The Stovebolt Site Forums The Shop Area Engine Shop 261 Rebuild

I am currently rebuilding my 1956 Chevrolet 261 with an 850 head that came out of my 6100 2 Ton and I am looking for suggestions on what you did on your engine rebuild that you liked or didn't like. Right now everything is fully dissembled and I'm just waiting for the machine shop to tell me to deliver all the parts. Everything on it now appears to be stock and it does not appear that is has ever been taken apart to this level. The internals aren't too bad and all of the bearing oil clearances actually measured within spec for used components according to the shop manual (obviously they are all getting replaced). The only think that was obviously broken was one of the piston rings on piston number 4.

Are there specific things I should have the machine shop do besides the standard items? I am going to have the machine shop drill and port it for full bypass oil filtration but other than that I'm open to suggestions.

Are there any upgrades or modifications I should be looking at doing? I plan on keeping it pretty much stock but I have thought about putting on headers and a dual carb set up. What is your opinion on that set up?

What are some little specific things I should watch out for when reassembling the motor? I have the shop manual so it should be pretty straight forward but do you have any tricks or tips that apply to this specific motor?

What are your favorite gasket sets? Head gasket, Rear Main gasket, Oil Pan Gasket.

What parts of the motor would you suggest upgrading? HEI system, alternator, fuel pump, etc.

Are new cam shafts available or should I send mine out to be reground?

I know it's a lot of questions but this is my first engine rebuild that is bigger than a lawn mower.

Thanks

Headers and dual carbs are a waste of time and money. You'll end up with worse performance with dual carbs than with the factory setup.

I'm sure HRL will be along to tell you about a modification to make your rear main seal leak proof forever.

I like breaker point ignition and use them on all my cars with no problems on actual daily drivers. If you must use HEI, read the threads concerning that on this forum.

Here is a company that will convert your original dizzy to HEI using GM components.

Converts your original points style distributor to GM HEI system

DAVE's small-body HEIs
24 Buffalo Lane
Yerington, Nevada, 89447
775- 722-3294
[email protected]
http://www.davessmallbodyheis.com/

I will posit my opinion on head gaskets, camshafts and rocker arm assemblies.

Originally, the head gaskets were copper clad and that is what I used for 44 years. Insisted on it, right up to the point I had a failure in 2021. I had used a new, but old stock Victor copper clad gasket. the copper cladding failed just enough to allow a little combustion into the cooling system, enough to cause the motor to always run hot, over 190 even on a cool day. I have a stash of these old copper clad gaskets but I am not 20 any more and muscling these heads on and off by myself is not the easy task it once was. So I decided to go with a fresh Felpro Blue head gasket. Worked perfect. So rather then beat the bushes for a copper clad gasket, go with a new fresh Flepro Blue head gasket.

Camshafts, new cores have been diabolically difficult to come by the last couple of years. That being said, there seems to be a real problem with new manufactured flat tappet cams and lifters failing. I think its a combination of less then adequate metallurgy and less than adequate machining. The stock original cams have CWC (Campbell Wyant and Cannon) and maybe CMC (Camshaft Machine Corp) cast on the cam. CWC cast the cam blank and CMC machined it. The cams had excellent metallurgy. So send your stock cam out to a experienced cam grinder and have the original cam reground. I have used Schneider Racing Cams in San Diego for a couple of decades now (they can do a stock grind to a race grind). Be forewarned, the word has gotten around that they can regrind our six cams so they have been on a roll recently with our cams, lol. Excellent workmanship though.

Rocker Arms, if yours are in decent shape, not loose and not wearing into the shaft, then you might just need some cleaning. But if the adjuster balls are not balls any longer, or the rockers have really dug into the shafts, put a few dollars aside and send the entire assembly to Rocker Arms Unlimited in California. They are the only outfit rebuilding these style rockers and they have the ability to re-hard chrome the shafts and get the rockers in to the correct specification. Its a small thing, not exactly inexpensive, but all the small things are cumulative to getting a good running motor.

