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1993 geo metro bottom end...; Wasted a rod bearing. What is the best bottom end rebuild?
Topic Started: May 20 2013, 11:37 PM (4,115 Views)
Spookum
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Hello, nice to meet you all. I'm a big fan and admirer. I have adapted a P-85 Polaris snow mobile CVT clutch to a geo metro motor. I'm using this in an Argo... Here is the link to the Argo forum.

http://www.6x6world.com/forums/argo-atvs/22921-master-build-thread-k-i-t-t-but-aplicable-all-others.html

Now I'm sure everyone is wondering wtf? I think the engine is plenty powerfull enough as it is. My question is this, how can I economically build a strong bottom end (and engine) that can see continuous duty up around 5000 rpm? The other point is that the engine will never see many miles again.... Argos do not have suspensions. 5000 miles in a Argo during its life time is a bunch!

Thanks guys!

Ps I drug it out of a junk yard with a seized engine.... So that could be cause/ effect for mauled rod bearing. I can also make the ticking/knock/rattle go away by pulling the spark plug closest to the trans.
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Geo Glenn
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What's in your engine?

Hello Spookum.

How many hours of operations do you expect your G10 engine to last before overhaul?

Is this something you'll be operating on a daily basis, or one of those black hole for money fun kind of things?
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allmountain40
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Stock bottom end should be sufficient. 3TECH once posted stock bottom end is sufficient for 200 HP. I shift mine routinely at 6200 rpm and am very hard on it and have never lost a bottom end.
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Spookum
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Geo Glenn
May 21 2013, 12:11 AM
Hello Spookum.

How many hours of operations do you expect your G10 engine to last before overhaul?

Is this something you'll be operating on a daily basis, or one of those black hole for money fun kind of things?
Yes sir, it is a "toy" used for camping/ hunting and traveling to remote places. I think that with stainlesss steel Valves it should go minimum 500 hours till it needs a rebuild but I would like to see it make a 1000 hours. But that is my humble opinion.... How ever I don't think it Merritt's fist fulls of money. A stock rebuild shoud be sufficient? Does anyone see any point in having the bottom end ballanced?

It had 150k miles on it when I pulled it (I think) and 135 lbs of compression.

Anything at all done to that motor u shift at 6200 rpm buddy? It is it a totally stock bottom end? Or did u have it ballenced? I know I got the rarity, a geo with a tired bottom end.

Just to give you guys an idea

Raw u tube link to me driving the Argo- metro!
http://www.youtube.com/watch?v=4slRGqQTkQE&feature=plcp


Thanks again for your help guys!!!!
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Papa_G
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:rocker That is so cool!
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j63812f
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J R

I have a crank KIT complete with oversized bearings that I would like to find a home for..........also have three oversized pistons and rings too, all came from a motor with 3000 miles on it...... but would allow you to rebuild like new for LOW cost. PM if interested,.

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Edited by j63812f, May 21 2013, 03:41 PM.
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Spookum
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j63812f
May 21 2013, 03:25 PM
I have a crank KIT complete with oversized bearings that I would like to find a home for..........also have three oversized pistons and rings too, all came from a motor with 3000 miles on it...... but would allow you to rebuild like new for LOW cost. PM if interested,.

Posted Image
Thanks buddy ill keep you in mind. Please remember to calculate in shipping to fairbanks, Alaska. Give me a pm with your price and ill see if it is just cheaper to machine the crank I got or go with yours.
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j63812f
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J R

i missed that part lol

Most of the mainstream auto parts sites offer crank kits and not too expensive.
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Spookum
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Many thanks for the crank offer friend.

So mr geo Glenn, and others, how would you build it budget minded? What about screw the budget, lets have something cool. Again, 58 hp is TRIPPLE the normal horsepower I need. It would be cool to have it sustain "higher" cruising rpm say 3500 rpm constant and 5000 sustained over longish distance? Do I need solid lifters????? Seems like the stock bottom end is solid.... Higher pressure oil pump?

Thanks in advance for your help!
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clarkdw
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Stock bottom end is fine for what you want. Stock hydraulic lifters and the 3Tech 222/365 cam like I have in my convertible is easily good for 7k rpm where factory fuel cut-off occurs. Even the stock factory cam will pull to 7k. It is just running out of steam as it gets above about 5500.

