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Paul P Member

Joined: 15 Aug 2002 Posts: 2408 Location: Townsend, Mass. 81731.10 points
1971 Chevrolet Chevelle
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Posted: Thu Dec 02, 2010 11:52 pm Post subject: New 408 |
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Good news. The cam bearing journal in the block is not damaged. Good thing I was only going 10 mph when it spun. The engine is up at the shop in Hudson that Jeep and I use. I'll be going 4.160 over and putting some new pistons in it. Right now it looks like it will only cost me 575 to get the block cleaned,crank center line honed and all 8 holes honed out to 4.160 or what ever minimal amount cleans it up to save the block.
Not sure what pistions will cost but looks like 100 a hole basically.
Then on to the Dart 17s that will get finished up port wise as they were stalling at .600 lift at 308cfm should be more in them if that is fixed.
Only issue is my Pro-jection might have to go as it is not capable of feeding the new setup.
I'll post more later with pics as things come along. _________________ 2001 Focus 2.0 Zetec
stock cams, bolt-ons and tune
15.63@87 MPH 1/4mi
1971 - Chevelle 408 SBC N/A
6.86@102.5 MPH 1/8mi
10.78@122 MPH 1/4mi

Last edited by Paul P on Sun Apr 03, 2011 11:38 am; edited 3 times in total |
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af2 Member

Joined: 01 Sep 2003 Posts: 5558 Location: grassvalley, ca 71227.76 points
1933 Willys Coupe
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Posted: Fri Dec 03, 2010 12:46 am Post subject: Re: Spun cam bearing in 406 |
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Paul P wrote: | Good news. The cam bearing journal in the block is not damaged. |
OK
Why did it spin?
Sounds like not enough interference fit?
Or a cam that had too much journal size?
Just thinking.  |
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SMOKEmUP PostMaster

Joined: 30 May 2002 Posts: 3169
65097.54 points
1979 Chevrolet Camaro
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Posted: Fri Dec 03, 2010 12:49 am Post subject: |
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That's good news. Tell Chad from the machine shop I said hi. _________________ Stop running from your pain and embrace your pain. Your pain is going to be a part of your prize.
I challenge you to push yourself. |
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10sec.et Member

Joined: 29 Mar 2006 Posts: 3477 Location: Houston,Texas 346819.60 points
1969 Oldsmobile Cutlass
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Posted: Fri Dec 03, 2010 2:32 am Post subject: Re: Spun cam bearing in 406 |
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af2 wrote: | Paul P wrote: | Good news. The cam bearing journal in the block is not damaged. |
OK
Why did it spin?
Sounds like not enough interference fit?
Or a cam that had too much journal size?
Just thinking.  |
i had to polish the surface of the front cam bearing in my block to get the cam to turn smoothly. looked like the bearing just had a weird uneven surface. im sure if i hadnt cleaned it up it would have spun later on. fortunately mine was right out front. dont know how you would tell if you had a screwed up cam bearing further in. _________________
af2 wrote: | It seems we can look at our magical Balls and come up with a fix?
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clay Moderator

Joined: 24 Nov 2002 Posts: 3209 Location: South Carolina 318129.23 points
1972 Chevrolet Nova
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Posted: Fri Dec 03, 2010 11:21 am Post subject: |
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Good news. Sounds like some evilness in the making . I haven't heard of a cam bearing spinning before. This engine has been together for a while right? Things like this that happen on a new build are one thing, but when they happen on one that has been together a while, it puzzles me. Clay _________________ I have done so much with so little for so long, I can now do anything with nothing. |
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Paul P Member

Joined: 15 Aug 2002 Posts: 2408 Location: Townsend, Mass. 81731.10 points
1971 Chevrolet Chevelle
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Posted: Fri Dec 03, 2010 5:00 pm Post subject: Re: Spun cam bearing in 406 |
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af2 wrote: | Paul P wrote: | Good news. The cam bearing journal in the block is not damaged. |
OK
Why did it spin?
Sounds like not enough interference fit?
Or a cam that had too much journal size?
Just thinking.  |
I was told likely journal to tight but I believe there was a bit of not enough interference fit as well.
One of my theories is I just changed engine oil to Mobil 1 15w-50 full synthetic Racing formula. Not sure if the lack of ZDDP was the culprit. Kind of a back of my mind thing. Oil pressure was better and more stable than with other oils. It was slippery enough to save the block so I don't know what to think.
It is puzzling.  _________________ 2001 Focus 2.0 Zetec
stock cams, bolt-ons and tune
15.63@87 MPH 1/4mi
1971 - Chevelle 408 SBC N/A
6.86@102.5 MPH 1/8mi
10.78@122 MPH 1/4mi
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af2 Member

Joined: 01 Sep 2003 Posts: 5558 Location: grassvalley, ca 71227.76 points
1933 Willys Coupe
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Posted: Fri Dec 03, 2010 6:18 pm Post subject: Re: Spun cam bearing in 406 |
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Paul P wrote: | af2 wrote: |
OK
Why did it spin?
Sounds like not enough interference fit?
Or a cam that had too much journal size?
Just thinking.  |
One of my theories is I just changed engine oil to Mobil 1 15w-50 full synthetic Racing formula. Not sure if the lack of ZDDP was the culprit. Kind of a back of my mind thing. |
Paul that lack of ZDDP is the main reason I won't run synthetic in anything I own.
Everyone has made the arguments and will till we run electric.
My point is the ZDDP will give the 'cushion' if clearances are tight. As in no metal contact.
Kind of crazy how you just changed oil and cam hits the fan. |
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10sec.et Member

