well i have a student version so i get it for free kind of... it's in the cost of our tuition to use it. I just have to be connected to the school network. VPN works amazing for that.

[Mettler]

Also, does the bottom of your sump sit level with the flange or level with the inlet on the pickup tube? I noticed that my pickup tube does not sit level with the angle of the flange/block. It looked to be at a slight angle, unless i looked at it wrong. Wish i took pictures of it.

Neither, I've just dimensioned off the factory sump to achieve the same slope. It's a little deeper at the front than it is at the back, around 5mm or so.

[CrazyTrance]

Neither, I've just dimensioned off the factory sump to achieve the same slope. It's a little deeper at the front than it is at the back, around 5mm or so.

Good deal, pretty much what i was trying to get at. Thanks