Author Topic: Is one crank as good as another (Read 5966 times)

Roach Carver · « **on:** February 07, 2016, 07:38:16 PM »

Here's my problem. I'm building a guzzi for my wife. It's a v700 with an ambo engine. I ordered the replacement cylinders because I'm a loving husband. Went to install and realized one rod was very tight on the crank. Bearing was galled but crank is "fair". Rod on the little end has a bit of play. I have an 850 crank and rods. Should I tear it down or are they different parts altogether. Thanks! Also any Ducati experts or amateurs here? I have a 1975 860 gt with ignition problems.😉

Roach Carver · « **Reply #1 on:** February 07, 2016, 07:48:42 PM »

Antietam Classic Cycle · « **Reply #2 on:** February 07, 2016, 08:01:12 PM »

Quote from: Roach Carver on February 07, 2016, 07:38:16 PM

Here's my problem. I'm building a guzzi for my wife. It's a v700 with an ambo engine. I ordered the replacement cylinders because I'm a loving husband. Went to install and realized one rod was very tight on the crank. Bearing was galled but crank is "fair". Rod on the little end has a bit of play. I have an 850 crank and rods. Should I tear it down or are they different parts altogether. Thanks! Also any Ducati experts or amateurs here? I have a 1975 860 gt with ignition problems.😉

The 850 crank has a 78 mm stroke and won't work with Ambassador pistons.

Roach Carver · « **Reply #3 on:** February 07, 2016, 08:08:16 PM »

Thanks. I figured it was a long shot

Wildguzzi.com · « **Reply #3 on:** February 07, 2016, 08:08:16 PM »

oldbike54 · « **Reply #4 on:** February 07, 2016, 08:10:11 PM »

Hi Brad

Dusty

Roach Carver · « **Reply #5 on:** February 07, 2016, 08:23:58 PM »

Hey Dusty! I keep reading about the camp out. Me and the wife have to make it some time.

mtiberio · « **Reply #6 on:** February 07, 2016, 08:37:13 PM »

Grind the crank. Bush the rods

Antietam Classic Cycle · « **Reply #7 on:** February 07, 2016, 08:41:46 PM »

Quote from: mtiberio on February 07, 2016, 08:37:13 PM

Grind the crank. Bush the rods

Roach Carver · « **Reply #8 on:** February 27, 2016, 09:22:30 AM »

Cranks out. Found a lot of non factory bolts, crap washers and other things that lead me to believe someone has been into this thing already. One thing I noticed was a good bit of play from front to back on the crank with the front and rear bearing in place. Is this normal? Or did the previous guy omit some shims or something to control the end play.

canuck750 · « **Reply #9 on:** February 27, 2016, 09:28:10 AM »

Even after a regrind with new crank bearings and big end rod shells there is a lot of end play, once the flywheel and clutch are bolted on, timing gears et all, it will be fine.

Roach Carver · « **Reply #10 on:** February 27, 2016, 09:38:53 AM »

Thanks! I've never seen anything that loose 😀

oldbike54 · « **Reply #11 on:** February 27, 2016, 09:40:59 AM »

Deuce , you had better hurry up , we want to see that thing at Cedar Vale

Dusty

Antietam Classic Cycle · « **Reply #12 on:** February 27, 2016, 09:43:28 AM »

Quote from: Roach Carver on February 27, 2016, 09:22:30 AM

One thing I noticed was a good bit of play from front to back on the crank with the front and rear bearing in place. Is this normal? Or did the previous guy omit some shims or something to control the end play.

Crank end float is controlled by the crank sprocket. It must be on and torqued to spec. before end float is checked. Same with the cam - the sprocket must be on and tightened down.

Roach Carver · « **Reply #13 on:** February 27, 2016, 09:50:56 AM »

Thanks Charlie!!

Roach Carver · « **Reply #14 on:** February 27, 2016, 10:20:00 AM »

Is there a preferred machine shop in the Arkansas Missouri area to turn this crank?

oldbike54 · « **Reply #15 on:** February 27, 2016, 10:35:12 AM »

Quote from: Roach Carver on February 27, 2016, 10:20:00 AM

Is there a preferred machine shop in the Arkansas Missouri area to turn this crank?

You might contact NWA Streetworks in Siloam and ask them . Shouldn't be anything tricky about turning a ditch pump crank . Oh , maybe the boys at Bentonville BMW could recommend a machinist.

Dusty

Roach Carver · « **Reply #16 on:** February 27, 2016, 10:37:13 AM »

I've used Paul's machine shop in Springdale before but they are far from a motorcycle centric machine shop. More of an anything goes machine shop. Thanks Dusty.

bmc5733946 · « **Reply #17 on:** February 27, 2016, 04:52:50 PM »

Any qualified crank grinder can grind a Guzzi crank. A qualified crank grinder is one who has ground a crank previously, can read and follow instructions etc. Critical areas on Guzzi cranks are the fillet radii at the crankpin, crank weight juncture. You must supply this information and the grind diameter from the appropriate service manual. The fillets are critical, if needs be you do the math for those incapable of using the metric system of measurement. Please do not ask how I came to know these things, it was very expensive!!

