Kent Break In

[Jim Garry]

A friend and I both have newly refreshed Kent engines that have zero time on them, including no dyno time. Both professionally rebuilt.

These engines will be used in autocross cars which means no opportunity to run easy on a track for 15 minutes.

So that means just running them at 2000 rpm or so, getting the rear wheels off the ground and putting it into 3rd gear for a little load for a little while. Then rev it up and down for a bit.

Will this be sufficient to break them in or are there recommendations to do something more?


Thanks!

[TimH]

What builder doesn't put his motors on the dyno before shipping?

[DanW]

What builder doesn't put his motors on the dyno before shipping?

Only if you ask him to.

[Lynn]

Break in with an oil with a high zinc content. Do not use synthetic oil. Change oil after break in.

[Jim Garry]

Yup, already added Valvoline VR1 and got oil pressure. Just trying to pick the run time and method. Maybe ovethinking.

[Lynn]

Jim, my engine builder for the SoloVee, which is approximately the same hp and torque as the Kent, advised 15 minutes at 2000 to 2500 rpm, followed by a brief period at idle, then some slowly increasing revving. Not to read line. Say about 4000 rpm. Then change oil while hot.

[DanW]

The reason for break-in is to seat the rings in the bores. Take the car to an industrial park or large parking lot on a Sunday morning and drive it at 2000-3000 rpm up and down the roads in second or third gear. Accelerate up to speed, then slow, then back up to speed.

Repeat for about 30 minutes or until the cops show up.

[Rondo]

Jim - PM me your email. I work with a builder who has me break in my engines. He has very detailed written process and it has worked very well for me over the last 10 years. I will scan and send to you

[t walgamuth]

When I had the hot K20 redone in my Lotus 7 replica d mod I took it out in the back lot area at Grissom and ran it up and backed off about 20 times, then put it in line to run at racing speed. I believe I may have taken it easy for a few runs then hammered it. No worries! Break in oil for a while then right onto the full synthetic racing oil.

With the metals we have now I suspect it is not much of a worry really.

[Jim Garry]

When I had the hot K20 redone in my Lotus 7 replica d mod I took it out in the back lot area at Grissom ...

But I have zero access to such a place. I know of no clubs locally that will let me drive around on their site for awhile. I envy you.

As for the earlier suggestion to take it to an empty business park or unfinished development ... well, any New York police department seeing that will arrest me and will confiscate and sell the car.

[billtebbutt]

Jim,

Are there any small, local drag strips with a "run whatcha brung" evening, like on a Monday nite? Alternatively, do you have a buddy who runs a small aircraft out of a regional/hobby airport a couple hours outside of the city, that could pull a few favours for you?

cheers,
BT

[t walgamuth]

But I have zero access to such a place. I know of no clubs locally that will let me drive around on their site for awhile. I envy you.

As for the earlier suggestion to take it to an empty business park or unfinished development ... well, any New York police department seeing that will arrest me and will confiscate and sell the car.

Where does your local club run? We run at Grissom. The back lot is where we park our rigs. There is usually some extra space. Or call your local police. They might be able to recommend a local park in off season.

I did this in West Virginia when I bought my 85 Reynard. No problemo. Just talk nicely and keep talking until he says ok or butts off.

[John Robinson II]

Regardless of how you beak it in, make sure any oil you run has a high zinc content. If you are running the generic off the shelf synthetics, the zinc content is not high enough. I had major wear issues with Mobil 1. Switched to brad penn semi synthetic but now run amsoil v-rod. FWIW, Butler now recommends brad penn.

John

[Offcamber1]

The last time I broke in the motor on my Royale, I took it to a friend's new car dealership on a sunday. we blocked off the entrance so nobody could surprise us, then drove around the building in 1st and 2nd gear for a half hour.

[Roux]

Jim,

years ago I found a small asphalt oval in PA that rented for cheap, cannot recall the details or where it was. Also how about large gokart tracks. You rent for one hour only. the Autorcross track at limerock can be run continuously as they do on their rather pricey autocross events. I wonder if you could ask the guys there that run the events to let you do the break in prior to them running an autocross, They are nice guys and will understand what you are trying to do. in most cases I present you need to shell out a few hundred bucks, but knowing that you did it right will be worth it. About the same you would have had to pay for dyno time. I agree with you on the 'no way to do it on the street' I just cannot imagine getting 30 minutes in without a visit of some sort. .

But I have zero access to such a place. I know of no clubs locally that will let me drive around on their site for awhile. I envy you.

As for the earlier suggestion to take it to an empty business park or unfinished development ... well, any New York police department seeing that will arrest me and will confiscate and sell the car.

[stonebridge20]

Jim, just go break it in on a chassis dyno.

[Jim Garry]

Thanks guys.

[mark elder]

Agree with the chassis dyno and yes, proper running in oil.

Bedding rings is about increasing cylinder pressure enough to force the rings outwards towards the bore. That way they rub with enough force to actually bed in (vs gently running the engine at say 2500rpm and minimal load; this is a sure way to glaze the bore and never bed them).

So.... on the chassis dyno (or carpark etc), its, say, 3rd or 4th gear and wide open throttle from, say, 2500 until 4500 then foot off throttle and coast back to 2500 then repeat. Fourth gear sort of puts more load on and it is slower to get the 4500.

Do this for 10 minutes. Stop. Let it cool. Repeat x 3. Last session goes to 5000 then the last run is 5500.

Running in is both for ring seal and the heat cycles (need 3). If I could, I would do the first season in the morning, then the second at the end of the day and the third the next day. Some dyno guys do the same. You can measure crankcase pressure (= ring blow by) and keep cycling til the pressure plateau's).

When you are done, do a leak down test (should be 5% or less on all 4). Then go and race.