The Stovebolt Site Forums The Shop Area Engine Shop 261 info

Since (with the help of others) I have determined I have a 261, I need to find some info on this engine. On the 6066 gmc webpage it has info for all inlines but this one. I would like to fond out torque and hp ratings to see if this is the engine I want. Does this engine compare to the 292?? Does it have the low end torque and is there room for improvement?

Also the book: Chevrolet Inline Six Cylinder Power Manual has been highly recommended but it doesn't look like it covers 261's. Does anyone have input on this??

Thanks
az

Santucci's book is mostly for the L22 series (194/215/230/250/292) engines. If you look around on eBay, there is a '50s book (reprint) on tuning old Chevy and GMC engines that shows up from time to time.

261 advertised HP is 150 at 4000 rpm,torque,235 lbs ft at 2000 rpm. The one and only reliable 50's dyno test of a stock 261 showed 114 actual HP at 3500 and the torque was 200 at 2000 rpm.For low speed engines like these, all they have is low speed torque.
I have 2 good running 261's in Pu's one is more or less stock,the other has a mild cam,cast iron headers and a 4 bbl.The modified engine pulls as good as the stocker down low and is way better over 3000 rpm.
I would say stock 292 makes more pulling power, and yes, Leo's book only covers the later 6's.You can look in the old 50's 235 tuning books or buy a May 1955 Hot Rod magazine on Ebay, the book has the only good 261 modifications and dyno tests available.

So the may 1955 hot rod magazine is an issue worth picking up?

Are this issue and the "How to Hop Up Chevrolet & GMC Engines" book the best resources for the 261??
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Thanks
az

Or you could join Inliners Int. and as a member write one of our technical advisors. The old hop up books are ok but a few things have changed in the 50 plus years since those went to print. The 12 Port News has had many articles on building the 261s, some of those are still available in the back issue stash.
Best of luck.

Inliners has a new "formula" out for the 261 that uses commonly available Cadillac pistons and rods on an offset ground 261 crank to make a higher revving more strokey engine with lighter rotating parts to make big torque. It's not on their website, though, you have to buy the backissue newsletter. It's supposed to be quite a package.

thanks for the 261 info. i got mine by accident. rebuilt it 30 over,cast pistons,hydrolic vavles, a small,new holly 4bb,clifford intake,mallory elect ignition. everything balanced. just got it going in the ol'40 ,stock, truck. I'm afraid if that 4bb kicks in the motor'll shoot right out the grill. Boy,does this thing run !

They are nice and torquey. I have been hauling a bunch of firewood in my truck lately and it doesn't even break a sweat. Mine is stock.