4g61t.org :: Rods and Pistons

I know the 1G rods have held 450+ HP but should i really upgrade teh rods to say some Eagle H-beams or stick with the stock rods and get some good pistons I'm going to overbore the motor to 85mm

Why do you want to bore your motor? Stick with the stock stuff at low compression and run a ton of boost. You'll need to since mitsus head design sucks. Stock motors can handle a ton of power so I really see no need to change anything unless you start making rediculous power.

I'm sorry to get into it with you but I believe that you are completely wrong on your theory of ( MITSUS HEADS SUCK)... worst statement ive ever heard...

Quote:

I'm sorry to get into it with you but I believe that you are completely wrong on your theory of ( MITSUS HEADS SUCK)... worst statement ive ever heard...

Compared to civic si heads/cams Mitsus design does suck. Those heads have a much more straight port design to the valve than mitsus heads and the cams on the high lobe have a much faster ramp rate, similar to an X grind from FP at worst. Think about why hondas can run 10psi of boost on the same turbo as where we have to run 20psi to achieve the same power numbers. Its all in the head/cam design and the bore/stroke combo. The bore/stroke combo does play a decent part as well on the hondas. I can verify all this info with sources if need be. Your turn.

You'r really not counting the compression ratio's also play a huge role...but your correct the stock cam's in vtec honda head are larger...but only when vtec is engaged. Throw some 272's in a mitsu head and it will flow just as much. When it comes to port size the mitsu's flow as good as any...cam and valve differences are easily fixed. If you want to talk about a lacking head, look at a SR20.

Author:	chdesign [ Thu Nov 17, 2005 7:41 pm ]
Post subject:	Rods and Pistons
Hey guys I am 99.9% sure I've read that the 1G big rods are the same rods in our 4G61T same part number everything can someone please verify this before I order a set of rods for my motor build. Also does anyone know if there are some forged pistons anywhere available for the 4G61T or am I stuck on the custom forged route. Any help appriciated.

Author:	dragstr4g61t [ Thu Nov 17, 2005 8:03 pm ]
Post subject:
rods are identical and with such a short stroke they will handle all the power you throw at them. any 1G aftermarket rod will work if your looking for lighter weight options.

Author:	chdesign [ Thu Nov 17, 2005 8:07 pm ]
Post subject:
I know the 1G rods have held 450+ HP but should i really upgrade teh rods to say some Eagle H-beams or stick with the stock rods and get some good pistons I'm going to overbore the motor to 85mm

Author:	redrum123 [ Thu Nov 17, 2005 8:36 pm ]
Post subject:
Quote: I know the 1G rods have held 450+ HP but should i really upgrade teh rods to say some Eagle H-beams or stick with the stock rods and get some good pistons I'm going to overbore the motor to 85mm People have run 600+ hp on the stock 1g rods, but the low 7.8:1 compression of a 1g motor is kinda lacking... your best bet would be to spend the extra 300 bucks to run eagle H beam rods that have handled TONS of horsepower and stick them on 2g pistons. ( very strong pistons) on a stock 2g dsm bottom end with ONLY headstuds my car ran a 11.949 at 120MPH, dont underestimate the power of the 4g61/63t there great motors

Author:	chdesign [ Thu Nov 17, 2005 8:48 pm ]
Post subject:
well i can't run 2g pisotns in the 61T as the pin to piston height is different due to the higher deck height of the 63 block. So custom pistons are my only key i believe.

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Rods and Pistons http://4g61t.org/forum/viewtopic.php?f=6&t=15861	Page 1 of 2

Author:	SpinMasta11 [ Thu Nov 17, 2005 11:14 pm ]
Post subject:
Why do you want to bore your motor? Stick with the stock stuff at low compression and run a ton of boost. You'll need to since mitsus head design sucks. Stock motors can handle a ton of power so I really see no need to change anything unless you start making rediculous power.

Author:	xlr8 [ Thu Nov 17, 2005 11:45 pm ]
Post subject:
Im running 85.5mm pistons from memory. In any case it equates to 1.75L or ~150cc more capacity which is nothing to sneeze at and is worthwhile. The flat-top pistons in my 4G61T are cast hyper-eutectic items that are in fact machined down from an aftermarket 4G64 domed NA piston (with due consideration to crown thickness). Since machining the piston creates stress-risers in the metal the piston must be re-normalised. Instead I had the pistons HPC treated with moly side skirts and ceramic crowns. The hi-temp baking process for the coatings normalises the pistons at the same time. As I remember it cost me about AUS$350 for the pistons and rings, $200 in HPC coating and $50 in machining labour. The result I ended up with is essentially a ~8.5:1 CR hyper-eutectic piston which is the rough 4G61 equivalent of a 4G63 2G piston. The stock 1G rods are forged stock. You can get them shot-peened for a little bit of extra reliability.

