turbophein
(Member ++)
12/26/14 02:50 PM
What pistons and what rods?

i wanted to build my own bottom over the winter for minimal investment while focusing on the details that really matter.

i have never bought upgraded pistons or rods but have done stock rebuilds. after just looking on parts are fairly cheap.

i have spare 6 bolt virgin blocks, i can drop one off at a machine shop for inspection, etc.

eagle rods $289 i thought was pretty cheap. 6 bolt rods for 2 pistons. which is the setup i would like to do.

now for pistons i have no idea what i want. i found a few sets of forged pistons for under $400 and some Nippon racing Pistons for $175

add some bearings and machine shop time and i think $1000 total cost would be achievable.

curious to hear from you guys.

my goals are to have a strong built bottom end able to handle 500-600hp if i ever get there one day. 400hp reliably for 20k miles would be a dream come true i think.


coyotes
(Hipster VR4)
12/26/14 03:00 PM
Re: What pistons and what rods?

Why can't you do 400 reliably on a stock engine with headstuds and gasket?

slugsgomoo
(god hates stupid people)
12/26/14 03:12 PM
Re: What pistons and what rods?

I'm kind of with Coyotes on this, unless you're trying to bump compression and get a bit more low end...?

For "cheap" pistons, wiseco 1400HD? Not *that* cheap but regular wiseco seem to have skirt cracking issues and the 1400HD are bulletproof. I will caveat that with the fact that I ran a 2.0 with regular wisecos and it held up fine with an evo3 @ ~22psi (9:1 compression) for quite a long time before I sold it.


jeverts
(Member +)
12/26/14 03:59 PM
Re: What pistons and what rods?

Eagle-Wisecos are pretty much the cornerstone to 4g63 lower end building. Probably the best price for the power you can make on it. A lot of people can get into the 700hp range safely with that. After that you are looking at a new crank and turbo tuffs or some sort of I beam rod. ACL race bearings, mains and a 20g or 5858 you can drive 400hp all day long.

jeverts
(Member +)
12/26/14 04:02 PM
Re: What pistons and what rods?

I would agree with Coyote. On the other hand...you are already at the stage of putting in rods and pistons..spend the money and be done with it.

slugsgomoo
(god hates stupid people)
12/26/14 04:29 PM
Re: What pistons and what rods?

also unless you're going for insane power levels, building a forged internal engine with <9:1 compression is stupid IMO.

All the money, virtually none of the benefits. Stock pistons will hold ~500hp and be good for 130mph traps. Built motors in a street car are all about low/mid range, hilarious power. One of my friends is building a 10:1 2.4L... that's where the hilarity factor goes straight to 11.


tektic
(Senior Member)
12/26/14 06:33 PM
Re: What pistons and what rods?

I vote Eagle rods with 22mm wrist pin And the nipon 2g pistons with floating pin.
I think I'm going to be putting one of these together with my spare block.


coyotes
(Hipster VR4)
12/26/14 06:36 PM
Re: What pistons and what rods?

Quoting slugsgomoo:

One of my friends is building a 10:1 2.4L... that's where the hilarity factor goes straight to 11.




one of these years it'll run


slugsgomoo
(god hates stupid people)
12/26/14 06:54 PM
Re: What pistons and what rods?

machininst took a long time. The short block is actually assembled, but progress has been slow due to a couple other things. The car is fine on the stock bottom end though.

biglady112
(or what)
12/26/14 11:03 PM
Re: What pistons and what rods?

Going to a larger 22mm wrist pin gains you no advantage if you still have a flacid wrist pin. When will people understand that? If you are going to make a big deal about it go with a quality material in a thickness that will actually benefit you. I would invest correctly if you are going that far. If you get a low end for like that or any rod for that matter have the machinists check for weight equality, bore sizing, pin fitment and if you go through with it please invest in a more modern design than a cheap ass $350 piston. In my eyes the heavier the better across the board. As with everything we start to get greedy and push things. Might as well over build it if you are in there.

With that said I have had tremendous luck with Arias pistons and either GRP aluminum or Pauter chromoly rods. I am going to say those are likely not economical or focused towards where this car will be used. Just remember, you get what you pay for.


GSTwithPSI
(A hole)
12/27/14 12:15 AM
Re: What pistons and what rods?

Tektic mentioned using a 22mm wrist pin because that's what standard 2G pistons come with, not because they are stronger. I'm assuming he said that due to the OP wanting to run 2G pistons hung on 6 bolt rod...A normal 6 bolt rod having a 21mm little end of course.

WTF is a flacid wrist pin anyways?


biglady112
(or what)
12/27/14 06:19 AM
Re: What pistons and what rods?

Any off the shelf piece of shit .200" and thinner. The kind you get with cheap ass pistons.

tektic
(Senior Member)
12/27/14 09:12 AM
Re: What pistons and what rods?

