Motor is tight when turning by hand |
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Motor is tight when turning by hand |
swood |
Nov 6 2004, 10:14 PM
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#1
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Senior Member Group: Members Posts: 1,839 Joined: 6-February 03 From: Strong Beach Member No.: 251 Region Association: None |
Ok, I've finally cut the p-rods and am loading them in and adjusting the valves. Right now it's on TDC for #1. I notice that when I turn the flywheel, at some point in the rotation there is a little tightness for a few degrees, maybe a 1/4 turn or so. My jugs were opened to 96mm with new KB's and hastings rings. Could this be just the rings on one of the pistons when down low in the cylinder? I don't know how free a new motor is to turn. The crank turned smooth as silk before connecting the rods, p&c's etc.
My hands hurt from the teeth on the flywheel so any thoughts would be great. |
Aaron Cox |
Nov 6 2004, 10:32 PM
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#2
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Professional Lawn Dart Group: Retired Admin Posts: 24,541 Joined: 1-February 03 From: OC Member No.: 219 Region Association: Southern California |
is it called compression? (IMG:style_emoticons/default/laugh.gif)
PS- next sat fun run. youre invited. no isnt an answer (IMG:style_emoticons/default/biggrin.gif) |
swood |
Nov 6 2004, 10:35 PM
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#3
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Senior Member Group: Members Posts: 1,839 Joined: 6-February 03 From: Strong Beach Member No.: 251 Region Association: None |
uh-huh. No plugs in. Not compression. Next?
You'll have to take a no...this time. I'm on a mission to get this motor running an on the road by Xmas. baby steps...baby steps... |
Aaron Cox |
Nov 6 2004, 10:38 PM
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#4
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Professional Lawn Dart Group: Retired Admin Posts: 24,541 Joined: 1-February 03 From: OC Member No.: 219 Region Association: Southern California |
uh oh- i think somethings wrong then. jake says these motors hsould turn by hand... (IMG:style_emoticons/default/ohmy.gif)
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redshift |
Nov 6 2004, 10:40 PM
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#5
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Bless the Hell out of you! Group: Members Posts: 10,926 Joined: 29-June 03 Member No.: 869 |
Yeah, they should.... I know you have adjusted your own valves... and you know how that works..
=| M |
914GT |
Nov 6 2004, 10:40 PM
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#6
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Senior Member Group: Members Posts: 1,100 Joined: 11-October 04 From: Tucson Member No.: 2,923 Region Association: Southwest Region |
Did you notice it before tightening the valves? Did you have the rods off the crank?
(edit) never mind the second question. Did you fit the rods on the crank before installing them in the case, to check your clearances? |
swood |
Nov 6 2004, 10:58 PM
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#7
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Senior Member Group: Members Posts: 1,839 Joined: 6-February 03 From: Strong Beach Member No.: 251 Region Association: None |
QUOTE(914GT @ Nov 6 2004, 08:40 PM) Did you notice it before tightening the valves? Did you have the rods off the crank? (edit) never mind the second question. Did you fit the rods on the crank before installing them in the case, to check your clearances? Yipper. This is a complete rebuild. When I closed up the case, with rods attached to the crank, with the case sideways I could freely turn the crank by the rods. The tightness I'm referring to happens without the valve train installed. It is now though... I think there is something going on with either the pistons (they had enough skirt clearance when loaded) or the flywheel? I'm not sure what that would be. I did have the flywheel machined and I have the three shims in. and the little felt piece too. (IMG:style_emoticons/default/biggrin.gif) |
914GT |
Nov 6 2004, 11:08 PM
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#8
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Senior Member Group: Members Posts: 1,100 Joined: 11-October 04 From: Tucson Member No.: 2,923 Region Association: Southwest Region |
Yes, that's looking more like what you first suspected with the rings on one of the pistons. But why I don't know. Don't see why the flywheel would cause this.
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Zeke |
Nov 6 2004, 11:09 PM
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#9
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Never left, but not right.... Group: Members Posts: 382 Joined: 26-January 03 From: Long Beach CA Member No.: 197 Region Association: None |
There is a point when all 4 pistons are in mid stroke twice in each revolution. The drag of the new rings on the freshly honed cyls creates a pretty good resistance.
If it is doing this right after TDC and BDC on no. 1, it's normal. Did you assemble the P/C's dry like a lot of engine builders say to do? Aids in breaking in the rings. (of course, you shouldn't take advice from a guy who broke 2 motors in less than 5 laps at Willow Springs) (IMG:style_emoticons/default/sad.gif) |
swood |
Nov 6 2004, 11:13 PM
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#10
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Senior Member Group: Members Posts: 1,839 Joined: 6-February 03 From: Strong Beach Member No.: 251 Region Association: None |
Yeah Milt, that's how it feels. My instinct tells me to just fire the puppy up and get the rings broke in. I might want to start it up prior to installing it in the car. Just to save me a few steps if it fails at that point. I don't have to worry about the cam break in since I have the ceramic cam followers.
