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> Motor is tight when turning by hand
swood
post Nov 6 2004, 10:14 PM
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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.
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swood
post Nov 7 2004, 06:31 PM
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Not to beat a dead horse, but if the case, crank and rods are the same as what was used before, the flywheel resurfaced and the same 3 shims and only the cam, cam gear, oil pump, cam followers and pistons/rings are new, would the crank end play even change?

(IMG:style_emoticons/default/wacko.gif)
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Matt Romanowski
post Nov 7 2004, 06:53 PM
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A couple of things to check:

First - Crank Endplay as pointed out. Not only will too tight cause problems, but too loose can also.

Second - If the problem is only with the valve train hooked up, investigate there.

Third - Do you have sufficient deck height? Are the valves hitting the pistons?

Fourth - Is their coil bind in any of the valve springs? Watch this with dual springs.

Fifth - Is there a rocker issue? Do they rotate freely?

Sixth - Were the heads completely prepped? Enough Assembly lube?

Hope this helps.

Matt
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newdeal2
post Nov 7 2004, 10:35 PM
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I don't think this is anything serious [imho]. I had a change once the pistons were loaded and the heads/rockers assembled but only at certain points which leads me to beleive it is just the riesistance of the pistons. I also notice a "puffing" sound with this and I am pretty sure it's the pistons forcing air.

Jake's video only says the engine should turn easily prior to installing the pistons. This is to be sure the bearings are set correctly. Any resistance and it's time to go back in and check. I know this because it happened to me. I almost killed one of the bearings!

Perhaps you should crank the engine with the coil wire removed and check your compression before you do the start up. I plan on attaching a pressure gauge in the engine bay on start up day.
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redshift
post Nov 7 2004, 10:37 PM
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QUOTE(swood @ Nov 7 2004, 03:01 AM)
WOuld you like to buy some meat over the phone?

I hope this doesn't get deleted..



No thanks buddy, not gay.
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Jake Raby
post Nov 8 2004, 12:13 AM
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If the engine doesn't spin freely- It will die a painful, short lived death!

When did you note the engine starting to get difficult to turn?? What is the end play set to??

Let me help you through this because otherwise you can become a statistic very quickly..

did you set the skirt clearance on those cylinders and pistons? Where did they come from? All are NOT created equal and some are screwed up right out of the box!
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newdeal2
post Nov 8 2004, 12:35 AM
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Now this is getting scary (IMG:style_emoticons/default/ohmy.gif)

Mine turns freely with what feels like a suction resitance at certain points. I had flywheel endplay set at the Porsche shop when we did the case and crank. I installed the flywheel before the pistons and it was very smooth.

I assumed once the pistons, cylinders and heads were installed there would be some resitance.
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newdeal2
post Nov 8 2004, 12:37 AM
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BTW Jake...welcome back. I hope you had a great week (IMG:style_emoticons/default/cool.gif)
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Jake Raby
post Nov 8 2004, 01:42 AM
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It was a good trip.... Relaxing and now I'm ready to kick some serious ass and get moved into the new shop!

You will encounter some resistance, but it will not be drastic.

It is imperative when assembling an engine that between assemblies being installed to rotate the engine and get a good "feel" for what the assembly did to the way the engine turns.

Doing things this way ensures that drastic differences are caught and the finger can be pointed to the problematic area easily.

Yet again I ask about piston/skirt clearance and what pistons and cylinders you used....

If you have to be scared- do it, you only have one chance!
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swood
post Nov 8 2004, 09:31 AM
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QUOTE(Jake Raby @ Nov 7 2004, 11:42 PM)

Yet again I ask about piston/skirt clearance and what pistons and cylinders you used....

If you have to be scared- do it, you only have one chance!

Hey Jake, Welcome back. I used the stock jugs overbored to 96mm with KB pistons, hastings rings. I checked the skirt clearance and it was within tolerance. I don't have my notes with me now.


As I recall the pistons went into the jugs with no resistance. I just think that it's the rings dragging in the cylinder. ??
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Mark Henry
post Nov 8 2004, 10:02 AM
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Try it without the rockers on.
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swood
post Nov 8 2004, 10:05 AM
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It was without the rockers on. THose move smoothly by the way.
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Mark Henry
post Nov 8 2004, 10:17 AM
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Rings have a fair bit of drag, but it shouldn't tear your hands up. Time to tear it down and find out what's up.

Spin it as you take each part off till it spins free again.
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Jake Raby
post Nov 8 2004, 10:38 AM
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What tolerance did you use??

As soon as you go to the Hypereuctectic pistons the stock tolerances are thrown away due to a different expansion rate.

If those pistons are too tight they will smoke skirts in 10 minutes... Been there, done that.

Who bored the cylinders for you?
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swood
post Nov 8 2004, 01:38 PM
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They stock jugs were machined at European motorworks in Hawthorne.
KBs came from him to and were machined/balanced.

What should the clearance be on this set up?
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newdeal2
post Nov 8 2004, 08:12 PM
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I just finished pulling my rockers, checking the studs. and re installing them with new nuts to the proper 10 ft lbs.

When the rocker assemblies were off I checked the rotation and it was a little easier to turn [at the fan]. I think all is well. I am using hevy duty springs and they are most likely tightening things a bit.
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swood
post Nov 8 2004, 09:04 PM
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The skirt clearance was .002". I believe this is what it should be.

(IMG:style_emoticons/default/headbang.gif)
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Jake Raby
post Nov 8 2004, 09:49 PM
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Measured where on the pistons?? The KB pistons are measured differently than all others due to their skirt design..

I have seen many sets of cylinders too tight from European.. Those are not rebored German/ OEM cylinders- They are from a third world country...they are cast as 96s
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swood
post Nov 8 2004, 09:56 PM
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I think it was 1/2" or so up from the bottom of the loaded piston. Again, these are my overbored stock cylinders.
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Jake Raby
post Nov 8 2004, 11:42 PM
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Thats the wrong place to meadsure a KB!

The largest part of that piston is at the very bottom of the skirt. I found this out after 3 engines set at .002 1/2" up on the skirt smoked on the dyno.....

The pistons vary by batch...

So Euro Motorworks bored yours for you=- I see..
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swood
post Nov 9 2004, 08:19 AM
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So pray tell, where do you measure the skirt clearance on KB's??
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