The op asked for an economy build, and you suggest aluminum rods. Ok 3/4 of the budget down.

Then after suggesting aluminum rods you say get the heaviest pistons you can find? Is that to make up for the weight lost using aluminum rods? Off the shelf Pistons are infered to all be shit. So custom heavy pistons with a wrist pin bigger than .200", so they are not flacid right?


prove_it
(my racist jokes aren't actually funny)
12/27/14 09:25 AM
Re: What pistons and what rods?

I've had great luck with my eagle wisecos. I wish I had gone higher compression, but it was my first build. I do hate on my wisecos though. They make a crappy noise at idle once hot. No performance issues and I've gone 27k miles with no loss in compression. Just an annoying knocking type sound. When I do rebuild it again, I plan on going to 9.5:1 on JE or Mahle pistons. I've heard both brands hold up good in under 600whp builds. Got a buddy making 900whp on Mahle with no issues so far.

I do vote that if your building it, go for it. Do it now otherwise you'll regret not forging the bottom end. I did it to lose rotating weight, which is noticeable. I had a frozen pin on #4, so I needed parts anyway. It wasn't much more to run the eagle/wiseco combo anyway. I think it was about 400 bucks more than fixing the stuck pin.

Sure you don't NEED to, but seriously, do it once and be happy. Otherwise you'll want to rebuild it and then your on jackstands again and you grow to hate the car cause you can't drive it.


biglady112
(or what)
12/27/14 12:41 PM
Re: What pistons and what rods?

Get the heaviest piston and rod you can. Plain and simple. The lighter is better thought does not apply when pushing a forced induction engine. And you will see that I did not recommend the rods first. Anyone considering investing needs to look past the basic 15 year old designs that are the cheapest options out there. For another $150-200 you can get a quality piston. And for those that do not know, make sure you invest in a quality wrist pin. The thin pins are crappy material and do not hold up to long term abuse. A motor I just tore down proves this. And get a thick pin as that is a key element people look past. The off the shelf ones are garbage and flex quite easily. I was pretty clear in what i thought would work, even though it is not in most folks budget. Regardless of what you spend, you better make sure the parts are right and not just assume.

Jesus_Negros
(Unempowered ADMIN)
12/27/14 01:35 PM
Re: What pistons and what rods?

Possibly newb question here:

What is the benefit of a heavy piston/rod combination vs a lighter piston/rod combination on a forced induction engine?


biglady112
(or what)
12/27/14 02:23 PM
Re: What pistons and what rods?

More material to take the abuse and girth for the durabilty/longevity. Something I learned racing at Bonneville. Just look at the diesel stuff and follow their lead. Each motor we have put together with heavier parts has just lasted and taken an ass whooping. 600-1000hp four cylinders wide open for five miles at a time. Multiple times in a day, for an entire week of racing. Of course issues arise and other things like head gaskets and such may not last

362Ryan
(Not Newbie)
12/27/14 07:02 PM
Re: What pistons and what rods?

I'm with Biglady on this one.

I went with Wiseco HD's, tool steel wrist pins and K1 rods.

The machinist said the rods were some of the toughest he has worked with.


tektic
(Senior Member)
12/27/14 10:51 PM
Re: What pistons and what rods?

Quoting turbophein:

i wanted to build my own bottom over the winter for minimal investment while focusing on the details that really matter.

my goals are to have a strong built bottom end able to handle 500-600hp if i ever get there one day. 400hp reliably for 20k miles would be a dream come true i think.




When I see things like "if i ever get there one day" it makes me think this engine will never see more than a 16g turbo. A reliable 400hp makes me think he shouldn't even bother with a forged piston.

It Sounds to me like he wants an engine that starts in the cold and doesn't make noise, not one that can handle 1000hp.

Biglady; you may have the right answer, just not to this mans question.


EMX5636
(Carbon Fiber Cage)
12/28/14 09:37 AM
Re: What pistons and what rods?

Quoting 362Ryan:

I'm with Biglady on this one.

I went with Wiseco HD's, tool steel wrist pins and K1 rods.

The machinist said the rods were some of the toughest he has worked with.




Not trying to divert too much off topic, but everything I've seen about K1 is they are the same as Eagle/Scat. I've been lucky with 9.0 Wiseco's, and R&R rods in mine, costly, but has been 100% reliable for close to 30k miles now at over 500whp.


And to answer the OP's question a bit more, your Eagle 2G setup is a decent cost effective one, but for not much more money, you can an off the shelf from various companies and have a higher window if you want that 5-600hp later on.

Are people still looking for the factory forged Evo9 pistons and installing them? It's been a few years since I've looked for factory parts builds.


turbophein
(Member ++)
12/28/14 12:54 PM
Re: What pistons and what rods?

Quoting tektic:

Quoting turbophein:

i wanted to build my own bottom over the winter for minimal investment while focusing on the details that really matter.

my goals are to have a strong built bottom end able to handle 500-600hp if i ever get there one day. 400hp reliably for 20k miles would be a dream come true i think.




