273 rebuild

-
64barracuda

64barracuda

Well-Known Member
Joined
Aug 3, 2010
Messages
48
Reaction score
0
Location
minnesota
What is the biggest I can bore my 273? Would it work to make it into a 318 or maybe a 360?
 
I wouldn't go farther than .030 without having it sonic checked by your machine shop. They cannot be bored to 318 size. toolman
 
I agree with toolman mike, I had one bored .040 years back and soon after it was running, #4 cylinder started missing. Pulled the plug and got water. Needless to say, the cylinder was cracked.

Bill S.
 
64barracuda said:
What is the biggest I can bore my 273? Would it work to make it into a 318 or maybe a 360?
Click to expand...

The short answer is no. We always tried to get the smallest bore to have the strongest block. Nothing wrong with a 273. They have many advantages over newer engines. If you want more cubes then watch and get what you want. 318's and 360's should be easy to find and pretty reasonable. 318 uses the same motor mounts as the 273. The 340 and 360 motor mounts are different but close.
 
I wan't looking for more cubes I just thought it would be easier to find parts for if I went to 318 but I guess that is unreasonable. I thought the 273 to 360 had the same block but I guess not. I don't know alot about this stuff but I want to rebuild my 273 which is a 64 model so I can keep it #s matching. I don't know if a crankshaft from a 318 will fit or if it would push the piston too high. It would be nice if someone has done this before who could help me out. I suppose I will leave the valves or just replace with the same size so I can keep the heads.
 
you can use a 318 crank in a 273 they interchange in fact many people put 273 cranks in 318's because most 318 cranks are cast and early 273 cranks are forged, just like the good 340 cranks, so I would recommend keeping yours, as far as valves the stock size are great for a 273 in fact if you try and install larger valves they tend to hit the cylinder wall, a stock cylinder head rebuild with unleaded valve seats should do the trick, the hardiest part to find are going to be pistons as 318, 340, 360, pistons can't be used, high compression 273 commando pistons would be a nice choice,
try calling EGGE http://egge.com/
 
If you want to keep the 273 for originality just take the engine to a machine shop and they'll know what to do. 273 and 318 cranks are basically the same. Your stock crank is forged steel and is a good one. No need to switch cranks. The connecting rods are also good. They are strong and light weight and are bushed for full floating piston pins. The heads can be rebuilt as needed and suit the 273 fine. The block will probably need bored and pistons can be found at Egge Machine. They have both the low and high compression pistons available along with the proper rings for the job. Machine shops have their own suppliers for parts but they may not be able to find 273 pistons. That's where Egge comes in. They will have everything you may need. Here's a link to my 273 build that may answer some questions. http://www.forabodiesonly.com/mopar/showthread.php?t=94343 toolman
 
Thanks alot, you guys have good advice. I am looking for the absolute cheapest build that will perform and is done right. Should I grind the old valves or get new ones of the same size? Egge is at $430 for new pistons but Im not sure if I can afford this. They have two models L2221 and L2222 or something, is the difference the compression? Why would someone buy low compression if high is the same price? Does anyone else have pistons for cheaper? What other internal engine components should I replace? Thanks again for the help.
 
I would say the key words are "cheapest" and "done right." Be prepared to spend at least a couple thousand. At least. If everything inside is close to specs you may be able to just hone the block and freshen it up with new rings bearings and gaskets. You can grind the valves too and call it good. But, you get what you get. When I rebuilt mine, there was too many thing worn out so most everything got machined or replaced. You will have to be the judge as to how much money to spend depending on what the engine needs. Mike
 
Well if you saw the car that the motor is in I don't think a few thousand would make the car worth that. I dont want to over spend and I was thinking maybe a budget of $800-$900 would be good for the motor then I could move on to trans, most of the work will be by my own and I have most other parts for motor. I dont have money to poor into it Im only in highschool. By the way thanks for the link. It helped quite abit although I couldn't follow all of it yet.
 
64barracuda said:
Well if you saw the car that the motor is in I don't think a few thousand would make the car worth that. I dont want to over spend and I was thinking maybe a budget of $800-$900 would be good for the motor then I could move on to trans, most of the work will be by my own and I have most other parts for motor. I dont have money to poor into it Im only in highschool. By the way thanks for the link. It helped quite abit although I couldn't follow all of it yet.
Click to expand...

Does the motor run? If it does just tune it up and make it run as good as it can. Makes sure it is safe to drive. When I looked at mine before I bought it, we jumped it and trickled gas down the carb to make it run. I spent around $1000 to make it start and run, stop and steer. It was safe and dependable and I drove it that way for 4 years. You may want to go that route. I'm impressed that a young lad is passionate about old Mopars. Good luck and keep us posted on your progress. Stick around here. Lots to learn. toolmanmike
 
I'm pretty well known fro not telling people what they want to hear, so let me offer a "reality check". I certainly don't wish to discourage a "young gun" from getting into this hobby, but rather wish to impart some wisdom learned from making some of the same mistakes in my youth.