Author:	redrum123 [ Fri Nov 18, 2005 2:33 am ]
Post subject:
Quote: Why do you want to bore your motor? Stick with the stock stuff at low compression and run a ton of boost. You'll need to since mitsus head design sucks. Stock motors can handle a ton of power so I really see no need to change anything unless you start making rediculous power. I'm sorry to get into it with you but I believe that you are completely wrong on your theory of ( MITSUS HEADS SUCK)... worst statement ive ever heard... i have run a 11.949 on a 2g dsm with a stock head stock cams and a stock intake manifold, pushing around 460 to the wheels... The mitsu heads compared to a honda head, camaro heads are rediculous, your statement needs some research put behind it because you are completely wrong....

Author:	redrum123 [ Fri Nov 18, 2005 2:37 am ]
Post subject:
and im sorry i dont want to sound harsh

Author:	BitAddict [ Fri Nov 18, 2005 5:44 pm ]
Post subject:
Im also looking to go with a good 1g rod/2g piston combo for my current 4g63t build. I know ebay is not exactly the place to go for these parts but these two links are for what i am looking for... http://cgi.ebay.com/ebaymotors/MITSUBIS ... enameZWDVW http://cgi.ebay.com/ebaymotors/Mitsubis ... enameZWDVW Does the quality seem to be there. Any opinions? Or should Myself(and others) stick with a know dsm shop like slowboy? -Bit (didn't mean to hijack the thread but im in a parallel situation)

Author:	waxie1 [ Sun Nov 20, 2005 6:13 am ]
Post subject:
I'm using those eBay pistons and so far have had no probs... I've had them in for almost a year now, with standard boost. The pistons look identical to the original. If you do end up using 2G's on 1G rods check this post.... http://www.4g61t.org/phpBB2/viewtopic.php?t=15103

Author:	coltTSI [ Sun Nov 20, 2005 12:25 pm ]
Post subject:
I have 1G eagle rods and 2G Ross Racing Pistons and never had problems. I prefer a full floating set-up. Also you can do some research about the other pistons cause they don't have the same wall to piston clearance. JE and Wiseco need less clearance etc... There are shops that stopped putting certain brands of pistons in their engine due to problems they had with that clearance. Everything depends on your set-up and how much rubber you wanna burn...

Author:	SpinMasta11 [ Wed Nov 23, 2005 9:39 pm ]
Post subject:
Quote: I'm sorry to get into it with you but I believe that you are completely wrong on your theory of ( MITSUS HEADS SUCK)... worst statement ive ever heard... Compared to civic si heads/cams Mitsus design does suck. Those heads have a much more straight port design to the valve than mitsus heads and the cams on the high lobe have a much faster ramp rate, similar to an X grind from FP at worst. Think about why hondas can run 10psi of boost on the same turbo as where we have to run 20psi to achieve the same power numbers. Its all in the head/cam design and the bore/stroke combo. The bore/stroke combo does play a decent part as well on the hondas. I can verify all this info with sources if need be. Your turn.

Author:	dragstr4g61t [ Fri Nov 25, 2005 10:45 pm ]
Post subject:
Quote: Quote: I'm sorry to get into it with you but I believe that you are completely wrong on your theory of ( MITSUS HEADS SUCK)... worst statement ive ever heard... Compared to civic si heads/cams Mitsus design does suck. Those heads have a much more straight port design to the valve than mitsus heads and the cams on the high lobe have a much faster ramp rate, similar to an X grind from FP at worst. Think about why hondas can run 10psi of boost on the same turbo as where we have to run 20psi to achieve the same power numbers. Its all in the head/cam design and the bore/stroke combo. The bore/stroke combo does play a decent part as well on the hondas. I can verify all this info with sources if need be. Your turn. You'r really not counting the compression ratio's also play a huge role...but your correct the stock cam's in vtec honda head are larger...but only when vtec is engaged. Throw some 272's in a mitsu head and it will flow just as much. When it comes to port size the mitsu's flow as good as any...cam and valve differences are easily fixed. If you want to talk about a lacking head, look at a SR20.

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Author:	SpinMasta11 [ Sat Nov 26, 2005 7:43 pm ]
Post subject:
Quote: You'r really not counting the compression ratio's also play a huge role...but your correct the stock cam's in vtec honda head are larger...but only when vtec is engaged. Throw some 272's in a mitsu head and it will flow just as much. When it comes to port size the mitsu's flow as good as any...cam and valve differences are easily fixed. If you want to talk about a lacking head, look at a SR20. Do a compression check on a honda while clicking over the vtec selonoid and let me know what it comes out to be, I think you'll be very very surprised. GSR cams are much more aggresive than Si cams also, and thats what a lot of your turbo guys run if they can't get their hands on ITR cams. You are right that the mitsu head does flow well with upgraded cams but stock for stock compared to a honda its not even close. 1g heads are worthless to even port really. It may increase flow but for some reason it doesn't do much in terms of dropping ETs. A buddy of mine just got rid of his stage IV BJs head and went back to a stock head. Trapped 4mph higher and that was the only change he made on the car. I totally agree that if you throw on a good intake manifold and a good set of cams that you can get the mitsus to flow decent but that still doesn't explain why hondas have the ability to make such good power at low boost levels compared to mitsus. Bore being > stroker also does a few things to help out the hondas in certain cases.