Big 1g Rods with Forged Pistons?

[Travi2506]

Alright I did some searching, but couldn't really find anything. Anyways, I was planning on going with the stock 6-bolt rods, and '95 pistons, but I figured that I don't want to have to do this again anytime soon, So I'm wondering about forged pistons. I have a 2g, so I believe I'll have to have the rods machined to fit the crank, but if I were to get Forged pistons for a 6 bolt, then I could get the compression that I want without having to machine the rods to fit. Is this possible? Or do I have to get the 2g pistons?

 

[talon1987]

You shouldnt have to machine the rods to fit the crank .... To put 2g pistons on 1g big rods you have to machine the small end of the rod so the 2g wrist pin can fit. http://vfaq.com/index-main.html -- but in my opinion i would just get forged pistions becasue by the time you buy a set of 2g pistons then have the the rods machined, you could have just payed a little bit more and got your self a nice forged piston. just my .02

-Fitz

 

[Cs4g63]

If you have some extra money get the H beam rods and some forged pistons. No more worries after that.

 

[JayRolla]

There is no reason to upgrade the pistons if you are not upgrading the rods. Just in my opinion. You dont want to keep through power at your motor thinking its safe just because the pistons can handle it. The rods will eventually break. You dont want a weak spot like that. Either just go with 2g pistons or buy upgraded rods and pistons.

 

[Travi2506]

You shouldnt have to machine the rods to fit the crank .... To put 2g pistons on 1g big rods you have to machine the small end of the rod so the 2g wrist pin can fit. http://vfaq.com/index-main.html -- but in my opinion i would just get forged pistions becasue by the time you buy a set of 2g pistons then have the the rods machined, you could have just payed a little bit more and got your self a nice forged piston. just my .02

-Fitz

Yeah, that's my thinking... I know the stock 6-bolt Rods are capable of well over my goals, and I'm limited to funds, so why waste the money on rods I don't need?

 

[Travi2506]

So when I order pistons, can i just get 8.5 compression on a forged piston for a 6-bolt?

 

[TurboDSMer]

After reading your post are you planning on putting 6 bolt rods on a 7-bolt crank? Because if you aren't it certainly sounds like you are.

 

[Travi2506]

Yes. Is that possible?

 

[arash15]

6 bolt rods = 6 bolt crank. 7 bolt rods = 7 bolt crank

 

[Travi2506]

They can't be machined?

 

[Travi2506]

6 bolt rods = 6 bolt crank. 7 bolt rods = 7 bolt crank

Can you explain this? What's the difference in the cranks? And If the rods can be machined to fit 7 bolt pistons, why can't they be machined to fit a 7 bolt crank? Can anybody else verify this?

 

[DJYoshaBYD]

the 7 bot crank is bigger than the 6 bolt... I would assume too much material would have to come off the rods to fit it on there.... like homeboy said, you dont want a weakspot like that in your bottom end... it just asking for trouble.... keep searching, and I am sure you will find a rod/pison combo for a decent price....

 

[JayRolla]

Yeah, that's my thinking... I know the stock 6-bolt Rods are capable of well over my goals, and I'm limited to funds, so why waste the money on rods I don't need?

If the OEM rods can handle what ever your going to through at them, then so can the piston. The record is over 550whp on stock internals and I think he actually retired the block. Never blew up on him.

 

[DJYoshaBYD]

because of a couple of reasons...

the amount of material that has to be machined off to fit the pistons isnt that much... its a very small bore job...

The rods can be machined to fit a bigger crank, but then you run into a problem:

Too much material has to be taken off the rods to fit the crank, so it would most likely make the rod weak in the machined area

 

[Travi2506]

If the OEM rods can handle what ever your going to through at them, then so can the piston. The record is over 550whp on stock internals and I think he actually retired the block. Never blew up on him.

Ha... I'm not planning on anywhere near 550whp, so I think I'm just going to go all back to stock... Anybody know what the limits of the 2g internals are?

 

[DJYoshaBYD]

a little less than a 1g 6bolt just because of the fact that the 2g 7bolt has smaller rods and high comp ratio pistons.... if you tune it right, you should be able to push alot of power for a street car and it will last.... All you taking all the preventative measures to avoid crank walk with that 7bolt??

 

[burnnxs]

i run wiseco 8.5.1 w/ 1g rods, my goal is close to 400hp i dont see no problem w/ them being weak and breaking at that point so...

 

[1gcrazy]

i run wiseco 8.5.1 w/ 1g rods, my goal is close to 400hp i dont see no problem w/ them being weak and breaking at that point so...

and thats why you're new....

Dude, i just posted this in another guys thread that was building a 2.3 stroker. You can make a lawnmower do 11's as long as its tuned right.....
Its allllll in the tune its alllllll in the tune its allllll in the tune

 

[Travi2506]

a little less than a 1g 6bolt just because of the fact that the 2g 7bolt has smaller rods and high comp ratio pistons.... if you tune it right, you should be able to push alot of power for a street car and it will last.... All you taking all the preventative measures to avoid crank walk with that 7bolt??

Enlighten me, PLEASE.

 

[DJYoshaBYD]

enlighten you on what? Checking the endplay on you crank before you put it all back together is all I meant... Im confused... Vat do joo vant to know?

 

[Travi2506]

Already done... It's fine, thank God. I've heard of ways of preventing it with some machine work during a rebuild... Not sure if it's true or not, I've just heard things. I'd really like to do a 6 bolt swap, but I'm still in school and money is very tight, so I think I'm stuck with the 7 bolt for now

 

[Xeiros]

If I may ask, what are you goals? Are you doing this so that you can push more boost in an attempt to hit a higher HP mark, or is it just simply a rebuild so to speak?

 

[Travi2506]

Well, Mods are in my profile. The whole thing started when I spun a rod bearing. Luckily my mechanic had a spare bottom end in the garage, so now that's in. One problem, the compression is really bad in one cylinder, and I'm not helping it with 19psi... It's tuned quite rich, but it's still 100k+ miles old. Basically I'm not looking for anything too crazy... 300-350whp on a mustang dyno with or without methanol. I'm not saying I need to do it on the 16g, but that's pretty much the goal. Any comments/recommendations would be greatly appreciated.

 

[Xeiros]

I'm not sure about the differences on dyno's and what not, but I'd imagine some replacement OEM 2G pistons and some eagle rods would do you fine. That would be one of the more cost effective ways to go anyway. I seen you could get 2G Mitsu Pistons for $200 at SBR and the Eagle rods were about $350. That should be plenty for what you want. Now...if you ever wanted more, yeah it would be a good idea to get a different set of pistons to go with the rods.

--edit--

BTW, from what I've seen, most people seem to agree that the limits for 2G's stock internals are somewhere around 400-450WHP, so that would exceed your goals by a little bit.

 

[Travi2506]

I think I'm just gonna go back to stock then. I'd love to go forged but I really don't have the money right now, and from what I've been told, for my goals, its more of a piece of mind issue, than strength. Sure the forged internals are going to be stronger, but this is a daily driver, and I'm nowhere near the limits of the stock internals, so I think I should be fine. Thanks for everybody's help. If anybody thinks of anything else helpful please let me know.