Stovebolt.com Forums The Shop Area The Engine Shop 261 rebuild

i have a stock 60 261. runs but is low on pressure in #4 and #6. want to rebuild and hop it up a little for my 46 1/2 ton resto rod. just want to know if anyone can recommend any particular parts or vendors that they have used. top to bottom i would like the build to go like this:

848 head w/ new valve and seats ( original rockers and push rods could/should be used?)
check and deck (if necess) head and block (adds to compression anyway)
offenhauser intake w/ dual carbs (i have heard use carbs from 216 motors to avoid over carbueration)
fenton (or similiar headers)
60 over bore (obviously new pistons and rings, will the old rods work, should the crank be ground and balanced?)
3/4 grind cam (new lifters)
new/rebuild oil pump
short shaft water pump and pump relocator (to fit the 46 stock front and radiator)

i believe thats it. have read and asked a lot to come up w/ this set up. this is my first engine rebuild, so any and all info and thoughts are muck appreciated.

thanks...big ed

Ed,

You should have an enjoyable time sorting through the variety of responses that you will get on this one (and reading all the previous posts on this topic).

One thing is certain, the 261 engine is a jewel of a replacement if you want an improvement but want to stay with a stovebolt engine.

848 head w/ new valve and seats ( original rockers and push rods could/should be used?)
> 848 head - Yes, if you have one readily available : just drill the coolant holes to match the 261 - this head nicely increases the compression of the 261 (which is lower than the compression of the 235)
> hardened valve seats - your choice (if you will be high-revving and racing, Yes)
> get new valve springs (Patrick's os a good source of 261 parts and advice)

check and deck (if necess) head and block (adds to compression anyway)
> check - Yes; deck - ??? (others might comment on measured benefits relative to costs)

offenhauser intake w/ dual carbs (i have heard use carbs from 216 motors to avoid over carbueration)
> dual carb manifold - yes, for cool-factor and power
> Offenhauser, Fenton, Clifford, other - your choice (how they look, how they are warmed, and carb mounting posts are points for consideration)
> carbs - I've used original 261 Rochesters and Carter-Webers without problems and with good results (Tom Langdon is a good source for information and parts) - all 216 and pre-1950 235 carbs do not bolt-up to the newer 235 and 261 intakes
> warming - Yes : exhaust gases or cooling system fluid - different intakes and adapter plates work better with coolant vs exhaust gases.

fenton (or similiar headers)
> Yes - whatever suits you (note: new Fentons now seem to come with that black EDP(?) coating (says Chevs of the 40s) - too bad)

60 over bore (obviously new pistons and rings, will the old rods work, should the crank be ground and balanced?)
> 60 over bore - your choice - mine is 60 out of necessity. Some people go for overbore-power; some people are conservative, and leave metal for future rebuilds.

3/4 grind cam (new lifters)
> Your choice - the stock cam is slightly modified from the standard 235 cam (it's nice to state that it was good enough for a 53-55 Corvette's 235) - the measured benefit of a different cam relative to cost would be interesting to see

new/rebuild oil pump
> Yes

short shaft water pump and pump relocator (to fit the 46 stock front and radiator)
> relocator plate - Yes; original-style 1955-1st or earlier pump with the plate has the appropriate shaft length and would be in the correct location (maybe this is what you mean).

- drill the snout of the crankshaft for a balancer tightening bolt
- drill the cam/crank gear cover/etc so the bolts on the lower two bolts may be installed from the outside
- What will you use for the full-flow oil filter (as was standard in 1960 261s)?

Tim

Most likely you have read this old article?

Patrick's

Langdon's

That's a fantastic article I have read over and over again which has provided invaluable information regarding the effects of modifications. My favorite sentence:

After the last test, the engine was removed from the dyno and installed in McGurk's '52 Chev 1/2 ton pickup truck.

It seems you're looking for that period look and Tim's advice is right on I think. If you decide to have a more modern look, consider a small cfm 4bbl and Offy or Clifford intake.I've been rebuilding a former 261 drag motor for some time now and it's always great to hear of other 261 projects in the works.

thanks folks, i am hoping for a large response as well. the more ideas and info, the better the chance of building something really nice.

Do not use carbs for a 216. The bolt spacing is different and will not fit on the Offy manifold.

I sent my 261 to JASPER engines for a rebuild several years ago. It runs like a rocket and has a 75,000 mile warranty!

Check out my Webshots and see what I did....

sweet....nice motor. did you change the water pump to a short shaft or is it original? can you give me some specs on the rebuild as far as measurements and possibly parts manufacturers that were used. if you don't mind me asking, what was the finally cost to have jasper do it. thanks....big ed

big ed,

The first dual carb set-up I tried on a 261 was with dual Rochesters : Driver Side of Engine and Passenger Side of Engine

Then, I had a chance to drive Sweet's Carter-Weber dual carb 261 and decided to put a 261 back into my 1954 Suburban because its old 235 was down to 0-5 psi oil pressure.

When I reached the point of adjusting the dual-carb linkage, Fla54Chevy3100 posted a link to his Carter-Weber set-up on a 235 (and he also has some photos of a dual-Rochester set-up (235?) ).

Here are some photos taken last summer while re-doing my 261 with dual Carter-Webers, Fenton intake, Fenton exhaust, oil-bath air cleaners adapted for modern filter inserts. (part suppliers were linked in my earlier post)

Tim

Ed

I do have the short shaft pump, but I have plans to remove it and install the original using the relocating plate that many have written about. Reason being is that my truck gets a little warm when sitting a idle for a period of time.

The engine is bored .040 over. The nice thing about JASPER is you remove the engine from its source, take all the accessories off, give them the head, block, and oil pan and all parts in between.

They will come pick up the motor, and I had mine back in 3 weeks (over the holidays in fact). They even called and told me they had to replace the oil pan due to corrosion. When I asked how much more that would be they said no charge - they were just curious where I wanted the drain plug location. As far as cost, I don't recall exactly, I think it was around $2300.

this is getting cooler by the post.

TC did you make the oil filter assembly yourself or did you modify some one else's product. a very nice set up. thanks for the links, i will be taking a look at those pics very closely.

sweet what are your plans for the short shaft. if this is a near future swap for your pump, might you be interested in selling it? definitely need one to shoe the 261 into the 46. is your pump a shortened shaft from an ealier 261 or is it an aftermarket pump. i will probably need the relocator plate as well. i have read that the 261 placement in a 46 leaves the pump low and does not draw through the radiator as well as it should.

thanks again for the assistance big ed