You probably have a Rochester 1bbl. I'd look for a Carter YF made for a comparably sized inline 6. Since some folks around here are fans of dual carburetors and dual exhausts, I'll just say I prefer the stock approach.

I like the HEI distributors and have been converting a few Chinese made ones to work on the 216/235/261. So far that has been successful and it has been a cheaper alternative. They're coil in cap, copies of GM products and if it is important to you to have a separate coil you can use standard GM distributor caps and rotors on these distributors. You can also use standard GM parts inside. They're ugly, but so am I and I'm not doing this to win a beauty contest nor a car show.

I agree with Mike...I'd get your camshaft reground and I'd get new lifters.

I'm a fan of low psi electric fuel pumps...the AutoBest F4027 particularly. I've used this pump since 1997. Mine outputs 3 to 3.5 psi which is what you need.

Gaskets...aside from the head gasket they're pretty much all the same. Fortunately I haven't had the failure Mike mentioned. But I used a "perma-torque" regular gasket in a 235 and never had any problem for nearly 30 years. I have a copper clad Fel-Pro head gasket in mine now. Get a fly cut on your block and head to make sure both are flat.

Your engine is going to be okay with a two-piece rubber rear seal gasket...some call them neoprene but it was a different compound than that...a variant of Viton I was told years ago by Fel-Pro. No matter what you do consider please installing a Speedi-Sleeve on the back of your crankshaft. Use some red Threadlocker on it. If you do that the rubber seal will work well or if you can possibly do it, there's a one-piece seal that requires machining but will stop rear main leaks completely. Jerry can tell you more.

Rocker arms have been the topic of recent discussion. There are some folks here (including me) who'd like to make roller bearing rocker arms (and it can be done) but there are some limitations. I'd check the ones you have carefully. Watch eBay. Every once in a while a new set of shafts and rockers appears.

As for heads, I'd look into installing bronze guide liners. They'll work better for you. I'd get new springs, washers, etc. Please don't worry about hardened seats unless you don't plan on using gasoline. I'd look at my old valves carefully. Replace them if needed.

As for re-boring, I would hand the pistons to the machine shop with each marked on the top with a Marks-A-Lot numbered 1 through 6 and I'd tell them I wanted each cylinder bored and honed so that exact GM specs are met. And if they acted odd or like they didn't understand I'd leave and find somebody else to do the work. I mention this because I've seen blocks bored so poorly and sloppily the engines would have run as if they had 20~30,000 miles the first day they were started. Mine was done to specs and has between 148 and 155 psi.

Alternator...definitely. Generators are fine but generator & starter shops are not common any longer and if you decide at some point to install A/C you won't have a power problem.

What else? That's about all that comes to mind quickly. I'll let you know if anything else occurs to me. Good luck!

Will Schneider regrind lifters as well?

And if you haven't already, be sure to check out our 261 Rebuild Tech Tip A few bits of info you might find helpful.

If they don't regrind lifters,(or are too busy to) I can do that with a fixture I made for my lathe, and a tool post grinder. I can either finish the bottoms of the lifters flat, or with a slight convex radius. I've seen new lifters made both ways.
Jerry

Thanks all for the detailed responses, definitely lots of good information and lots to think about.

I have read the tech tip probably 3 or 4 times and have also read Deve's book a few times as well as his website.

Jerry at Schneider was sending lifters out to be reground but the fellow sold the machine to somebody in Washington? Oregon? Somewhere and now he has no way to resurface them.

