The Master VH45 detailed spec/measurement/part# thread

Post by **defrag010** » Wed Jun 07, 2006 6:15 pm

So I got bored at work today, and I decided to pop a piston/rod assembly out of a core VH45 and take every measurement known to man. I started to dig into the head, but got busy so there are some things missing on the head.

I started with THIS.

... and ended up with THIS [*URL is dead].

The first thing I'm going to say is that I have read a few threads about people talking about all this twin turbo power on stock internals. Now, from what I found the stock stuff in a VH45 is beefier than most, but there is a physical limitation that nothing but magic can overcome. the stock rods are physically almost the exact same size as a SBC powder rod, and the piston is hypereutectic. I, along with the other engine builders at work, estimated that an optimistic physical limit to the VH45 would be around 75hp per rod, which is about 600 crank horsepower. I don't mean to rain on anyone's parade, but I don't want people to think the VH45 bottom end is something that it's not.

Now, onto the specs. Underlined links are clickable, and link to pictures. Feel free to add to this, but I'd like to keep this thread mostly spec/info and less chit-chat. I will post more measurements of the entire engine whenever I have the time to get them.

* all measurements are +/- .005"

Bottom End

Piston/ringsBore = 3.635" / 92.1mmWristpin = .865" / 22mmCompression height = 1.257" / 32mm1st and 2nd Ring thickness = .074" / 1.88mm / (~5/64")Crown to first ringland distance = .235"First tingland to second ringland distance = .125"Small end gap = .985"

Piston pic 1Piston pic 2Piston pic 3

Rod*bushed small end, with forced pin oiling and a piston oil squirter on rod*Length (center of bigend to center of small end) = 5.8"Big end width = .865"Small end width = .700"Big end bore = 2.160"

Rod pic 1

Head

Intake valve head size = 1.501" / 38.15mm (no oversize possible w/o shrouding)Exhaust valve head size = 1.300" / 33mm (oversize possible)Rocker ratio = 1.6Exhaust camshaft base circle = 1.175"Exhaust camshaft total circle at centerline = 1.392"Exhaust camshaft lobe lift = .217"Exhaust valve lift w/ 1.6 rockers = .347"

Valve stem seals (SBI part numbers, viton, metal clad style)Intake:90-95 = 122-123996 = 122-1264Exhaust:90-96 = 122-1159

That's all for now, check back for more as I update this thread.

Post by **defrag010** » Wed Jun 07, 2006 6:45 pm

With a crank offset -.006" and undersized to 2.100" on the rods, along with an overbore of 94.9 mm, you could use Chevy 305 Forged pistons with Chevy 400 H-beam rods narrowed .075" on the big end for a SICK bottom end capable of some power!

Post by **AZhitman** » Wed Jun 07, 2006 7:15 pm

NICE WORK!

Definitely article-worthy...

Look at this block - WAY overbuilt:

Post by **Mettler** » Wed Jun 07, 2006 7:23 pm

Excellent work ! If somebody could please include these same specs for a Y32 VH41DE that would be awesome, could compare the differences internally that way !

Post by **elwesso** » Thu Jun 08, 2006 4:14 am

Defrag thanks for the pictures..... However, do you think you could email them to me in a ZIP file so in case they go down i can load them onto my website or onto NICO?

I just dont want these pics to be lost, however i suppose the information is more important...

Despite how wimpy the rods look it seems they can really handle some good power... double the HP on a N/A engine isnt too bad..... however the question remains... NIZPRO down in aussie is running close to 1000HP on his stockish VH45 and from what it seems its on the stock bottom end...

Post by **sijoko** » Thu Jun 08, 2006 8:55 am

Thanks for the pictures and measurements.

I noticed that the piston doesn't appear to have any coating on the sides. Has it been removed or did Nissan stop installing coated pistons somewhere along the production timeline of the VH45DE?

Here's a picture of a VH45 piston with the coating.

Post by **defrag010** » Thu Jun 08, 2006 2:02 pm

sijoko, the piston I pulled was out of a core that I do not know the year of. It has siamese intake ports on the heads, and I remember reading something a long time ago about the later VH45's not having siamese intake ports.

What kind of coating is that on the piston in the picture?

elwesso, You've got mail! Again, about the 1000hp thing - what I said is just what I belive an optimistic limit to the motor is based on a few years of building alot of race engines. I'd like for the twin turbo boat guy to come up with some real numbers like I am doing with my measurements so that we won't have to second guess ourselves.

