Dumb question #74

[Guest]

About to crank engine (in about a week or less) with new cam and followers with rebuilt head. Richard Good says to run at 2000-2500 rpm for twenty minutes then shut down and change oil and filter. I have always run Castrol 20/50 oil in my engine with good results. Is there any special oil that I should use for this breakin or just stick with the old standard?

An aside, I changed my thrust washers about 3 months ago and to my glee found they were still within perfect tolerance. I had bought every size imaginable, not knowing what to expect. Found that the stock size (the smallest) would fit, perhaps indicating no unusual wear on any moving parts, save the washers, had taken place. The thrust washers, being a sacrificial part, had done their job. Glad I had caught them when I did.

Bill

 

[Bugeye58]

Bill, the Castrol will work fine. Remember to vary your RPM within the 2000-2500 range, and don't let it idle.
Jeff

 

[Adrio]

One thing I did before first starting the rebuilt TR4A engine that I recomend highly is to run the oil pump for a few minutes without the engine running. I did this by removing the dizzy (all the way down to the oil pump). I then made an aluminium rod with the end the same shape as the bottom of the dizzy shaft. I put this in the hole so that it engaged the oil pump and then coupled it to a 1/2 inch drill and drove the pump until I had full oil pressure and let that run a bit to get the oil all through the engine.

After that I put the dizzy back in right away, set the timing staticaly and it fired up right away with oil pressure instantly. After that it was standard run in proceedures.

 

[Guest]

Good advice, Adrio. And correct me if I am wrong, I think one needs to run the oil pump counterclockwise for this to work, eh?

Bill

 

[Bugeye58]

Counterclockwise is correct, Bill. Make sure you have a good grip on the drill, as when the pressure starts to come up, there is a fair amount of torque on it.
Jeff

 

[vettedog72]

GREAT SCOTT! In Back to the Future, Doc needed 1.21 jigawatts , no more, no less!

Why does Doc need 2000 to 2500 RPM for a precise time? And then an oil change.

Bill, I would do exactlly as advised; but, without any belief in this VOODOO, it seems awful dumb. Still, I would do it anyway. /ubbthreads/images/graemlins/smile.gif

 

[Bugeye58]

Vette, the variable 2000-2500 RPM is for proper camshaft break in. It insures that there is a good flow of oil to everything, and that the lifters rotate properly in their bores for the initial run in. Proper oil flow is the reason for not letting it idle. The oil change is to get rid of any gunk that may be the result of the break in.
No voodoo involved, just proper procedures.
Jeff

 

[sammyb]

Don't forget to buy some Advil. Holding your foot on the accelerator for 20 minutes holding 2000-2500 might give you a cramp the size of Texas...

...but it's required voodoo.

(What's the line: I like the voodoo that you do ???)

 

[vettedog72]

Bill:
I saw the artical below and wondered if your new cam was close to where it should be without timeing adjustments?

From: pumaracing@aol.com (PumaRacing)
Subject: Re: Checking valve timing.
Date: 15 Jan 1999
Newsgroups: uk.rec.cars.maintenance

To check the cam timing you need to put a dial guage on the inlet valve on no 1
cylinder and a degree wheel on the crank pulley. Rotate the engine until the
valve is at full lift and read off the number of degrees after TDC on the
degree wheel. It can be hard to tell exactly where full lift is so do this:

Rotate engine to 1 thou before the full lift position. Read the degree wheel.
Rotate past full lift and back to 1 thou less - read the wheel again. True
full position is midway between the two readings. Check the manufacturer's
recommended full lift setting and correct with offset dowels or an adjustable
cam pulley if more than 2 or 3 degrees out. Easier to describe than do until
you have had a bit of practice at setting up engines.

Don't be surprised if the cam you bought is a long way out - many of them are
badly ground and not properly referenced to the woodruff keyway to ensure they
install at the correct timing on the standard sprockets. Probably just a good
ruse to get people to buy an adjustable sprocket too.

I have all my own cams properly ground so that they time in correctly on the
standard sprockets in the same way as the OE cams do. Maybe thats why I don't
make any darn money in this line of work /ubbthreads/images/graemlins/smile.gif


Dave Baker at Puma Race Engines (London - England) - specialist flow
development and engine work.