It woudl be useful if those in the list posted there requested specs. ie. CR and bore. I am pretty sure I want .02 for bore but I am still a little on the fence about CR. But I am swayed towards the 8.5 as of late. gg as people respond maybe you could add a column to your list?

On a side lne , what CAMs and grind are people considering for the Forged bottom end and FI ? :OEM , Nismo, Tomei, Crane.
I was inclined to stick with OEM but if someone makes a convincing argument otherwise.... don't want to F- up the sniffer test in Ca.

Do I smell another GB? I heard Crane was in the works?

 

Hang tight. I am writing up the formal group buy right now. You will have the option of 8.5:1 or any other compression ratio of your choice. You can also choose stock bore or .02 overbore. Don't recommend more than .02 on our stock sleeves.

: I am getting excited....are you? Yippie!!!

 

I've never participated in a group buy or anything like this. What kind of time frame are we talking here? Any chance I can have them on my doorstop tomorrow morning???????

Thanks,
Kevin

 

Sharif,

I may be in with you... you know what I have going on, but I have yet to get anything definitive. I'm told I will have figures tomorrow.

Not holding my breath until I see them, tho. Failing that, I'm going to be in for some standard bore 9:1 pistons and a set of rods.

 

I may be interested in this also.

 

Originally posted by gq_626
Pauter Rods/Arias Pistons Group Buy Interest List:

1) Gq_626
2) zimbo
3) KPierson
4) adxcpa
5) Enron Exec
6) igor@af
7)whosdady
8) G3po
9) Bini2
10) ZCool
11) Houston G35
12) 350G
13) jak (rods only)
14) Rspec
15) McDuck
16) slay2K



ahh.....no.... 4-5 weeks. Most of this stuff is always custom made to order.

 

OK, the group buy is official posted! It will run for just 7 days.

You wont believe the prices....woohoo!

https://my350z.com/forum/showthread....threadid=85958

 

Sharif, I'm definitely in on this and will send you my money in the next day or two.

In the meantime, pardon the dumb question but why would I choose (or not choose) stock bore versus 0.020 overbore?

Also, for those who have done this before, what is involved to replace pistons? Is the overbore so that custom machining can be done during the rebuild to ensure the best fit? (sorry for the dumb questions)

--Steve

 

It was explained to me that you have to 'rough' up the cylinder walls in order for the new seals to seat properly. Basically the machine shop will put very small scratches in the cylinder wall (up to 0.020" deep) and when the pistons start moving the piston rings will rub the scratches out and everything will end up all smooth and sealed in the end. I am in no way an expert on this though, and this is the first engine that I will ever build, so maybe someone with some more experiance can explain better.

Kevin

 

Good question...I will call up Arias and find out.

 

Just spoke to Arias. To do a .020 you actually have to fully hone the cylinder wall a pretty good amount. It's not just done to "scuff up" the cylinder walls. If your cylinder walls are strong enough, you can go .020, but again, it requires significant machining, and also results in an increase of displacement from 3.5L to 3.54L . Becuase I am unsure of the strength of the stock cylinder walls, I am going with stock bore.

Also, if your cylinder walls are damaged, or if the motor is in poor condition, you probably wanna go .020 so you end up with a nice clean seal between the rings and walls.

I am also not an expert engine builder...hehe...so if anyone has more info, I am ready to listen.



Hth,

Sharif
_______________________________________


OK, the group buy is official posted! It will run for just 7 days.

You wont believe the prices....woohoo!

https://my350z.com/forum/showthr...&threadid=85958
I am going stock bore, becuase I dont wanna weaken the stock sleeves.

 

Because the diameter of the pistons and sleeves have changed, any new pistons you are using in this motor will require the new pistons to be slightly larger. The cylinder sleeves must be machined to the new diamter of the pistons. Each piston is numbered and specificly fitted for one specific cylinder.

 

Well here is my stab, I have personally re-built many V8s in the long past , but the prinples are same for the VQ.

Note that SGP uses a .02 overbore , I beleive in all of there past 8 VQ35 builds. So they at least thinlk the sleeves are meaty enough for the power levels up to 6oo rwhp.