When I see things like "if i ever get there one day" it makes me think this engine will never see more than a 16g turbo. A reliable 400hp makes me think he shouldn't even bother with a forged piston.

It Sounds to me like he wants an engine that starts in the cold and doesn't make noise, not one that can handle 1000hp.

Biglady; you may have the right answer, just not to this mans question.




i want to build a reliable engine with the correct tolerances needed, thats what i meant about focusing on details. i can afford to build whatever i want, i choose not to, its my nature. but if i can get a good deal on parts and do the build myself which i really enjoy doing, thats what i want. maybe one day i will get a turbo setup capable of 500hp plus.

also my signature is not updated. i just bought back my old car with heaps of problems i am sorting through and it has none of the original parts. i just finished putting in a engine i assembled this week. spare stock 6 bolt bottom end i had and rebuilt 2g head. its raining or i would finish the tranny install and attempt the first start up.


Thanks for all the posts, lots of food for thought.


presterone
('92 Protege VR-4)
12/28/14 04:06 PM
Re: What pistons and what rods?

So I take it your not gonna sell it? Lol good to see another gvr4 is going to be kicking around new england

mitsuturbo
(Banthony )
12/28/14 05:48 PM
Re: What pistons and what rods?

Mahle 4032 forgings are super low expansion. Cold weather starts aren't really an issue like with 2618 slugs.
Also, eagle does now sell 6 bolt rods that fit a 22mm pin. I just bought a set today along with a set of mahle 4032 2g/evo 9:1 stroker pistons. 2.3L build is coming together.


tektic
(Senior Member)
12/28/14 06:26 PM
Re: What pistons and what rods?

Evo head volume - 43cc
2G head volume -- 47cc
1G head volume -- 49cc

So when you say "2g/evo 9:1 stroker pistons" which is it 9:1 on a 2g or 9:1 on an evo.
Just something to think about before you start it up.


mitsuturbo
(Banthony )
12/28/14 06:52 PM
Re: What pistons and what rods?

I've cc'd a few 1g heads and they've all been 47cc.

mitsuturbo
(Banthony )
12/28/14 07:44 PM
Re: What pistons and what rods?

Mahle seems to think the evo has a 47cc head as well. At least that's what's in the catalog. I'll be close enough to 9:1 for me.


tektic
(Senior Member)
12/28/14 11:08 PM
Re: What pistons and what rods?

I agree that the 1g heads were 47cc also.

I ran the numbers with a calculator
Bore: 85.5mm .02" over
Stroke: 88mm
HG Bore: 86.3mm Mitsubishi MLS
HG Thickness: 1.3 Mitsubishi MLS
Piston Dome: -10cc
Head volume: 43cc / 47cc
------------------------------------
Comp Ratio: 8.82:1 / 9.33:1

Obviously if your head and block have been resurfaced it's higher, and also if your more than .02 over or running over sized valves.

I wish someone brought all that to my attention. Assuming a 47cc head my last engine specs out to 9.58:1. However I have 1mm over valves and both the block and head have been cut.

I'm using a 86mm piston with a -9cc dome and 94mm stroke. I should cc my head before I put it back together.


362Ryan
(Not Newbie)
12/29/14 12:30 PM
Re: What pistons and what rods?

Quoting EMX5636:

Quoting 362Ryan:

I'm with Biglady on this one.

I went with Wiseco HD's, tool steel wrist pins and K1 rods.

The machinist said the rods were some of the toughest he has worked with.




Not trying to divert too much off topic, but everything I've seen about K1 is they are the same as Eagle/Scat.




Where did you get that from? Because if you were to ask Tom Molnar, he would tell you that in his 30 plus years of designing rods for Oliver and K1 he hasn't borrowed an idea from them.
Let alone the fact the K1's are billet which to my knowledge is not available in Eagle or Scat.


89Patches
(I <3 AMS)
12/29/14 04:20 PM
Re: What pistons and what rods?

Manley, Eagle, Scat, K1 all get the rod blank's from the same place in China. Only difference is how each company machines them once in they're possession.

Sounds like your machinist is just telling ya what you wanna hear...


slugsgomoo
(god hates stupid people)
12/29/14 04:58 PM
Re: What pistons and what rods?

Quoting 89Patches:

Manley, Eagle, Scat, K1 all get the rod blank's from the same place in China. Only difference is how each company machines them once in they're possession.

Sounds like your machinist is just telling ya what you wanna hear...






362Ryan
(Not Newbie)
12/29/14 10:27 PM
Re: What pistons and what rods?

Quoting 89Patches:

Manley, Eagle, Scat, K1 all get the rod blank's from the same place in China. Only difference is how each company machines them once in they're possession.

Sounds like your machinist is just telling ya what you wanna hear...




Ahh yes. That must be it.



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