How long do I have to wait until I can peel out?
#943232
03/05/11 03:15 AM
03/05/11 03:15 AM
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Joined: Feb 2010
Posts: 18,493 Granite Bay CA
Kern Dog
OP
Striving for excellence
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OP
Striving for excellence
Joined: Feb 2010
Posts: 18,493
Granite Bay CA
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Ahhh... the age old question. When we hear about a "Break in" procedure for a new or rebuilt engine, what is it that we are doing? I have read about how you should avoid full throttle starts for the first 500 miles and all that, but.... I doubt that all the new cars built until the advent of roller cams had a cam and lifter break in session as we all do with the classic motors we rebuild now, yet how often were cam failures back in the day? I have read that during the first 500 miles, the rings are seating, the cam and lifters are forming patterns to each other and who knows what else. I have also heard of guys that fire up the motor, break in the cam, then haul ass and never look back. Maybe those guys had to pull their motors at 20,000 miles to slap in another set of rings though! I'm going to install the 440/493 this weekend and I hope to have it running early next week. I'll be driving to LA next month for the Spring Fling, and it will be the longest that car has been from home since long before I bought it in 2000. The 800 mile round trip will surely satisfy the outline of an engine break in period. I was just curious as to how long other members wait until they let the hammer down....
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Re: How long do I have to wait until I can peel out?
[Re: Kern Dog]
#943235
03/05/11 04:51 AM
03/05/11 04:51 AM
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Joined: Mar 2007
Posts: 3,287 West Coast, USA
jbc426
master
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master
Joined: Mar 2007
Posts: 3,287
West Coast, USA
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Do you know the clearance on your rods and mains? The main thing I try to do is to make sure the engine and oil are up to temperature before I stretch it's legs, don't lug it below 2000 rpm and make sure the timing and A/F ratio is set-up right. After making sure all that's good, get out there and put together some wide open throttle time.
1970 Plymouth 'Cuda #'s 440-6(block in storage)currently 493" 6 pack, Shaker, 5 speed Passon, 4.10's 1968 Plymouth Barracuda Convertible 408 Magnum EFI with 4 speed automatic overdrive, 3800 stall lock-up converter and 4.30's (closest thing to an automatic 5 speed going)
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Re: How long do I have to wait until I can peel out?
[Re: jbc426]
#943237
03/05/11 06:04 AM
03/05/11 06:04 AM
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Joined: Feb 2010
Posts: 18,493 Granite Bay CA
Kern Dog
OP
Striving for excellence
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OP
Striving for excellence
Joined: Feb 2010
Posts: 18,493
Granite Bay CA
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I set the crank wednesday and the rods and pistons today. I checked all journals with plastigage. Mains: 1 .0015 2 .0015 3 .00175 4 .002 5 .0025 I thought that it was wierd that the clearances got larger toward the rear. No problem though. Its all within the range. All the rod journals are between .0015 and .002. The 7/16 bolts on these Manley rods call for 85 lbs of torque! Also, to recap, this motor was torn down to address an oil consumption problem. The cylinders were honed, Fresh standard rod and main bearings put in, new rings file fitted to each cylinder. I'm reusing the '509 cam and lifters since they are in great condition and I kept the lifters in order. That article in the link has me curious... I do recall an engine builder way back in the early 90s saying to avoid steady speed driving (like as in CRUISE control) and no full throttle runs. Wow... that doesnt leave much, does it? Cant drive slow. Cant drive fast. What CAN I do?
Last edited by Frankenduster; 03/05/11 06:08 AM.
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Re: How long do I have to wait until I can peel out?
[Re: Challenger 1]
#943239
03/05/11 10:19 AM
03/05/11 10:19 AM
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Joined: May 2003
Posts: 15,487 Florida
scratchnfotraction
I Live Here
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I Live Here
Joined: May 2003
Posts: 15,487
Florida
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I am a 'break in the cam' give it he77 kinda guy rather have it come aprts close to home than 400 miles away if it has no trouble its good to go in my book my last one lasted 10 yrs and it come out the yard on the cam break in at 4800 rpms after a 5 min idle break in time good luck oh! I would use a lot of zinc additive with some good oil then roll
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Re: How long do I have to wait until I can peel out?