First off, EDUCATE YOURSELF. Get and thoroughly read "How to Rebuild your Small Block Mopar" by Don Taylor/Larry Hofer then get "How to Hot Rod your Small Block Mopar" by Larry Sheppard. This and other forums on the internet certainly also contain plenty of "free advice". A factory service manual reprint is also a must.

A 273 will be more expensive to rebuild than a 318 or 360. Why? Because they were the least produced LA engine, and have been out of production the longest. Parts such as pistons are low sales volume pieces, made in small batches by very few suppliers. Basically a custom part. Egge's prices are quite reasonable for what you get, and their customer service is good. I've ordered from them myself.

If your budget is only $800-$900, strike the word "rebuild" from your vocabulary. You can't get there from here. You MIGHT be able to overhaul or "freshen up" an already running engine for this, but even then I have my doubts. By overhaul I mean a complete disassemble, clean, inspect and reassemble replacing only those parts which are damaged or worn beyond spec. Figure a complete gasket set, rings, bearing inserts, timing chain and a valve job. Machine shop labor should be a quick bore hone and crank polish. The above assumes the bores and crank journals are reasonably round and taper free. Head work will be at a minimum new valve guides, valve and seat resurface, and spring shimming. Add $$$ for new valves if the current ones have worn stems, are burnt, bent, or have already been ground. Heads can suck up $500 real quick.

$800 should buy you a running 318, and a couple cans of red paint. If you have an auto, you may have a converter hub miss-match, but this is fairly easily dealt with.

There is no such thing as "numbers matching" before 1968. So don't lose any sleep over that. Anybody who is smart enough to tell a 318 from a 273 by looking at it won't bother asking you what you have, or if it's original.

If you don't want to "over spend", stop right now. We're talking about a 47 year old economy car which was never "rare". If you want to fix up and drive an old Barracuda, that's a noble goal, and you can have a lot of fun doing it. But I cringe when I hear people talk of older cars as an "investment". I have exactly one 1965 Dart in my portfolio, and it is most certainly in the liabilities column. See my signature below.

If the 273 runs now, spend your money rebuilding the front end and getting rid of those 9" front drums. If the car has typical Minnesota corrosion, consider spending the cash on a rust-free body sooner rather than later.
 
The motor is stuck so not even close to running. Im going to tear it part, change all gaskets, most likely get new valves and seats, bore it, new pistons and rings, all new bearings, and check if crankshaft and rods are ok., from then I dont know what to do. I have readily available 318s in my family but just wondering, how would you fix the converter problem? I will have to leave the original trans(push button) in because how could I change it in that car? I thought the original motor would make the car worth more anyways. Yes I know about Minnesota rust but it will get taken care of. The glass makes this car worth. I probably wouldnt consider one so old either but it is a barracuda. Right now I have to start from scratch. I might consider selling this when Im done to work on a different car but it is gonna be another mopar. Almost everthing will be replaced if not all at once. Right now I am working on the motor situation and I might use a 318 but Im not sure right now. After all I only paid $200 and have $120 in parts so Im not too deep and I can ditch it at any time.
 
If you havent got the engine apart yet you don't have enough information. You may find it unfixable or you may find it buildable. I agree with the previous posts on the cost thing though. I have my 273 ready to put together after complete machine work on the crank, block & heads with the HP Egge pistons and the money was signigicantly more than your budget. You may be able to clean things up, hone it and mic it our and the rotating assy will be ok. The thing you can't escape is the headwork. That engine does not like today's gas and the only fix is valves, guides and seats and that will cost. Good luck with your build though, it is a ton of fun if you can do it.
Rat:arrow:
 
By only buying pistons, rings, gaskets, bearings, valves, seats and other valve parts I can make maybe within just over $1000 but yeah I havent checked the crankshaft or rods or anything yet. I think it would perform well with these new parts. I hope to rip it apart after I can blow some snow to reach the car and get it into a shop. If something is terribly wrong I guess I will swap it.
 
A running 318 swap would be a lot less money than a 273 rebuild that needs boring & pistons. (Rebuilds have a way of snowballing into more parts and money) A 318 bolts in, use the 64 exhaust manifolds and 64 brackets and linkage; crankshaft will need a bushing to fit the hub of your auto trans converter. It has more torque and horsepower, fun to drive but won't break parts. Hang onto the 273.
 
You must log in or register to reply here.
-

Back
Top