I will be finishing rebuilding one of the heads tomorrow, and I am going to experiment with some VG30 inner valvesprings to see if there is compatibility, along with finding a new style bolt to bolt the cam towers down (HORRIBLE design w/ tiny torx bolts).

Post by **Ezekial** » Thu Jun 08, 2006 2:53 pm

defrag010 wrote:The first thing I'm going to say is that I have read a few threads about people talking about all this twin turbo power on stock internals. Now, from what I found the stock stuff in a VH45 is beefier than most, but there is a physical limitation that nothing but magic can overcome. the stock rods are physically almost the exact same size as a SBC powder rod, and the piston is hypereutectic. I, along with the other engine builders at work, estimated that an optimistic physical limit to the VH45 would be around 75hp per rod, which is about 600 crank horsepower. I don't mean to rain on anyone's parade, but I don't want people to think the VH45 bottom end is something that it's not.

Do me a favour and take a photo of the VH45 conrod vs SR20 conrod.

Are you then going to tell me that an SR20 conrod is also good for 75 crank hp per conrod = 300 hp (because thats when i'll tell you i know of many examples running 400-450 RWHP on standard rods. (500-550 crank hp = 125-137.5 hp / rod)

This is without taking into consideration the fact VH45 is far superior in rod/stroke ratio. ie longer conrod + shorter stroke and of course has a much lower peak piston acceleration and peak piston velocity. aka less stress on conrod

I know my engine will be the test. I believe the conrods are probably closer to 150 crank hp / conrod.

Nizpro's 1000 crank hp VH45DE speed boat is testiment of this.

Good topic though mate!! Keep it up!!

Post by **elwesso** » Thu Jun 08, 2006 4:27 pm

I appreiate defrag being conservative... Id rather have that then be way more optimistic and blow someones sh1t up because of what some guy on the forum said.. I respect his opinion.. We *DO* know theyll be find to 600HP.. more? WE'll find out!

defrag I dont think i got your email send again plz.

Ezek... do you know where he posted about the VH45 being 1000HP?

Post by **Ezekial** » Thu Jun 08, 2006 5:59 pm

I spoke to Simon on the phone

Post by **defrag010** » Thu Jun 08, 2006 6:02 pm

elwesso, I'm sending them right now. I had to create 4 different zip files at 20mb each (the pics are high res, and there are some in there that isn't VH stuff (didn't feel like sorting through them so I just did the whole folder) ). I got caught up earlier, but now I can send them all.

Ezekial, I'm not trying to start a debate about power levels, I'm just giving my honest opinion on a reasonable amount of power to expect from the engine. I'm not saying 1000hp isn't possible, but we know nothing about this guy's twin turbo setup along with his claim. I've never heard or seen an engine with hypereutectic pistons and I-beam rods (you can only get so much from this type of design) make that kind of power, and other engines of the same design (Hypereutectic/I-beam/alum. block) like LS1's and 4.6 dohc fords aren't even getting anywhere near that power. Remember also, that rods aren't the only part of an engine -- the block, crank, 90 degree V design, internal or external balance, engine harmonics, cams & valves (heat resistant), headgasket seal (O-rings), torsional stress of a v8 vs. I4, etc all have a play in power levels. Also, the fuel system is very important at those power levels, and anything but methanol/ethanol/C16 or any other high level fuels won't be able to sustain a precise tune with 1000hp (once you get to about the 600hp level in Any engine, alot of variables change).

Basically, until someone comes up with some documented proof (DYNO), anything any of us says has no merit... and I'd rather be conservative than have high expectations and fall short.

Post by **Ezekial** » Thu Jun 08, 2006 6:25 pm

yes i understand all that. to be honest i am shocked you think that the conrods are a weak point. even more shocked since you said you have years of engine building experience. i know i have seen my fair share of conrods and seen what does and doesnt hold up to increased hp ... and i was more than impressed with the VH45 conrods.

my opinion is the same with regards to the block. it is very "meaty", the crank ... well i think i went overkill with nitriding it but it was out so i just got it done ...

i am only trusting the pistons because a) they are flat tops b) i have the functions available to monitor everything about the engine whilst tuning and c) i dont care if it breaks. i will just re-sleeve to a bigger bore and run forged pistons

i agree about 1000 hp being out of reach for anthing but race fuel. C16 or M110 martini at a minimum would need to be used

I think my 800 flywheel hp (600 rwhp goal) is conservative for a 4.5 litre being fed 20psi boost pressure.