[Re: scratchnfotraction]
#943240
03/05/11 11:52 AM
03/05/11 11:52 AM
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Joined: Jan 2008
Posts: 3,886 Lost and Spaced
bboogieart
master
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master
Joined: Jan 2008
Posts: 3,886
Lost and Spaced
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The instructions we were given by the dealership were just drive it normal and DO NOT use cruise control for the first 500 miles. The reason for this is to vary the rpm. The rings will seat better if you do not drive the first 800 miles at the same speed. Running the same rpm will develope ring seal leaks at all rpm's but the one the rings broke in at. Vary the rpm and the rings will seal at all rpm's. So break in the cam and go but vary your first 500 miles or so from say 65 to 45 to 65. Get off the free way and do some cruising then back up to 65 down to 45 and so on. Might be what caused the oil consumption in the first place. a little simple for an explaination but you get the idea, right?
I have mechanical Aptitude. I can screw up anything.
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Re: How long do I have to wait until I can peel out?
[Re: Kern Dog]
#943242
03/05/11 04:38 PM
03/05/11 04:38 PM
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Joined: Jan 2003
Posts: 2,648 USA
max
super gas
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super gas
Joined: Jan 2003
Posts: 2,648
USA
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Quote:
I set the crank wednesday and the rods and pistons today. I checked all journals with plastigage. Mains: 1 .0015 2 .0015 3 .00175 4 .002 5 .0025 I thought that it was wierd that the clearances got larger toward the rear. No problem though.
From what I have been told here by my local builders is to step up the bearing clearance towards the rear to reduce the oil pressure at the rear main seal to keep it from leaking.
Coarse I always run the same bearing clearances all the way through and have never had any issues.
As far as break in time, a bearing is a bearing and it's either installed right or wrong so after about 5 minutes it time to cut it loose besides what do the cam manufactures suggest for cam break in.
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Re: How long do I have to wait until I can peel out?
[Re: Challenger 1]
#943243
03/06/11 11:15 PM
03/06/11 11:15 PM
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Joined: Mar 2003
Posts: 5,193 NEW JERSEY
AARCONV
master
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master
Joined: Mar 2003
Posts: 5,193
NEW JERSEY
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Quote:
After it runs for about 5 minutes, it's ready.
i agree, built a grand national turbo motor and ran it right in the streets hard with 18 pounds of boost...if it's gonna go it will go..have faith in your build...I did....
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Re: How long do I have to wait until I can peel out?
[Re: max]
#943246
03/13/11 04:11 AM
03/13/11 04:11 AM
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Joined: Feb 2007
Posts: 1,025 Las Vegas, NV
dodgeboy11
super stock
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super stock
Joined: Feb 2007
Posts: 1,025
Las Vegas, NV
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Quote:
From what I have been told here by my local builders is to step up the bearing clearance towards the rear to reduce the oil pressure at the rear main seal to keep it from leaking.
More oil clearance will mean more oil spray so that blows that theory out of the water. The clearances are a little tight for a motor with that large of main journals. Definitely make sure the oil is warm before you start thrashing on it. If the cam is already broke in then the only thing that needs to seat is the rings. The only way they do that is to put a load on them. Which means high gear (keeping local speed limits in mind of course), full throttle and proper timing and fuel mix. First 408 I built for my truck, I broke in the cam, took it a little easy, varying speed and throttle application. Took 200 miles for it to quit burning oil. When the crank broke I threw together a 360 magnum, hyd roller cam, so no break in. Soon as it had warm oil I was running it like it'd been in there for years. It never burned a drop of oil. 1/16 rings on the 408 and 5/64 on the 360 may have had something to do with it, but I dunno. I will say though, I ran a fairly smooth finish on the cylinders and the 360 did start to huff a little oil after 30k miles, but only on decel/high vacuum. Under load, nothing. Thought it was guides, it wasn't. Rings were half worn out. I think they needed a bit coarser finish to keep them oiled.
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Re: How long do I have to wait until I can peel out?
[Re: Kern Dog]
#943251
03/13/11 04:33 PM
03/13/11 04:33 PM
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Joined: Jan 2003
Posts: 4,757 Moved to N.E. Tennessee
GomangoCuda
master
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master
Joined: Jan 2003
Posts: 4,757
Moved to N.E. Tennessee
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1. Break in the cam 2. check for fluid leaks and levels 3. Check and adjust timing, idle mixture etc. 4. drive it like you stole it.
In theory, there is no difference between theory and practice. In practice, there is.
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