261 ci chevy piston

johnnycanuk · Member

261 ci chevy piston

wuga · PRINCE EDWARD COUNTY, ONT

Just bought a set of .060 over from these guys shipped by USPS to a drop in Buffalo. Pistons look great and the price with shipping was dirt cheap. They sell the pistons by single units as well. www.northernautoparts.com/part/sl-92p30

Warren

johnnycanuk · Member

Thanks for the info. I will check it out Warren. I would prefer to complete the set as replace the whole lot or have a mismatch but it is an option. John

johnnycanuk · Member

Thanks for the info. I will check it out Warren. I would prefer to complete the set as replace the whole lot or have a mismatch but it is an option. John

toomuchjunk · S/W ONTARIO

I can't remember what I had for supper so I could be wrong and it doesn't really matter only in my small mind but wasn't a 261 a Pontiac engine?? My first car was a '55 Pontiac with a 261 thats why it kind of stuck
TMJ

slim · DUNDAS, ONT

Chev engine used in Canadian Pontiac's from 55 to 62 big bore 235.

wuga · PRINCE EDWARD COUNTY, ONT

Chev pickups used the 261 somewhere between 1955 and 1962. The 261 was developed as a truck engine.

Warren

fleet 51 · PORTLAND, ONT

The 261 definitely was used as the " entry level motor " in the Canadian Pontiacs from '55 to '62 -- I believe all of the V-8's were Chevrolet units , as opposed to the U.S. cars , which were completely different castings ( and NO inline six cylinders ) --- LATER -- DON / fleet 51

johnnycanuk · Member

Thanks to all who replied. I am going to search for awhile longer for an original Alcoa #1159 before I throw in the towel. If you hear about one please holler!! John

fleet 51 · PORTLAND, ONT

HI JOHNNY : It looks like you should communicate with WUGA -- His info sounds very solid . However , I am a member of " INLINERS Int'l " and I can put you directly in touch with Tom Langdon -- ( 30 yrs with G M engine design ) . If Tom can't find it - It doesn't exist !! & he loves Inline engines . Here's his web-site --www.stoveboltengineco.com -- Hope this helps -- LATER -- DON / fleet 51

Don · PRINCE EDWARD COUNTY

1776 sounds like a trw or a silvolite number. The ones wuga got are sealed power. Sealed power or trw would not really be a mismatch as the are very well engineered replacement pistons designed to mimmick the original in every way. If I have sometime this afternoon I will dig out my old machinists books and find the 1776 and see whose it is. TRW is long gone but silvolite is still going and may still make them although they wont be for the deal wuga got. They were almost theft priced and are top quality. Northern did have .030" as well. I have dealt with them. USPS to Canada is easy as well. UPS to Canada, That is a different story! How do I know about these pistons? Cant tell. As for Don fleet51 NO ONE is more passionate about inline 6 cyls. Don and I have been friends since the SR dragster first barked to life. Once he even caught me "road testing" the dragster.
don

johnnycanuk · Member

Hi Don: Thanks for the info re. Tom L. I have in the past talked with him at Hershey. Frankly it had not occurred to me to call him (duh). I will contact him and maybe can see him at Hershey. Thanks again. John

johnnycanuk · Member

Hi Don: Thanks for the info. Actually the no. stamped on the top is 1766, 030. When I talked to Patrick Dyke (Patrick's Antique Cars and Trucks) he was of the opinion they were old Sealed Power Pistons from the no. 1766 but later I found the Alcoa stamp on the inner skirt. He was not sure about the Alcoa name, kind of threw him a bit as he was of the opinion Alcoa never produced pistons. However there are many pieces of Alcoa advertising pistons on e-bay. I have also contacted Alcoa, Pitts. and received a letter back. They indeed made auto pistons, (AWA heads, rods) in the 30's-60's. I have never seen anything but the pistons I have. I know these pistons have been in this block well over 35 years (block also has 56 848 head). I think it was probably used for racing of some sort (came from Manitoba). I guess there are many different ways to solve the problem and buying new pistons or a one new matching pistons probably makes the most sense. However, if at all possible I would like to get a matching Alcoa piston to do this up. Sort of a nostalgic theme I guess. I have a Nicson 2 carb manifold and a matching BXOV Strombergs from an V12 American LaFrance Fire truck (#99 25A). They have 1 7/8 bore.. I also have a set of Fenton (Used) split exhaust manifolds.

I have no idea what this will go in but I have an engine stand and when finished it can live in it and occasionally I can fire it up and enjoy it. I really appreciate all the help and suggestions. It is amazing the interest in the I-6's nowadays. John

Don · PRINCE EDWARD COUNTY

Well it isn't an Alcoa piston, it is an Alcoa blank. I have seen that before. Probably the blanks or castings were made by Alcoa but the machining and finish design is done by sealed power or whatever. Now keep in mind this is coming from someone who has cast a few pistons as well. At one time before many were born we could buy semi finished blanks even from TRW. Even today one could order blanks made at a local foundry or investment caster, specify the mix and they would arrive as a semi finished product looking more like a plug then a piston and would in all probability have the casters mark name or logo inside. The machining is quite anther thing.

my take would be the material is Alcoa lo expansion rate aluminum type 1159. Alco Lo Ex 1159
don

-- Edited by Don on Sunday 14th of September 2014 02:38:55 PM

-- Edited by Don on Sunday 14th of September 2014 02:39:31 PM

johnnycanuk · Member

Thanks for the info Don: I would agree what you say makes perfect sense. That is very likely what I have here. Would also explane why Patrick thought it was sealed power from the 1766 STAMPED on top. Now to decide which way to go. John

Don · PRINCE EDWARD COUNTY

Yes I just looked. My book doesn't have the 261 in it but it does have the 235 pistons and the number for them is 1702.
They changed the number system later. Now I think most are only 3 numbers say like 823P or something. When and why I do not know. When 261s were hot I was not. It took me a few more years to grow up and get my life headed in a better direction. When I worked at Wilsons though we did lot of them for stock cars. I did most if not all the heads for them. Other guy doing heads didn't like anything beyond normal valve job so I got all the fun stuff since I wasn't the boss' son. Turned out to be a good thing.
don

slim · DUNDAS, ONT

Might help if you cant find a match . Trw number is listed as L2033F Im not 100% sure how they dealt with oversized pistons but that is the only number shown. Gm parts list a 30 over 261 as 3758653.

Don · PRINCE EDWARD COUNTY

just add .030"

don