Interestingly enough, Rocker Arms Unlimited can regrind the lifters.

http://rockerarms.com/pages/lifters.html

Deve's book can serve approximately the same purpose as last year's Sears Roebuck catalog once did in the "little house out behind the house" for people without indoor plumbing. Exercise an appropriate amount of caution when using it as a reference manual!
Jerry

If you have the main oil gallery drilled for an external filter, consider the plumbing. If you use a dual exhaust setup the plumbing becomes more of a headache. Whatever you do, be sure to use 1/2" ID hose and protect it from manifold heat; braided line and AN fittings is best. Make sheet-metal heat shields if necessary. Also consider that the filters available by application for Mopar products (a common application for aftermarket remote filter mounts) are rather coarse, something on the order of 30 microns, so they will flow enough oil. There is a Wix number 51515, also under NAPA with a similar number, it is much finer and is physically larger so even so there's not much pressure drop across the filter. Hot Rod Lincoln says there are low-micron hydraulic system oil filters available but I haven't looked. I found a Franz toilet paper filter and added that as a bypass filter. Oil stays pretty clean.

I also installed a spin-on coolant filter with sacrificial zinc in it to prolong the coolant change period. Dodge application, I think but suitable for systems up to 4 gallons. That way I don't have gallons of spent coolant to dispose of as hazardous waste. My filter nount came off a 220 Cummins stationary engine but you can use the same remote mount as for the oil filter.Put a shut of valve on both sides so you can take the filter element off without losing coolant. I had the radiator cap off the other day and shined a flashlight down it. Clean as a whistle and has not been to the radiator shop in decades. My incentive for the filter was the amount of hard black sludge in the back corner of the block by the drain cock. I had to use compressed air to blow a channel so it would drain. Same story on my 235. The filter should catch that before it has a chance to settle out.

These engines came from the factory with exhaust-valve rotators. They greatly extend the live of valves in heavy service. I'd be surprised it your engine doesn't have them. If not, find some if you're going to put it to truck duty. Yes to bronze valve guides and also positive stem seals. The machine shop can cut the guides to take these. Don't get the exhaust stem-to-guide too tight. They will hang open if they get too hot, scare you with the noise and maybe bend a pushrod. Happened to me near Salton Sea (-200ft. elevation) on a cold, clear morning, i.e. dense air, lean mixture. I'd tuned for 3,000 ft. No pushrod trouble though.

Good to know.

I’m not sure this flat tappet nightmare is ever going to get corrected. There might be some improvement in the super common, higher volume, engines like SBC, BBC, SBF. I know Comp had released some stuff with DLC coating. And there’s a lot of momentum in the direction of retrofit roller cams in those engines that might render flat tappet obsolete in those segments.

For those of us who like to play stuff a little further on the fringe (like a 235 Chevrolet)….cam and lifter regrinding might be about the best available option. And I’m not sure in 10 years, how many shops will still be doing that. Aren’t too many even of them even left today. Really need a aftermarket roller cam solution for stovebolts that doesn’t require a bunch of ultra-custom machining. I kinda doubt that’s very high on any company’s radar. However, we are blessed to be in the same boat as the 6 cyl Tri-five car community. Maybe there’s some hope.

My “runway” in this hobby is a little longer than some. I do occasionally think about how sustainable it will be, as I enter retirement years.

Schneider says they can put a roller lifter profile on a Stovebolt cam- - - -but it needs to be a steel (not cast) cam core to survive for more than a few minutes of operation. Fortunately, there are still a fair number of forged steel 216 and spray-oiler 235 cam cores out there, and they can be sleeved up to fit 235 cam bearings. A thin seamless steel tubing sleeve in a stovebolt lifter bore can make a MOPAR big block roller lifter fit, and center up on the cam lobe. I just converted a 216 block to those lifters recently, and I'm getting set up to run Torrington needle bearings in stock stovebolt rocker arms.
Jerry

Hydraulic lifters cant be trusted either. My friend just had his total restoration job on a '72 Blazer with a 350 self destruct the top end in about 40 minutes when the hydraulic lifters failed.

Summit sent him a new roller cam set lifters, etc totalling over $3500. So far, so good on the new higher end parts.

They obviously were aware of the problem because they barely put up a fuss over the claim.