Joined: 29 Mar 2006 Posts: 3477 Location: Houston,Texas 346819.60 points
1969 Oldsmobile Cutlass
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Posted: Fri Dec 03, 2010 11:23 pm Post subject: |
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why run 50 wt oil ? i saw a 20° increase in oil temp just by going from 10w30 to 10w40. im seriously considering 5w30 for the new engine.
as far as ZDDP, i dont see where the newer oils would have an effect on cam bearings. lobes maybe if its flat tappet but if it has proper clearance i just dont see it taking out the bearings. i run Mobil 1 in my LT1 (as it has for most of its life). it has 179K on the clock and still runs strong. i do agree with Adam about tight clearances needing better lubrication but if it wasnt too tight to begin with...... _________________
af2 wrote: | It seems we can look at our magical Balls and come up with a fix?
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jeep_406 Member

Joined: 12 Sep 2002 Posts: 1661 Location: Tewksbury, Mass 01876 53123.48 points
1972 Chevrolet Nova
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Posted: Sun Dec 05, 2010 12:49 am Post subject: |
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Paul,
Ask Paul Rinaldi about oil. At Golen's, they now use Joe Gibbs oil when dynoing engines. They've found a lot less metal when they cut open the oil filters after break in. |
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Skunkworkx Member

Joined: 02 Sep 2007 Posts: 352 Location: Harford Co. Maryland 10318.16 points
1968 Chevrolet Camaro
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Posted: Sun Dec 05, 2010 9:41 pm Post subject: |
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Funny you bring up the oil change and spun bearing.
I changed to a synthetic blend...no sounds,knocks,squeals,nothing Changing cam a few weeks later and found metal (bronze looking) in lifter valley...thought it was from the valve guides. nope
Ended up pulling motor,found #1 and#2 mains gone,crank scored.
No more syn. oils for me  _________________ 68 Camaro LSx
AKA:RedЯum |
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Paul P Member

Joined: 15 Aug 2002 Posts: 2408 Location: Townsend, Mass. 81731.10 points
1971 Chevrolet Chevelle
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Posted: Thu Feb 24, 2011 6:57 pm Post subject: |
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Site is kind of quite these days what's up with that?
Update for ya.
I got the Dart 17 heads and Intake back from HRD. These guys do top notch work for many of the best out there including all the big names in Nascar and more. They out flow my old Dart Sportsmans at .400 lift and flow 310cfm and more from .500 lift up. I have another cam coming from Tim at Bullet Cams. These heads should put me in the mid 600's HP wise easily.
They did some of the best work I have seen no BS. Can't wait to see what this will do on the track.
Paul _________________ 2001 Focus 2.0 Zetec
stock cams, bolt-ons and tune
15.63@87 MPH 1/4mi
1971 - Chevelle 408 SBC N/A
6.86@102.5 MPH 1/8mi
10.78@122 MPH 1/4mi
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William Jones Member

Joined: 30 Jan 2006 Posts: 823 Location: Lake city, FL 28541.86 points
1971 Ford Mustang
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Posted: Fri Feb 25, 2011 1:20 am Post subject: |
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Thats great news Paul I hope she runs like a scalled dog when she done.
Bam _________________ Take the horse out off the barn and let her RUN BABY RUN!!!!!
92 LX 454ci Clevor 9.24@142.53 N/A
71 Mach1 454ci Clevor 10.16@134 N/A 3850lbs race weight "Lost in fire"
03 Cobra Bone stock 12.42
68 Falcon 363ci 10.55@126 N/A
95 GT 363ci 11.08@118 N/A |
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jeep_406 Member

Joined: 12 Sep 2002 Posts: 1661 Location: Tewksbury, Mass 01876 53123.48 points
1972 Chevrolet Nova
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Posted: Fri Feb 25, 2011 2:45 am Post subject: |
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Paul, Have you decided on what you're going to use for a piston? |
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Paul P Member

Joined: 15 Aug 2002 Posts: 2408 Location: Townsend, Mass. 81731.10 points
1971 Chevrolet Chevelle
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Posted: Fri Feb 25, 2011 4:00 pm Post subject: |
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Cam was first thing needed according to Paul Rinaldi. Piston will likely be a flat top from Diamond. Chambers are at 60cc's. I am lucky that the cam that I selected with Tim's help at Bullet cams with .690" lift is right for the 934 Pacaloy springs I bought for these heads. The springs are over $300. Should be impressive gains compared to the old setup. _________________ 2001 Focus 2.0 Zetec
stock cams, bolt-ons and tune
15.63@87 MPH 1/4mi
1971 - Chevelle 408 SBC N/A
6.86@102.5 MPH 1/8mi
10.78@122 MPH 1/4mi
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squeeezer Member

Joined: 02 Mar 2007 Posts: 2427 Location: new richmond WI 191524.76 points
1991 Chevrolet Camaro
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Posted: Fri Feb 25, 2011 6:50 pm Post subject: |
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whats that gonna run 12 o 1 static
what size cam you gonna run duration wise?
and what fuel do you run? _________________
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