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1G Does my engine need to be balance?

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96talonchick

Proven Member
202
10
Feb 3, 2016
Chippewa Falls, Wisconsin
Sorry if this has been perviously asked.

I am doing a 1g swap and was wondering if my engine will need to be balanced. Internals are being replaced with Weisco forged pistons 0.020 over, Eagle H beam rods, factory crank that was tuned 0.25.
 
It's a good idea if everything's out.. By going forged, you're already investing in the bottom end, it just depends on how far you want to go with the balancing.
Most people don't balance the flywheel, for instance, but they will balance the rods within a gram or so of each other and the crank to less than that. If the crank had to be cut that much, I'd definitely get it fluxed and the fillets checked for spec if it wasn't already.
 
My engine is currently at the machine shop, it was bored, added weisco pistons, eagle rods and the balance shafts are being removed as well. Crank was turned and flywheel was surfaced. Got arp studs all the way around and will be using a main girdle too. The machinist will be doing a line hone if it's not within specs.

Being that nothing is factory anymore my biggest question was in regards to engine balance and if it needed to be done or if it's going to still be within spec.
 
I think? My husband is not a dsm guy at all, his toy is his foxbody mustang. He had mentioned that his car would need to be "balanced" after all these changes and now I'm wondering if I am going to need to as well. Now I myself am a complete noob with this car or any car for that fact, but I've been taking the initiative and wrenching along side my husband since it is my car and not his. Which is why I am now turning to a forum to ask questions. My machinist is unable to do any balance work at his location and it would need to be sent out, which adds to my cost. So if I can safely drive my boosted car w/o it being balanced it frees up some money to be put elsewhere in it.
 
It's never a bad idea to have it done. When they cut the crank did they check it for straightness?
Since you've gone all forged, except for the crank, what are your power goals? Are you also expecting to rev it above 6 or 7k? Did you also get headwork done (new valve springs, etc.)?
 
It's never a bad idea to have it done. When they cut the crank did they check it for straightness?
Since you've gone all forged, except for the crank, what are your power goals? Are you also expecting to rev it above 6 or 7k? Did you also get headwork done (new valve springs, etc.)?

My power goals now are different than my end goal. Right now I want to drive my car, I bought it broken and it needed more work than was expected. The head was rebuilt by the person I bought it from but he couldn't get it to start. Which is how I ended up with it, the machinist took the head apart and checked it out, only recommendation he had was to replace the valve guides as they had some play.
As far as a Rev point, I have no idea. I do not know where the power points will be until I get to drive it. My stock esi I also own is 6k max and then it's a waste after that.

I do plan on putting a 14b turbo on it (mine was broke when we got the car) until next winter. Then I intend to build the head and upgrade turbos. Ultimate end goal is to keep up to my husband's mustang at the track, he runs a 12.8, shooting for a 12.5 this summer.

I will be calling my machinist about the crank yet today, I do believe they checked it out. It wasn't cracked but had some bearing damage done to it. Every bearing in my block was trashed, shavings did a number on the internals, which is why I went in depth with the build. Pointless to replace with factory parts if better is a slightly more expensive.
 
Oem cranks are cheap on the forums and you don't really need to replace them with any aftermarket ones, at least not for your goals. And those goals as far as the stang. Are completely achievable. Your Max rev depends on your turbo because they need more volume, cams would also be beneficial. But if you plan on staying with OEM like turbos then you can eliminate alot of parts mostly to your valve train.

Good luck and post some pics when ever available.
 
maybe i am blind but i do not see mentioned, is this a gst or gsx?

taking that mustang to the cleaners will not be a problem for even a stock engine and a 14b. however if you are a GST traction WILL be a problem.

as for the engine, im not a fan of turning any crank, especially hardened ones. replace it with OEM or eagle. (if you get an eagle crank it will need balanced) balancing is nice but if your not building a high RPM build (8000rpm+) i would skip it. also leave the balance shafts in, ESPECIALLY if you are planning on running a light weight flywheel. (is your car manual or auto?) if you have not ordered the pistons yet i recommend NOT using the standard CR. you want at least 9:1 or 10:1, it will help off boost power and it will feel like it spools faster. especially if you plan on keeping the 14b or going 16g for a while.

dont worry about cams, there are gains to be had there but again, its money better used elsewhere for what you get.
 
