I would ask Venolia what all specs they need. They might have 4g63 specs on hand and just want to know what you want changed. 69.25/piston (90/piston fully machined) is a DEAL, I think I'll give em a call here in a month or 2 to get a set made for me. For my set these would be my specs:

8.5 Compression Ratio
Lowered Compression Ring Lands
Heat conductive coating on sides
Heat Resistant coating on top
Full Floating Pins
Chrome Molley Rings

I will be running Nitrous so the lowered compression rings are a must to keep from melting them. Also see if they will beadblast the tops of the pistons before coating...you don't want any hotspots on the pistons due to sharp edges left from machining.

Hope this helps.

 

Why would you bead blast the tops of the pistons, the pistons are made from a cylinder shape type stock, all sides of the stock get machined and then machined again for its finished look, if you have ever ordered pistons with rough edges I recommend staying away from that company. With companys like JE, ROSS, Wiesco that isnt something you should worry about, Ive never dealt with Venoila but I hear that there pistons are top quality.

Storm

 

How much would you lower the ring lands by? I've read about it but they never give any examples as to how much...

 

Are they stock '95 pistons?

 

If you're talking about the Venolias then no, they're forged pistons that I'll be ordering to my specs.

 

I know a guy who has Venolia pistons in his Stealth. I don't know if this is any help, but here is the content of the pistons.

Content (nominal):
Alloy Number: 2618-T61
Cu 2.21%; Mg 1.2%; Fe 0.98%; Ni 1.08%
Coatings: none; Silicon: 0%


Chris

 

Beautiful car btw KD4PWH. What's his overall impression of them? What kind of clearances, and how much piston slap has he experienced?

 

Why would you bead blast the tops of the pistons, the pistons are made from a cylinder shape type stock, all sides of the stock get machined and then machined again for its finished look, if you have ever ordered pistons with rough edges I recommend staying away from that company. With companys like JE, ROSS, Wiesco that isnt something you should worry about, Ive never dealt with Venoila but I hear that there pistons are top quality.

Storm

The edges aren't rough...but sharp. Machining leaves "crisp" edges on the machining surfaces, and those sharp edges are potential hotspots. Bead blasting makes those edges round and decreases the chanses of hotspots in the cylinder and thus reduces detonation. It's usually really cheap (like $40) and is well worth it.

 

I havnt seen a piston with such, as a machinist, ive machined tons of aluminum and have had tons of rough edges that needed to be deburred and just about all of the orders that we had machined always recieved a deburring process afterwards with the acception of a few, however our mother company would not accept anything that was not smooth, reason is that someone could get hurt during shipping, packing, etc...

When I had ordered my ROSS pistons, this was not a problem, they had taken steps to include the finishing process in their CNC code. But I guess with the cheaper companys, it could happen.

Storm

 

Which edge are we talking about here? The edge of the crown, skirt, ring lands, pin? Could these rough edges screw up you cylinder wall if not done correctly?

EDIT Nevermind, I just saw "top of the piston"... So if you have rough edges there could you sratch or damage the wall? Probably nothing big enough to worry about, right?

[Edited by davejcb on 12-15-2001 at 11:50 AM]

 

Beautiful car btw KD4PWH. What's his overall impression of them? What kind of clearances, and how much piston slap has he experienced?

Thanks Dave! I'm pretty sure that is is very satisfied with the Venolia pistons. This guy is very knowledgeable and very big on 3si.org. Here are his clearances taken from his website. Keep in mind this is for his 6G72TT engine.
RECOMMENDED CLEARANCES
Piston Clearance Top of Skirt: 0.008-0.010 in. (0.2030-0.2540 mm)
Bottom of Skirt: 0.005-0.007 in. (0.1270-0.1778 mm)
Ring Clearance Side Clearance: 0.003-0.004 in. (0.0762-0.1016 mm)
Ring Gap: 0.004-0.005 in. per inch of bore
Pin Fit 0.0006-0.001 in. (0.01524-0.0254 mm)

Check out his website for tons of info, not just on 3/S, but on cars in general. Lots and lots of good information on there. http://www.stealth316.com


Chris

 

Great stuff Chris. I found that site somehow before, has TONS of good info. Also thanks for the clearances.

Has he mentionned anything about how much piston slap he is getting with that setup?

 

Not that I have heard....you may try emailing him and see what he says. I doubt that it is much.



Chris

 

Venolia Pistons

I just spoke to Venolia in California, I can get the pistons for 69.25$, 15.15$ for the pins and 3.25$ to fit them, and all to my specs!!!



This sounds really cheap for forged pistons do you have there number handy im going to give them a call.

 

Why the rolling eyes???

 

Venolia

Cause im wondering what the number is to Venolia Can you PLEASE give it to me.

 

OK I though you were being sarcastic... Go to http://www.venolia.com/ the number and address is on the front page.