Edit: Stock oil pump is more than adequate. It is used in the 1.3 GT engine as well and that revs very high.
Edited by clarkdw, May 22 2013, 02:20 PM.
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Spookum
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Thanks for the advice. Any more anyone?
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nemoskull
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ill thow in my 2 cents.
sustained rpm above 3500 is probley not a good idea. oil pump (on a mark i) maxes out at 42 psi.
on a mostly rebuilt motor, i see 45 psi at 5500 rpm. i see 42 psi at 4500 rpm.
generally you want 10 psi for every 1000 rpm, so i would hesitate to run constant rpm above 4000. (i run 4000 most of the way on the free way. i drive fast :D)

edit again:
i would not know if u need to ballence the rotation assembly. as is, its a pretty bumpy motor, just the nature of a 3 cyl (one ignition every 240 degree)
some where about the 4500 - 6000 mark the motor has a natural ossilation. it show up and is taken up (me thinks) by the alternator bracket.
use good motor mounts for sure. i would not worry very much about it unless its airborne.
Edited by nemoskull, May 25 2013, 05:07 PM.
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Geo Glenn
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What's in your engine?

Fairbanks, Alaska.

Start at the coast, and drive North. I saw a bit about the winter snow removal on the highway. Totally amazing. Those plow drivers don't really need to look out the windshield. GPS navigation all the way.

Anyway . . .

"Mrs. Geo Glenn" got a short block that I built in her car a couple of weeks ago. The standard crankshaft was polished, and I matched a good used set of main and rod bearings to get tight new clearances. The pistons and rods were balanced to 0.1 grams. It has around 1,500 miles on it already. So far, it has made it up the 6% grades on Mt. Shasta in 4th gear at 55 MPH at wide open throttle. You could hear the engine hum, but no complaints. I caught a glimpse of her 2nd to 3rd gear shift entering the Interstate one time. 6,000 RPM's. Nice and smooth.

I'm not so worried about the bottom end of the G10 engine running at 5,000 RPM all day. The rings might not last so long, but if you're converting fossil fuel into fun, no worries, unless it's in the middle of the winter, and you have to walk.

I build engines to tight new limits. These engines go into passenger vehicles and the owners drive very conservatively to get good gas mileage. There's a group of guys in the world who race with the G10/G13 engines. I'm not sure about the clearances on their builds. My machine shop guy builds a lot of engines that produce several hundred HP. They typically set the rod bearing clearances 0.0005" larger than standard. I'm not sure what they do with the piston to wall clearances. Someone who's more familiar with the racing side of Suzuki world can chime in on this.

Regardless of the build clearances, you will want a good set of parts to work with. With those in hand, your machine shop can grind to clearances that you figure will work.

I'm setting piston to wall clearances at 0.0008" to 0.0009". I'm pretty sure that somewhere around 0.0015" piston to wall clearance you will have excessive crankcase pressure. Perhaps 0.0010" - 0.0012" piston to wall clearance will work for a sustained power output. The top compression ring gap will probably be in the 0.009" - 0.012" range.

I found that the 0.010" oversize connecting rod bearings work best with a good crush if I have them resized to 1.7712". The 0.010" oversize rod bearings from Taiho and King all measure 0.0632", and sometimes 0.0633". I have the crankshaft grinder set 0.0010" clearance on the crank to bearings. Something closer to the upper limit of new might work better, perhaps 0.0015" to 0.0018". Put the bearings in the rods and case, and have the crankshaft ground to spec.

A good used engine, on the economy side, might cost you $300. If it looks clean inside, and has the factory hone marks still visible in the cylinders, you can most likely install a set of EVE standard size piston rings and a fresh head that's professionally reworked and be up and running for under $500. You might not ever have to do rings. If it's a running engine, that has good compression and low oil consumption, a paint and gasket overhaul is all that will need to be done. I've done a couple of paint and gasket overhauls. You have to start with an engine that's pretty clean inside. 1/4" of sludge in the bottom of the oil pan is a bad sign. 1/4" of sludge on the top of the head under the valve cover is a bad sign.

A full meal deal, balanced and blueprinted engine build is likely to cost around $1,100 or more in parts and machine shop labor. You can have all the right parts available, but unless the machine shop understands what clearances you want, you'll be putting together a brand new worn out engine.

GG
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Spookum
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Thank you guys! I know there is a bad bearing In The bottom end probbabaly a rod bewring. The compression is at 134 135 130.... Just rings there I hope.... And hone it! Put stainless steel exhaust va es in the head.... Check intake valves. New valve seals...

Grind the crank to .0015... Is that the crank bearings only? What about rod bearing tollerences? (Hope that isn't too bad of a noob question)

I don't think that I have to go crazy here.... The vehicle is belt drive and 1500 lbs! It should fly when I'm done!
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Geo Glenn
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What's in your engine?

The best thing to do is to disassemble the engine and inspect it prior to buying any parts.

The OEM exhaust valves are stainless steel, as well as every aftermarket exhaust valve that I have ever seen. If the valves are not burned, you can have them reground as part of the service you get at a machine shop.

If your crankshaft needs to be ground, the best way to get the desired clearance is to install the new oversize bearings in the engine case and the connecting rods and have the crankshaft grinder measure the bore, and grind the crank to spec.

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