There are two basic processes performed on a cylinder bore, druing a re-build.

a) boring - used to increase size of bore, provide a clean round bore and remove imperfections due to prior cylinder wear.
This process "must" be done by a qualified machine shop.

b) honeing- used (even after boring) to create a mild cross-hatch pattern in the bore surface. Very little material is removed in this stage. It is done to promote proper break-in of the Piston rings.
You at least need to hone the bores or you risk inadeqaute ring setaing during the breakin interval. You could hone your cylinders in your own garage if you wanted to, the tool is cheap. Note , even with a brand new block ,the OEM hone itself may not be adeqaute to accomadate the harder material used on the compression rings supplied by ARIAS. And after a the first few K miles on an OEM block the hone pattern is no longer present

Since I am not exactly sure as to the condition of the cylinder walls of the second block I am attempting to buy , I will defualt to .02 bore + hone to be safe.

 

I lifted this from hotrod magazine. Overborig is commonly done in high mileage or badly worn cyclinder walls. It's debatable whether we need this or not, since most of our motors have less than 20K miles on them. That's the beauty of this group-buy...its like McDonalds...you CAN have it your way...any way!
__________________________________________________
Cylinder Bores

Because they must contain the forces of combustion, and accurately locate the pistons, the cylinder bores must be in tip-top shape. The bore diameter is of primary concern: The closer to the original it is, the better; wall thickness and strength are maximized. But in most cases, used blocks come from high-mileage vehicles. The cylinder bores usually have considerable wear that is correctable by overboring. Overboring removes metal, and should be limited to a bare minimum to preserve strength. Before requesting this modification by the machine shop, make certain that replacement pistons and rings are available.


Although an easy way to gain displacement (a .060-inch overbore typically adds about 12 ci to the total), resist the temptation to bore your way to extra cubes. Once the bore is expanded .060 inch (less in certain cases), it is essentially unrebuildable. A better plan is to make a .030-inch cut (or whatever it takes) to clean up the bore. From the ’70s to the present day, many manufacturers have reduced the metal content of their blocks in the interest of shaving pounds and cutting costs. Most notably, the Chevy 305 and Mopar 440 (those cast after 1974) should be sonic-tested if the anticipated overbore will exceed .020 inch.

 

One more thing guys, if you dont plan on adding new sleeves, are there any other methods of reinforcing the open deck?

 

Well from the blurb, even if you bored a cast block ot the max limt, it can stilll be "sleeve". THe VQ design is an aluminum block with iron sleeves. So , unless the blcok is damged (ie by throwing a rod etc.) you can usually re-sleeve it even if you a have no more over-bore options.

Also note even with the "standard" bore piston, the bore may need to be opened "slighty" to make clearance for the forged pistons. The OEM Cast piston can fit more snuggly into the bores, by design (rate of expasion more closely matches the sleeve.

The Forged counterpart on the other hand has a larger differential thermal expansion rate than OEM and hence probably require a little more room. THis useually result in a little more piston noise during warm-up.

 

Sharif,

Payment sent to your PayPal account. Thanks for all the work you did to pull this group buy together. Now I need to find an experienced and not too expensive shop for installation.

 

Thanks Zcool...two payments have already come in in just an hour! And two more and confirmed to pay today...we're off to a great start.

I completely forgot that the forged pistons will fit slighly looser than stock to account for greater heat expansion, so maybe overboring is not needed? I agree that honing is always needed, to ensure a good seal and surface for break in.

Does honing also correct to get a perfectly round bore?

Damn...will an engine builder please chime in with the authoritative answer...LOL

For those that have paid, if you decide to change your bore size, no problem...just lemme know sometime before the group-buy ends.

 

All I can say for sure is that honeing does not round up the bore.
I've actually driven a numeric line-boring machine before, it is a very precise piece of gear . A hone is a simple device with little correlation to bore center. When SGP responds we'll see what the real experts recommend..

 

Not really. You could take your stock sleeves, and then just "pin" the deck "or semi-close it. But if you do that, might as well just sleeve and close the deck at the same time.

The only other thing I plan on doing is installing high strength ARP head and main studs. SGP racing sells them for $399 Maybe we could do another group buy on them??