Found compatible custom pistons

[mikev88]

hi, long time lurker, I have been evaluating my options for dropping a high strung V8 in a 240z and the VH45 is on the top of my list. My only problem is the lack of aftermarket, and since I wanna stay N/A that makes it harder to get a bit more power. Lately thanks to a labyrinthitis and beign unable to do anything that involves walking I have done a lot more research. I have found that the 4.6L Northstar V8 has the same 93mm bore as the VH45, 22mm wristpin and a compression distance of 31.5mm... http://kb-silvolite.com/spisto...d=624 or 31.9 http://cgi.ebay.ca/Piston-Set-...wItem

THe problem is that this engine does not enjoy a lot of aftermaket too, however it has more than the VH, this company http://www.chrfab.com/Engines.htm (see bottom of page) has had custom Arias pistons done for their engines. They are available in any compression ratio for 1200$. Expensive but I would trust Arias. Unfortunately the rods are much longer in that engine. So if someone want to rebuild their engine, those pistons can maybe be found for cheaper and are essentially the same , the short compression height one would give a drop in compression of about 0.5:1, could be good for someone that wants to boost a stock engine but needs new pistons, and could take the little drop in compression as a bonus!!!

Just thought I would share,

mike

[mikev88]

Also I am in contact with a company that makes only custom rods, they do not charge anything for customizing the size of the big or small end of the rods, along with the lenght of the rods (billet 4340 CNC rods). Price starts at 800$ a set since our rods are not that far from Chevy 5.8 inch rods which are very common, we might get something out of this at a price close to that. I will keep posted.

ON another note, I wonder up to where the similarity with the Nortstar parts continue, about the same bore and stroke, same pistons, same power, looks like Cadillac might have taken an inspiration somewhere...

[craigztoyz]

On the pistons side, for a lot less, one can get a set from that place in arizona, in .040 over and lower compression that way.from the posts I have read on it, it is around 500 to your door for a product that is being used by guys here with what seems to be no issues. have not seen much on what people are using for gasket kits though The forged pistons would be great, especially to lower rotating mass, but at a cost. I am interested in the similarities of the two motors, and parts. I know that engine has a few adapters made to fit it RWD, and it is a fun motor to get on too.

[T45]

Using the .040 overbore pistons does not lower the compression ratio. It's still 10.2:1. Only increases displacement. For boost apps everyone must still find a different alternative.

[tmorgan4]

If the bore is identical in the Northstar and the overall displacement is only .1L more, how is it going to have a "much longer stroke"? If it's got a very similar displacement and same bore, it seems the stroke should be only SLIGHTLY longer.

[Mettler]

He said the rods are longer, not the stroke. Probably has a higher deck height.

[Olderthanme]

Custom ROSS pistons are around $900 for forged slugs.I don't see why people pay so much for pistons that are for a different application and require modification to the engine...

[tmorgan4]

He said the rods are longer, not the stroke. Probably has a higher deck height.

Ah thanks Mettler. Read that wrong.

[SaintlyCharBoy]

The similarities between the two engines are not surprising, remember, they were both based on IRL engines

detuned and increased displacement, but fairly direct lineage on both counts

[SuperHatch]

Custom ROSS pistons are around $900 for forged slugs.I don't see why people pay so much for pistons that are for a different application and require modification to the engine...

Ditto...

Of all the custom parts you can have made for an engine, Pistons are some of the cheapest when compared to "off the shelf" solutions. From most companies, it's barely a 5% price difference.

[mikev88]

Superhatch I am just trying to find some alternate (Cheaper) solutions. I also found it interesting that the pistons are basically identical. I am happy however that the price for custom pistons are good since I dream of having a set of something like this http://cgi.ebay.com/ebaymotors...ZWDVW with a set of this http://cgi.ebay.com/ebaymotors...36042 400 grams!!!!! that is the same weight as the VH piston!

As for the rods manufacturer, turns out that they are 900$ but for aluminium, 4340 rods are 1300$.

It is interesting to note, that the company that does reginds for for the northstar says that their middle cam ( 288 degrees of duration) is good for a 75 HP increase over stock. They have to more cams that are wilder, that should motivate people!

[Olderthanme]

Using the .040 overbore pistons does not lower the compression ratio. It's still 10.2:1. Only increases displacement. For boost apps everyone must still find a different alternative.

Increasing the bore, while all other measurements stay the same will RAISE the static compression ratio. Think about it. More air getting squeezed into the same cylinder head chamber area...

On another note... People way under-estimate the stock rods. Sure they look weak, but they are FORGED steel with much higher metallic properties and quality than many aftermarket units. With a simple race prep(balance, polish, shot peening, and magnafluxing) the stock rods would be good for LOTS of RPMs and LOTS of power. Well more than 99% of the VH people on this board are ever going to be making.800hp should be fine on stock rods.

In the 70's to 80's Nissan rods were holding 4 times the original power with a simple race prep.
Modified by Olderthanme at 4:45 PM 2/20/2008

[T45]

I always considered CR to remain constant with bore changes since the stroke remains the same. Guess I'm wrong. Learn something new every day...

[245sx]

when i was reading, i read some of the sae papers and it mentions the vh rods being made out of a 1065 or 1080 alloy steel, which from further reading isnt even as good as 5140 alloy steel which is what the cheapiest aftermarket rods are made out of. they are the same alloy as stock small block chevy rods