Like any performance build, you cant just expect to make huge hp reliably without making sure everything internally is 110%. If you ignore this then its a ticking timebomb.

Like i said ... good information anyway. good work mate

Post by **defrag010** » Thu Jun 08, 2006 6:56 pm

I never said the conrods were a weak point, I said the design of using a cast hypereutectic piston on a steel I-beam rod was a weak point in itself for the kind of power we're tlaking about.It might be shocking to some, but all I'm going to say is that I have built many race motors (small blocks, big blocks, fords, chevys, turbo 4g63's, etc) that have seen high power levels, so I have seen what components work and what components don't based on what fails and what survives at what power levels.. plus I learned from and work with guys who have been doing race motors for 20+ years.I wouldn't give my opinion on this unless I had enough empirical data and experience to form a conclusion from.

Anyways, I will have alot of head measurements tomorrow, so get ready!!

Post by **Ezekial** » Thu Jun 08, 2006 7:34 pm

FWIW the pistons in my little 993 cc (yes sub 1 litre) are cast pistons with I-beam rods.

Factory specs: RPM limiter 7500 rpm. Boost Pressure 10psi 80 hp at wheelsMy specs: RPM limiter 10,000 rpm. Boost Pressure 29psi 200+ hp at wheels

I have built at least 6 other examples as well. All running in excess of 20psi. Approximately 3 years or more on each engine. With the lowest power output of 163 hp. So still over DOUBLE factory power output. Never has one cracked a piston or snapped a conrod. And these conrods are NOT impressive to look at like the VH45DE conrods.

But anyway I hear you none the less.

Bring on the head measurements! I'd offer to measure mine as well to back up your figures but you seem to be more than capable

Post by **elwesso** » Fri Jun 09, 2006 4:14 am

defrag, i got your email!!! Thanks.

Post by **defrag010** » Fri Jun 09, 2006 4:15 pm

I tore down a head, and I was Very impressed with it in stock trim. However, my camera's batteries died when I turned it on this morning to take the first pictures, so no pictures on this trip.

One key thing about the head stuck out to me the most:-Intake ports are EXCELLENT. They are concentric all throughout, low seat/port floor angle, and there is literally no casting flash or ridges at all anywhere inside the intake ports. From the port opening to the bowel is a straight cylinder, meaning if one wanted to port the intake side all he/she would have to do is put the head on a press and bore out each intake port until you hit the bowl, and then blend. They literally do not need any porting at all, unless you want to make the runner volume larger by boring the ports out.

Onto the measurements...

Springs:Spring installed height = 1.455"Zero lift Coil Bind = .930"Seat pressure at installed height = ?? (spring tester was being used while I had free time, maybe later)-Springs are large enough and soft enough to find a stiffer alternative OEM spring off of another type of head that will give enough pressure needed for either superhigh rpm or if you want to run some bigger cams. I messed around and a stock SBC spring fits into the VH45 spring cup and retainer Perfectly, except the installed height and coil bind of the SBC spring were too tall for use on a VH.

Valves:Intake:-stem diameter = .270"-height = 4.05"Exhaust:-stem diameter = .310" / 5/16"-height = 4.45"-sodium filled on exhaust onlyKeys:-7 degrees-diameter = .400"-height = .280"-bead type = round-bead diameter = .075"

I also took measurements of the cam cap bolts so that I can have some made that are low profile 5-point heads vs. the crappy 1/4" torx. I twisted off two different snapon torx bits getting these caps undone, so I think some 5-point head bolts will be nice to have incase you break one off and have to drill the head off of the torx bolt like I did.

-height = 1.56"-shank diameter - .250"-head diameter = .540"-head height = .092"-thread = m6x2.0

Stay tuned for pictures when I get free time Monday!

Post by **TgduMg** » Mon Jun 12, 2006 10:48 am

defrag010 wrote:Stay tuned for pictures when I get free time Monday!

That's why I'm keeping my frequency dial set on NICO!!!