Lots run a cut crank with no issue and no retreatment but I would be more weary of 0.025 than the "standard" 0.01. If it needed that much because of the bearing trashing, replacement may be preferable. I would at least get the crank *checked* for balance. I would not worry so much about the pistons and rods, but you could even check them yourself with a kitchen scale.
 
It is a manual 96 eagle tsi with a 6 bolt swap and a 99 gst ecm. I know traction will be an issue being that this is fwd.

As for the crank I called and checked today, it has been throughly taken care of. The machine shop I chose happens to be my employer, just a town over.

Here is the current parts list:
Wiseco Pistons / Mitsubishi 4G63 / 1988-92 6 Bolt DSM / 2.0l / 8.3:1 CR / 85.5mm +.020 Overbore

Eagle Connecting Rods / 6 Bolt DSM (22MM WRIST PIN)

Kiggly Racing 6 Bolt Main Girdle (2 Pieces)

King XP Series Main Bearings (4g63 6-Bolt) .25mm/.010"

King XP Series Rod Bearings (DSM/Evo) .25mm

ITM Oil Pump / 6 Bolt DSM

Also arp studs all the way around and the b/s elim kit.
 
I didn't realize you were meaning .25mm; should have considering you couldn't cut it .25in. Duh on me. Nice build, the crank will be fine if it is undamaged beyond the cleanup (cracking, warpage, bend, etc.) Enjoy!
 
one would think that balancing all the components would be part of and included into the price of the build when coming from an engine builder .
If I was having a shop build it yes, I am just having the shop do the needed machine work that we cannot do ourselves. Between myself and my husband we can put it together and tune it.
 
I see , sounds like a good time !! wish my wife liked cars and getting greasy, she likes shoes does that count ? bahahahahaha! I'm still thinking that the shop would still point you in that direction for balancing engine components and such.
 
I do know I have an option to get it balanced, would cost at extra $155 and it's an expense I'd do only if needed. I still have an expensive parts list to purchase and would much rather stick the saved money into buying the rest of what I need. But if being balanced was necessary, which it seems to not be from the majority of forum responses, then I'd so it to save myself an expensive failure in the future.
 
Ok your husband is right. A v-type motor relies on the weight of the pistons and rods to counteract the weight of the counterweights on the crank. Balancing a v type motor is different than a inline because there are 2 planes that the reciprocating weight moves in. The have to calculate a "bob" weight which is a certain percentage of the reciprocating weight/the counterweight. The put those on the crank and spin it, to balance it they adjust the counterweight. The engines are balanced from the factory, but for a certain weight rod and piston, and generally not to a very high tolerance or to a percentage that is the best for high rpm. If you change the weight of the rod and piston, you'll need to have it re-balanced. You also have to make sure that all the pistons, little of the rods, big ends of the rods match.

On an inline 4 it's much different All the weight moves in the same plane, and the pistons going up, mostly counteract the pistons going down. On a 4cyl there is no bob weight, you just need to make sure that all the rods match, and the pistons match in weight. The crank will already be balanced, it just might not be to a very high tolerance. I've had ones that needed very little material removed, and I've had ones we had to weld on.

the damper has nothing to do with balance on a 4g, or any other neutral balance motor for that matter. Every time the engine fires the crank rings like a tuning fork - oscillating back and forth a tenth of a degree or so. Some cases the the firings sync up with the oscillations, and they will grow in magnitude. left unchecked this with fatigue and break the crank off at the snout. The damper "DAMPENS" these oscillations.

Next thing is balancer shafts - silent shafts actually. Near TDC the pistons going up do not have the same acceleration and the pistons going down. This results in a net force on the engine. The silent shafts counteract this. They have nothing to do with the actual balance of the engine.

Lastly is line bore. If your doing arp studs and a girdle this is probably more important than balancing. The arp studs provide more clamp load due to the higher torque value afforded by the higher yield strength material they are made of. This additional clamp load will distort the main bearing bores by .001 or more, making them not round anymore, possibly not even inline any more. That's bad for bearings. For your purposes you would probably be best with stock mainbolts and no girdle. Those start becoming a need when your after 600whp or more.
These motors are very tough in stock form, you really don't need to throw a bunch of stuff at it for no reason.
 
Thank you for the replies, you have all helped me out. Once I figure out how to add a pic to my profile I shall, still trying to navigate the site. Thanks for the help! I am sure I will have many more questions.

Lastly, if anyone knows of a 14b or 16g turbo for sale Id love to hear about it. I have 1 wk left before I purchase a turbo and I haven't seen much in the classifieds.
 
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