Quote:
Originally Posted by 69halfton
i just had an engine built (383 stroker) the man who built it has been in buissness for years, he builds many engines for the CASCAR racing series, so i would think he knows his stuff. He told me NO SYNTHETICS, also, the 20 mins at 2000 rpm is a bit out dated,
he said to just drive it, and dont baby it either. he says dont pull out of the drive and go WOT, but you can give a little push now and then.
Drive it like this for a month or so, and then change oil & filter, and your set to go to the dragstrip.
the reason that you can get away with this now, is that everything is machined to be perfect fit, with the advancment of computer technology etc.
the only thing your ACTUALLY breaking in on your motor would be the piston rings.
an old trick that many people used to do when they had new rings was..
take your truck out, and accelerate pretty good up to 50 mph, then back right out of the throttle and let it fall down to 15 mph, then repeat about 5 times.
after that feel free to hammer on your engine all you want.
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Man, I have to disagree with almost all of this. For the cam break-in, this is against the manufacturer's recommendation. IMHO, I'd do it the way the cam company says. I've put the CompCams instructions at the bottom.
Drive it for a month and change the oil and filter? No, absolutely not. There is all kinds of gunk from assembly lube, etc. that is going to hit that filter. Cut one apart after break-in...it'll be a little scary, but you'll see just how much garbage there is. Oil and filter changes are your friend -
the way you treat your engine in the first 20 hours of operation will determine how much power it makes and how long it lasts.
In terms of computer tolerances...we've been holding tolerances in these things to .0005 for a long time. It's become CHEAPER and FASTER to do this - but this hasn't really changed at all.
New moly rings don't require much to seat - they generally seat in the first few minutes. The old driving break-in process still applies IMHO; avoid full-throttle, vary between 30% and 70% throttle, etc. You should drive within these ranges as much as possible for the first 300 miles or so, and then the engine is fully broken in.
I'm not saying your guy is wrong - but he builds engines for a very different purpose than a street engine and with very different parts.
From CompCams:
Camshaft Break-in Procedure
Important: On hydraulic and mechanical (solid) flat tappet cams that require dual valve springs, the inner spring must be removed during break-in. This allows the lifters to establish rotation and develop a good wear pattern. As soon as the engine fires, bring the RPM up to 2000 to 2500 during the first 30 minutes of operation. Slower engine speeds will not supply the camshaft with an adequate amount of oil for the break-in period. The engine RPM may be varied periodically between 2000 to 2500 to direct oil splash different areas of the camshaft. After the 30 minute break-in period, change the oil and filter again to be sure all contaminants and break-in lube are remove from the engine. The inner valve springs can now be replaced.