I've just been concerned that's all. |
Demick |
Nov 7 2004, 12:19 AM
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#11
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Ernie made me do it! Group: Benefactors Posts: 2,312 Joined: 6-February 03 From: Pleasanton, CA Member No.: 257 |
Did you measure and set the crank endplay with the appropriate flywheel shims? Could be to little thickness in those shims causing the endplay to be near-zero, which could cause the tightness you are feeling.
Demick |
swood |
Nov 7 2004, 12:52 AM
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#12
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Senior Member Group: Members Posts: 1,839 Joined: 6-February 03 From: Strong Beach Member No.: 251 Region Association: None |
QUOTE(Demick @ Nov 6 2004, 10:19 PM) Did you measure and set the crank endplay with the appropriate flywheel shims? Could be to little thickness in those shims causing the endplay to be near-zero, which could cause the tightness you are feeling. Demick Too little or too much thickness? Not sure what you mean. |
redshift |
Nov 7 2004, 12:53 AM
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#13
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Bless the Hell out of you! Group: Members Posts: 10,926 Joined: 29-June 03 Member No.: 869 |
Hey! Maybe it just needs to be revved to 10 grand once!
(IMG:style_emoticons/default/smile.gif) I imagine I would be to paranoid to EVER crank an engine I built. M |
swood |
Nov 7 2004, 01:01 AM
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#14
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Senior Member Group: Members Posts: 1,839 Joined: 6-February 03 From: Strong Beach Member No.: 251 Region Association: None |
Well then, where is the fun in finding out if you really can't rebuild an engine after all!! (IMG:style_emoticons/default/w00t.gif)
Nothing like a 5k firecracker. Thank you for your support. WOuld you like to buy some meat over the phone? |
swood |
Nov 7 2004, 01:04 AM
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#15
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Senior Member Group: Members Posts: 1,839 Joined: 6-February 03 From: Strong Beach Member No.: 251 Region Association: None |
QUOTE(Demick @ Nov 6 2004, 10:19 PM) Did you measure and set the crank endplay with the appropriate flywheel shims? Could be to little thickness in those shims causing the endplay to be near-zero, which could cause the tightness you are feeling. Demick Would it stand to reason that if this is the problem, removal of the flywheel and shims would release any binding? |
Demick |
Nov 7 2004, 11:29 AM
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#16
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Ernie made me do it! Group: Benefactors Posts: 2,312 Joined: 6-February 03 From: Pleasanton, CA Member No.: 257 |
QUOTE(swood @ Nov 6 2004, 10:52 PM) Too little or too much thickness? Not sure what you mean. Yeah, sorry - I meant too much thickness would cause binding. And yes, if you remove the flywheel, the binding would go away - if that is the problem. Demick |
Demick |
Nov 7 2004, 11:34 AM
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#17
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Ernie made me do it! Group: Benefactors Posts: 2,312 Joined: 6-February 03 From: Pleasanton, CA Member No.: 257 |
Also, what are you using for an oil pump and what are you using for a cam gear? Tolerances can be close between these and using the wrong combination can cause interference.
Demick |
wannateener |
Nov 7 2004, 11:48 AM
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#18
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The Bombdiggity Master Group: Members Posts: 115 Joined: 14-September 04 From: sierra nevada/cali Member No.: 2,759 |
i also suspect too thick shim washer between crank and flywheel
the most common mistake is to just reuse the same shims you must check your end play between the case and the flywheel i cant tell you how many times someone has brought me a type one after an owner rebuild with the statement, "just rebuilt it ,ran well for about 5 minutes and seized up." pull the engine , pull the flywheel , insert proper thickness washers ,instant fix. (IMG:style_emoticons/default/smilie_pokal.gif) in any case do not install this engine until you find the problem type fours without the plugs installed should turn without a lot of effort and NO binding good luck jt posting as my kid again |
swood |
Nov 7 2004, 11:52 AM
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#19
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Senior Member Group: Members Posts: 1,839 Joined: 6-February 03 From: Strong Beach Member No.: 251 Region Association: None |
QUOTE(Demick @ Nov 7 2004, 09:34 AM) Also, what are you using for an oil pump and what are you using for a cam gear? Tolerances can be close between these and using the wrong combination can cause interference. Demick T1 oil pump (clearanced) Shaedek.. Web cam 73 grind and new Web cam gear. |
Demick |
Nov 7 2004, 12:28 PM
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#20
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Ernie made me do it! Group: Benefactors Posts: 2,312 Joined: 6-February 03 From: Pleasanton, CA Member No.: 257 |
QUOTE(swood @ Nov 7 2004, 09:52 AM) T1 oil pump (clearanced) Shaedek.. Web cam 73 grind and new Web cam gear. Jake does say that clearance is very close when the T1 oil pump is used. Still - if this was the problem, I think you would have caught it earlier. I'm sure that you probably rotated the engine by hand after the oil pump was installed and before the P&C's were installed. Demick |
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