Danisiti 1

Post by **defrag010** » Wed Jun 14, 2006 8:06 pm

as promised: pictures

I tried to focus on the intake port(s) the most. I want to experiment with using a press and a big reamer to bore the intake ports out to 1.25".

straight shot into the back of the intake valve

lookin' back through the port from the chamber

lookin' back through all of the ports

closeup of the above

in through the outside of the exhaust port.. the divider = not the best for flow (which is why I like the siamese intake ports)

shot of all of the exhaust ports. They look like 4.6 ford DOHC exhaust ports only w/ different flanges. Maybe it's possible to use a 4.6 DOHC header mated to a VH45 flange?

1.010" diameter intake ports. I think there is room to bore them out to 1.25"

stock VH45 spring + retainer setting on perch

stock smallblock chevy spring + VH45 retainer setting on perch. The SBC spring is too tall for use in the VH45 head, but it is the right diameter....

underside of VH45 retainer. I would not attempt the use of an inner spring without machining that inner radius down to a 90 degree transition. If you put an inner spring on the radiused part of the retainer, it will present an uneven load and cause alot more stress on the retainer (which could lead to it failing)

Post by **Mettler** » Thu Jun 15, 2006 10:49 am

defrag010 wrote: I would not attempt the use of an inner spring without machining that inner radius down to a 90 degree transition. If you put an inner spring on the radiused part of the retainer, it will present an uneven load and cause alot more stress on the retainer (which could lead to it failing)

Hmmm, wouldn't that potentially weaken the retainer, especially with the load of two springs instead of one ? Would almost be better looking at GTi-R retainers, or custom made ones !

By the way defrag, you might want to modify your posts and put [img] and [/img] before and after each pic link, that way you can display the images directly on the forum here without having to pop up a new window

Post by **defrag010** » Thu Jun 15, 2006 12:39 pm

I tried that in the original post, but they would not show up in the post itself

Post by **Mettler** » Thu Jun 15, 2006 1:14 pm

Hmmm that's most unusual, I just tried it without success too !

I think it's imageshack, cos I can link pics from elsewhere no probs.

Post by **David Steele** » Sat Jun 17, 2006 3:48 pm

How wide are those exhaust ports?

Post by **elwesso** » Sat Jun 17, 2006 6:24 pm

1.010in..

Post by **David Steele** » Sun Jun 18, 2006 5:35 am

elwesso wrote:1.010in..

He said those were the intake ports size, there the same as the exhaust ports?

How about the width and height?

Post by **elwesso** » Sun Jun 18, 2006 5:43 am

IM sorry David, i misread that..

I measured my exhaust MANIFOLD ports which assumably theyre the same as the port on the head with 28mm tall, and 54mm wide..... you can then convert that to inches, but I was using a ruler and its easier to measure in mm.

EDIT: Sorry again, i was not measuring the ports rather the port on the manifold which would be the same as the place on the head.

Post by **Ezekial** » Sun Jun 18, 2006 2:26 pm

defrag010 ... good info on the retainers. from what i have seen gtir retainers cannot be used because of the collets / valve stem size differences.

i will just machine the factory retainers

good photo's once again

Post by **Ezekial** » Tue Jun 27, 2006 3:59 pm

i think this should be a "sticky" topic

Post by **audtatious** » Fri Jun 29, 2007 3:49 am

Bump....

We need to put this info somewhere.....Maybe on vh45de.com if it's not already there......

Post by **marksport** » Mon Jul 09, 2007 9:54 pm

Defrag, can you measure what the dimensions are from the top of the piston to the top and bottom of the skirt, and the piston pin center to the top and the bottom of the skirts?

Post by **Mettler** » Tue Jul 10, 2007 10:04 am

I've modeled a VH45 piston now, I could probably throw the dimensions up tomorrow.

The Master VH45 detailed spec/measurement/part# thread

The Master VH45 detailed spec/measurement/part# thread

Re: (defrag010)

Re: (Mettler)

Re: The Master VH45 detailed spec/measurement/part# thread (defrag010)

Re: The Master VH45 detailed spec/measurement/part# thread (defrag010)

Re: The Master VH45 detailed spec/measurement/part# thread (Ezekial)

Re: The Master VH45 detailed spec/measurement/part# thread (elwesso)

Re: (defrag010)

Re: (defrag010)

Re: (Ezekial)

Re: (defrag010)

Re: (defrag010)

Re: (Mettler)

Re: (David Steele)

Re: (elwesso)

Re: (David Steele)

Re: (Ezekial)

Re: The Master VH45 detailed spec/measurement/part# thread (defrag010)

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