Brian

Roach Carver · « **Reply #18 on:** February 29, 2016, 09:46:38 AM »

I am sending the crank and rods to Harper's for eval and machining. I am curious what 850 parts are interchangeable. I have an 850 parts motor. My concern is the 750 cam looks to have a good bit of wear too so I would like to know if I can use the block and cam from the 850. The 750 block has some noticeable wear on the cam journals in the block. I think the oil pump is interchangeable so I am going to look at that as well. I think this all went south when some moron glopped ultra copper all over the pan gasket. Thanks

Antietam Classic Cycle · « **Reply #19 on:** February 29, 2016, 10:00:10 AM »

An 850 gear-driven-cam case would be directly interchangeable with the Ambassador case, if a later chain-driven-cam case, the oil pump location is slightly different. Chain drive started with (Eldorado) engine number 58532.

Also, the hole for the distributor base is larger on the 850 case - you'd need the Eldo distributor base or to fit a reducer ring like Guzzi did on the last of the Ambassadors.

Roach Carver · « **Reply #20 on:** February 29, 2016, 11:47:50 AM »

Thanks Charlie!

bigbikerrick · « **Reply #21 on:** February 29, 2016, 04:03:47 PM »

Charlie, It never ceases to amaze me what a wealth of loop frame knowledge you are! I see how you are eager to humbly help people on a daily basis, with accurate, correct information, and that is awesome. I think back to years ago, when I was asking.... dumb questions like "do I really have to change out my chrome bores, when some folks have run them over 100K miles" ....you have the patience to take the time , and explain everything, options available, and useful links, etc. I dont see how you do it sometimes....
I've seen this over, and over again,you helping new guys, never being sarcastic, or with an annoyed "tone" in any way.
My hat is off to you, Charlie! I just want to take this opportunity to thank you, you are a first class assett to the Guzzi community!

Rick.

Antietam Classic Cycle · « **Reply #22 on:** February 29, 2016, 04:38:37 PM »

Thank you for the kind words, Rick. I try to help where I can. Probably spend much more time than I should on various forums doing so, but it all seems to come back to me as "good karma". Many here have helped me with advice, sent me parts, etc., so it's just my way of "paying it forward".

Roach Carver · « **Reply #23 on:** March 14, 2016, 10:20:20 AM »

Well, here's where I am at. I think I have a good 850 block. Cam and lifters looked good out of donor motor. I bought an extra set of rods and sent crank and rods up to Harper's Moto guzzi for evaluation last week. I just spoke with Curtis today and hopefully they will have them checked out in the next day or two. I'm am chomping at the bit to get this thing back together. Riding season is here...

jbell · « **Reply #24 on:** March 15, 2016, 09:58:47 PM »

I'm nowhere near expert status, but do have a running '75 860GT. What's going on with yours?

Sasquatch Jim · « **Reply #25 on:** March 15, 2016, 10:23:42 PM »

I am probably just as good as any other crank on this forum.

Roach Carver · « **Reply #26 on:** March 16, 2016, 07:54:28 AM »

Quote from: jbell on March 15, 2016, 09:58:47 PM

I'm nowhere near expert status, but do have a running '75 860GT. What's going on with yours?

Well looks like I am going through the whole motor but I think I am in the right track. Just going to keep throwing money at it until I can't afford to sell it.

Roach Carver · « **Reply #27 on:** March 16, 2016, 07:55:54 AM »

Quote from: oldbike54 on March 15, 2016, 11:27:47 PM

No truer statement ever

Hurry up Deuce , promised the Cedar Vale bunch you would make an appearance on this thing along with Uno on his er , unrestored loop

Dusty

I am counting it down in hopes that I can make it. Between this bike and the Ducati I am working on I am getting my rear handed to me.

jbell · « **Reply #28 on:** March 16, 2016, 07:59:29 PM »

Quote from: Roach Carver on March 16, 2016, 07:54:28 AM

Well looks like I am going through the whole motor but I think I am in the right track. Just going to keep throwing money at it until I can't afford to sell it.

Well, with the 860 GT, it won't take much to reach that threshold. Of all the Ducatis in all the world, our 860's seem the least loved.

canuck750 · « **Reply #29 on:** March 16, 2016, 08:08:57 PM »

Quote from: Roach Carver on March 16, 2016, 07:54:28 AM

Well looks like I am going through the whole motor but I think I am in the right track. Just going to keep throwing money at it until I can't afford to sell it.

Does that ever sound familiar!

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Author Topic: Is one crank as good as another (Read 5966 times)

Wildguzzi.com

oldbike54

canuck750

oldbike54

oldbike54

canuck750