Update on 216 to 261 engine switch

[Phil Waterman]

Hi All

Well I now have two completely rebuilt engines to go into my 3 Ton CMPs.

I've got the 235 up and running on the test stand see http://www.canadianmilitarypattern.c...ineTesting.htm bottom of the page for some photos and of course video of the new engine running. Still breaking, I mean running the 235 engine in couple of minor little things to fix like one noisy exhaust valve rotator.

One point of interest from running on test stand the T that connects the oil filter line and oil pressure line to the block broke the other day, so much for reusing 50 year old brass parts, fortunately I was standing at the control panel and saw this straight black line appear between the side of the block and the wall about 10 feet away. In the short time to realize what was happening it pumped 2 quarts out of the engine.

[Mike Timoshyk]

I just have to comment on the quality of websites offered by patrons of this website.

I visited in succession Phil Waterman's, Keith Web's and Hanno Spolestra's sites. All I can say is Bravo Zulu...

I am sure it has been mentioned before but, I just wanted to pass on my appreciation.

Cheers

Mike Timoshyk in Sunny Windsor Ontario...still cold, but sunny.

[Phil Waterman]

Hi All

Been working on the 261 engine which has the large full flow oil filter, while the 235 is running on the test stand to warm the shop.

In the picture at the top of this tread you can see the original full flow oil filter unit as used on the later 261 chevy truck engine. As I'm preparing the engine to start running it in I was working on the oil filter unit, comparing the original with the replacement spin-on type filter unit I plan to use. Couple of things I noticed one the original has a bypass valve if the the filter becomes plugged. It would seem a good idea as the new spin-on filter unit doesn't have this feature. So figured I'd find out at what point does the bypass open and discovered that basically always flowing oil and never really closing completely. With this in mind I guess the spin-on with no bypass is a more positive way of filtering the oil. It also means that if any of you are going to reused the original 261 filter units be sure to clean and check the filter bypass.

As to the 235 on the test stand this particular engine has the hydraulic valve lifters and valve rotators on the exhaust valves. While the engine sounds pretty good and getting better all the time, when you let the engine sit for a couple of days and the lifters all have a chance to leak-down all the way it sounds like a cement mixer full of rocks when you first start it until the oil pressure comes back up.

[Bob Carriere]

Hi Phil

That can't be right....... lifters should not leak down that easy or that fast..... unless the oil pressrue is tooo slow building up on start up.

My experience with Chev 6 goes back to the fifties.... all on 235 in cars with hydraulic lifters..... and even after parking the 58 chev for the Winter.... it never made a racket when staretd in the Spring... it might some a little from the oil in the cylinders but never noisy....... you might hear a clacking of valves for a few seconds.......but never more than that.....

Are you sure you didn't rebuild a diesel......????

Barry "Cherchez la femme" might have more practical experience with them...

Must be a lot of others running 235 with long shut down......

BooB

[Phil Waterman]

Hi Bob

Well maybe cement mixer is a little harsh, maybe a sewing machine, but with the engine sitting out in the open with no fan it sounds loud (fan is electric on the test stand right now). Just after letting the engine sit for 3 or 4 days the first time I started the engine the top end sounded like a 216 with really loose valves adjusters. Of course once the engine built oil pressure (you right a couple of seconds) the noise went away.

The leak down may have been helped by the fact that I'd left the block heater turned on so the engine sat over the weekend at 100 F which would have kept the oil thin. I'll repeat the experiment and see if it happens again.

The oil pressure cold or hot is holding very steady at just about 40 psi regardless of engine speed. With the engine run in a little now I can let it idle down to under 400 rpm with no problem, still limiting top rpm to 1500 and not for any length of time. When I'm running the engine I keep changing the rpm up and down every minute or so.

Cheers Phil