VCCA Home Forums TECHNICAL - GENERAL Mechanical - Engine, Trans, etc 261

Gene, is it possible to use flat tappet lifters and flat cam or must one stick with the hydraulic?

All lifters and cams for this engine would be of the flat tappet type.....an non -flat would be a roller lifter.
Yes, you could put a solid lifter cam and lifters in the engine.
The other cam sold by Chevrolet was the solid lifter cam used in the 6 cyl Corvette, 261 trucks, and 1956-1958 235 trucks. But its lift, etc. was no better than the hyd cam you have. You could find some other brand but make sure it was NOT made in China, its properly hardened, installed as per instructions and has a gaurantee not to have lobe problems.

If it had hydraulic lifters, wouldn't it have had hollow pushrods and special rockers? Or is that a more recent thing?

The Hyd and solid lifter engines had the same push rods, rocker arms, etc.

Thanks Gene

No the hydraulic lifter rockers and the mechanical lifters all have the same pushrods. tubular pushrods were introduced on the small block V/8 engines and were introduced on the sixes after the 235 and 261 engines were discontinued. The new single stud rockers were the first stock Sixes with hollow pushrods that oiled the rockers.

Thank you Mack!

One more thing. I was told that I must use VR-1 Valvoline, cause of the zinc. Supposedly, the zinc was removed from alot of other oils. Have you heard this?

I don't think that is so, unless of course you are building this engine up for 100% full bore racing. Will you be running a very agressive cam and double strength valve springs and expect to have most of your trips at max RPM under heavy load of racing slicks? However if you feel better using $5 a Quart motor oil I am sure it won't harm the engine. Just remember that Chevrolet recommended using 20 Wt. oil up thru normal temps for most of the US and 30 Wt for areas of extreme temps back when the engine was original. I would use modern SAE 10W30, SAE 5W-30, SM, SL That is what Mr. Goodwrench oil for a modern Chevrolet is.

Well, It is my daily driver from spring till fall, and I take it on the hwy's. The cam is a #264 3/4 grind from Patrick's and the head was done by Clifford's. 1/16" over bore on the 235 HD Motor. It still won't be faster than a Volkswagon bug, but, I just don't feel like lunching another motor. It was not real pleasant pulling that 216. I want this to be the last time that motor has to come out. The 216 radiator should be okay, dont you think?

So flat tappet cams do not need appreciable ZDDP?

In general engines only need a zinc supplemented oil on initial break in. Most assembly lubes have what is needed. Once the parts are coated then additional zinc does little good.

There is still zinc in 10-30 etc SM oils. The amount of zinc has been reduced by about 20 percent, thats all. A special camshaft break-in additive should be used for cam break-in. This was recommended by Chevrolet as far back as 1958. GM sold EOS (engine oil supplement) for this purpose but it has been discintinued.
The racing oils have more zinc but because they are used for racing they lack other additives required for a passenger car engine. A 10-30 oil is still best for mormal service. If I were breaking in a new engine today I would used 5-30 and nothing heaiver than 10-30. Most racing oils like a #40 or #50 which is way too "thick" for the tight fitting parts in a fresh engine.

At one time you could buy hollow push rods for 207, 216, and 235 engines. They were stronger and will flex less and lighter for high RPM use. I have them in my 1934 and 1939.

Would the McGurk tubular pushrods from my 216 be OKAY?

Also, I've noticed on the 235's and 261's there aren't any front and back exhaust bolts, just the smooth studs. Is it a bad Idea to remove those so that one might put in bolts, I am intending to use my headers on it, and I thought it was probably so the stock exhaust can expand and contract without cracking, as I have seen many stock manifolds that are cracked.

Why would you want to remove the alignment studs and replace them with bolts? When you tet one of these ideas, maybe it would be a good idea to go out to the shop and work on something, less important. I for instance often get out the Brasso and get to polishing up some lenses, parking lamp, instrument panels, etc.,etc. or hunt up a manifold or bell housing to detail and paint. I also have my mechanical whatchmacallit that I am always modifying. Last thing I do is look over at the big lever on the whatchamacallit and wonder if.....I should pull it or not. I named it lever "B" and once I understand it's function I am OK! :vcca:

Just kidding, I know that when we are getting more and more anxious we find something else to wonder about!

The push rods for a 235-261 are a different length.
The end studs were only guide pins on that later manifolds. For headers I would remove the guides and install studs.
The 1947 radiator should be sufficient if its in good condition and cooled the 216 OK.

Gene, if you ever listen to Oconomowoc Radio on Saturday Morning, They have an "on air rummage sale" Last fall I found a NOS Radiator for $50. I have been saving it for this moment.

Next, I have a 235 starter off of that 50-51 235. Is that okay to use on the flywheel from the 55' 235, and if so, was that still 6 volts?

Mack, if it weren't for those ideas, where would we be?! For instance, I own a diner, I serve 500 eggs a week. Now, can you imagine, the first dude who saw one fall out of a chickens Rear, and said "Hmm, I should eat that" OR, when you learned about the birds and bees, and you thought..."I AM SUPPOSED TO DO WHAT?!?!"

The starter will fit , etc but MAY be a little low on power. You can see ow it turns over the engine when hot. The best starter is the one from a 1954 Power Glide.

A friend/VCCA member from Lodi has a 1947 Fleetline 4 door, 216 but with dual carbs and exhaust. HE had an over heating problem for years. Would heat up if he drove it at 60 MPH. Had the radiator recored etc. and the problem continued. Then he found a NOS core and has no more heating problem. There is no substitute for a NOS radiator.

Is you resturant on HY 19 ?

Yep, Right on the corner of HWY 89&19 Got a great Napa Right next door. Lots of Bartering! If you ever feel like taking a nice cruise over here I'll buy your Breakfast for all your help. Same for you MrMack! Just avoid Tuesday Mornings at 7am. I host the local Model A restorers club. And let me tell you, they are a different breed. They gave me hell for putting on steel belted radials. But, when I ask them why they all have Delco Alternators on their Model A's they change the subject! They gave the business when I put Mallory Dual Distributer on. I asked why they all have batteries invented by GM Delco (Maintainence Free) They told me Henry had the Idea first!

Also Gene,

I am supposed to say hi to you from James "Skip" Archie here from town. He's got an Original '41 with the paper still on the inside of the doors. He's been swearing for the last 10 years he will start it... Never happens

Is that the black Fleetline 4 door? I haven't seen that car in well over twenty years but often think about it. Was as nice of an original car that you could find.

Thats the one. His wife bought it for him back in the 1960's, for a anniversary present. It is everybit as great now, as it was then. He's also got a '28 Buick 8. And a later Buick. He was a Chevrolet accesories salesman for awhile.