*This message was transferred with a trial version of CommuniGate(tm) Pro*
-----Original Message-----
From: James Burrill <jburrill@dttus.com>
To: Military Vehicles List <mil-veh@uller.skylee.com>
Date: 24 January 2000 20:31
Subject: [MV] Chev 235 break-in question
> Just finally finished swaping a rebuilt '54 235 straight six motor for
> the 42' 216 straight six that threw a piston rod.
>
Oops, oily bit escaped to the daylight.
> The WWII manual says to keep the speed below 20 Mph for the first 200
> miles and below 30 mph for the next 300 miles, then a top speed of 35
> mph is ok.
>
This doesn't really describe the requirement for good break-in (run-in), what is
ideally needed is very light engine load initially, with modest revs and
steadily increasing the demand over several hundred miles. All very well saying
keep the speed below 20 MPH but uphill with a floored pedal will do it no good
at all and likely have it nip up. The first 100 miles are the most critical.
> I will probably die of old age before I finish 500 miles on the truck.
>
> What would a comparable engine run time be for break in, in leiu of
> actual milage. NOTE: the tranny and driveline are already broken in.
>
Varying engine loads and revs as the mileage increases are the way to go,
running the engine on a light load and fixed revs for hours is not ideal at all
and in some cases can achieve little.
> If I have the truck running for time, how often should I reve it up?
> or run it at a highr RPm using the throttle?
>
Largely a waste of time just leaving it running as you infer. It could be done
on a dyno though in a day or so.
> You get the picture of what I need to do.....
>
> Suggestions?
>
Drive it about gently to start with, certainly 1/4 throttle or less for the
first 100 miles and then allow it to rev a little more and use some more gas
pedal until you are giving it short periods of full go at 500 miles, afraid it
takes time, there are no shortcuts.
Richard
(Southampton UK)
This archive was generated by hypermail 2b29 : Mon Feb 21 2000 - 18:15:14 PST