 

Venolia Pistons

So have you figured out the specs on the pistons your going to be ordering from Venolia? What kind of rods were you going to use with them? Are you going to the floating pin mod? Let me know im intrested since we both have 6-bolts. Later

 

No, I never did. Basically the project is on hold, I just had to pay for school (back in college now)... Plus I decided that drag racing would be boring for me, so I'm not gonna build up my bottom end for it anymore. I was gonna go with Venolias with Eagle rods, normal pressed pins (floating pins and knock don't mix). Instead I'm building the car for autocross and maybe rally racing if I can't get into it, so I'm gonna go with 2G pistons, shotpeen and polish my stock 1G rods, and blueprint the bottom end.

 

I was gonna go with Venolias with Eagle rods, normal pressed pins (floating pins and knock don't mix). Instead I'm building the car for autocross and maybe rally racing if I can't get into it, so I'm gonna go with 2G pistons, shotpeen and polish my stock 1G rods, and blueprint the bottom end. [/B][/QUOTE]

I was either going to go with Venolias with Eagle rods or my big 1g rods or the EVO 8.7:1 pistons bored .020 over and use my big 1g rods. my engine was already rebuilt about 30k ago with 2g pistons so my rods have already been machined to fit. So the Evos will fit right up to my rods. What does Shotpeening the rods do? Do you know about how much it would cost? Is blueprinting expensive? I know that envolves staying between certain specs when rebuilding the engine but is it worth the extra money.

What setup do you think I should go with, I want to push out a little over 450hp to the wheels.

 

Shotpeening if basically taking a part and shooting it with lead shot, which reinforces it.

Blueprinting is a very expensive process if you get it done, it basically means every tolerance should be right on, the point of it is to eliminate the margin of error they have at the plant when they build the engine. It's the way it was meant to be, but if they did this at the plant it would cost way too much.

For 450HP I don't see why you wouldn't be OK with 2G pistons and stock rods, people have done it without problems before.

 

what pistons will work with my

stock 1G pins? From dsm.org it appears that you need new pins when fitting 2g pistons to 1g rods. At Buschar the 2g pistons/rings are $225, when you add pins the price goes to $700!!!!!

Since cost is a major priority I would like to keep my rods and pins, what pistons work with this setup?

What's my best bang for the buck approach? looking at 400 HP max

Thanx

 

Re: what pistons will work with my

stock 1G pins? From dsm.org it appears that you need new pins when fitting 2g pistons to 1g rods. At Buschar the 2g pistons/rings are $225, when you add pins the price goes to $700!!!!!

Since cost is a major priority I would like to keep my rods and pins, what pistons work with this setup?

What's my best bang for the buck approach? looking at 400 HP max

Thanx

That $700 dollar price is for the pistons and labor on machining your 1g rods to fit the 2g pistons.

What state you live in. You should be able to find a Machine shop that will machine your 1g rods to fit up to 2g pistons for about a $150 dollars then you have to buy the 2g pistons which would be close to $300 from a Mitsu dealership with a 25% discount.

If your a DSM member you should be able to get a 25% discount from one of your local Mitsu dealerships. That would be the best place to buy parts for your car then bring the whole engine in to a Machine shop and have them assemble and balance it along with machining your rods. And well your at it have the balance shafts removed if you havent done that already and make sure you use a Metal Head Gasket. If you do it this way it shouldent cost more then 15 to 1600 dollars for the whole rebuild. Then you have to drop the engine back in yourself. This setup should be able to push out 400hp with the right turbo.

Now if you have a 92 or newer with a 7-bolt in it forget everything I said and buy a JDM 6-bolt motor from Japan for like 1500 there are numbers listed on http://www.roadraceengineering.com If you want some more info.

 

thanks but more questions!!!!

So then do i need 2g pins as well or not? does that $300 include the new pins if needed?

Should I get OEM rings or aftermarket (total seal/etc..)

Should I do anything to my stock rods? shotpeen/cryo/polish?

Which metal HG? or should I o-ring?

Thanx

 

Re: thanks but more questions!!!!

So then do i need 2g pins as well or not? does that $300 include the new pins if needed?

Should I get OEM rings or aftermarket (total seal/etc..)

Should I do anything to my stock rods? shotpeen/cryo/polish?

Which metal HG? or should I o-ring?

Thanx

Sorry, yeah it should be about $300 dollars with the rings, I would get the OEM rings you can get them for a discount and there just as good if not better then total seal rings. The pistons should actually be like $40 dollars a piece and the Rings will be about a $100.

Im rebuilding my engine right now (1g 6bolt) and im going to have my machine shop shotpeen the rods for me. It makes them stronger and reasures that they dont crack(it might be a good idea to have them polished as well) im going to look into this. There going to charge me $60 dollars for it I dont know how much it would cost you. Im going to use a Mitsubishi 4-piece Metal headgasket to keep the compression up. I bought mine from RRE you can O-ring the engine if you want, it will give you even better compression so you can push out even more boost but it costs a LOT of money, not real sure how much. And im using EVO 8.7:1 pistons with my 1g rods instead of the 2g pistons which I had already. My pistons are on backorder for 4 weeks and I only found one place in the whole country that can get them. But there a few grams lighter then the 2g 8.5:1s and have a higher compression.

If you have any other questions let me know. Later