z_daddy
z_daddy
Is there a certain way the pistons face, and how about the rod bearings is their a certain way the go in too 273 std bore engine
Piston and rod bearings installation
- Thread starter z_daddy
- Start date
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On some pistons, yes. If they need to be "oriented", look on the top of the piston for a notch. That goes toward the front of the engine.
Now for the connecting rods. You install the rods so the squirt holes point to the center of the engine and the anchor slots are on the outside. Always match the anchor slots up with the rod and caps.
Same with the main bearings, the anchor slots in the block and the caps must butt together on the same side.
Also, before installing your pistons, make sure that all of the rings spin freely in the ring grooves of the piston. Then right before you install them, make sure that the top and middle ring end gaps are at least 90° apart from each other. Same with the thin rings on the oil ring, make sure that the ring end gaps are at least 90° apart from each other.
Now for the connecting rods. You install the rods so the squirt holes point to the center of the engine and the anchor slots are on the outside. Always match the anchor slots up with the rod and caps.
Same with the main bearings, the anchor slots in the block and the caps must butt together on the same side.
Also, before installing your pistons, make sure that all of the rings spin freely in the ring grooves of the piston. Then right before you install them, make sure that the top and middle ring end gaps are at least 90° apart from each other. Same with the thin rings on the oil ring, make sure that the ring end gaps are at least 90° apart from each other.
IIRC, 273 2bbl pistons have 4 valve reliefs, so it looks like they can go either way. But there is still a front and a back for each piston -- the piston pin is NOT centered in the piston. The "extra" valve reliefs are just because they didn't want to cast different pistons for the left and right banks -- you just "turn them around" for the other side.
I've heard of the reversing the piston trick, but I don't think it's worth the wear and tear (piston slap) on a stock 273.
The hi-compression 273 domed pistons are different for each bank, since the dome is off-center and they only have one set of valve reliefs. These you definitely cannot reverse, except by swapping side to side.
I've heard of the reversing the piston trick, but I don't think it's worth the wear and tear (piston slap) on a stock 273.
The hi-compression 273 domed pistons are different for each bank, since the dome is off-center and they only have one set of valve reliefs. These you definitely cannot reverse, except by swapping side to side.
The wrist pins are offset. You could put them in backward and get a little more bang for the buck... short term.
I cant say why I decided to post to this thread. Anyone who intends to build and engine should first buy the "How To" book. Sure you can get answers to those questions you pose but what about all the details you fail to question?
Good luck
I cant say why I decided to post to this thread. Anyone who intends to build and engine should first buy the "How To" book. Sure you can get answers to those questions you pose but what about all the details you fail to question?
Good luck
pishta
I know I'm right....
Single valve reliefs inboard, rod squirters inboard and bearing tang to bearing tang.
z_daddy
z_daddy
Thanks to all of you that replied
z_daddy
z_daddy
Need help the shop I took my parts to be cleaned mixed the rod caps up there is no numbers I can't seam to tell which ones goes on the rods suggestions need help :blob:
Are you sure they are not numbered? Best choice now, is to see if there are any marks or features that would tie one to another. The real test is to measure them, torqued, with a dial bore gage. Also I would never return to that machine shop.
Ok. first line up the rod and caps in the proper orientation.
sometimes the rod and caps are marked on one of the ends from the factory.
Or else, you will have to do the "Puzzle".
Put the cap on the rod and look for a chamfer on the end of the crank bore. If there is a chamfer, make sure that it matches up with the chamfer on the rod, or else try another cap until you get the best match.
If you can't figure out which rods and caps go together. maybe ask the machine shop to figure it out or recondition the rods (with new bolts) at their expense for mixing them up on you. They need to learn from their mistakes.
67Dart273
Well-Known Member
I missed this. You mixed the rod caps up?
Then if you cannot figure out for certain which rods they fit, you need to have the rods reconditioned or replaced
Take your time and be careful. Look for identifying marks. Numbers, stampings, even scratches that match up one rod to one cap.
nothingbutdarts
Well-Known Member
nm9stheham
Well-Known Member
As above.... once the caps and rods are mixed, they HAVE to be sorted out or reconditioned. They are machined together and if mixed the cap will not match up rigth to the rod and the bearings will be sieze to the crank when tightened.
I am trying to think of a good way to do this. I would try to:
- Take one rod and try each cap on it one at a time (torque it down with the bolts each time) and see of there is a ANY 'step' in either 'matchline' where the caps meet the rod on the inside of the assembly where the bearings set. ANY step, even .001" means you do not have a match.
- For the first rod, go through all 8 caps and find the one that matches exactly. Set that aside as one assembly and then start the same over and over with each successive rod.
- You should find and exact match for each one.
The problem above is finding a way to measure precisely any 'step' at the matchline of each rod assembly. You can feel a step of .001 to .002" with your fingernail but I am not usre that is good enough. A dial indicator would be good but many do not have that. Maybe someone has a good idea on how to make the measurement.
I am trying to think of a good way to do this. I would try to:
- Take one rod and try each cap on it one at a time (torque it down with the bolts each time) and see of there is a ANY 'step' in either 'matchline' where the caps meet the rod on the inside of the assembly where the bearings set. ANY step, even .001" means you do not have a match.
- For the first rod, go through all 8 caps and find the one that matches exactly. Set that aside as one assembly and then start the same over and over with each successive rod.
- You should find and exact match for each one.
The problem above is finding a way to measure precisely any 'step' at the matchline of each rod assembly. You can feel a step of .001 to .002" with your fingernail but I am not usre that is good enough. A dial indicator would be good but many do not have that. Maybe someone has a good idea on how to make the measurement.
Good advice above especially from Redfish. Get a "how to"book and study up!
Recondition the rods to do it right. Pistons should go in only one way as well as the rods.
As mentioned, rings need to be oriented so the gaps aren't lined up. The end gaps should be checked also. There are too many details that need to be done to do the job correctly.
Recondition the rods to do it right. Pistons should go in only one way as well as the rods.
As mentioned, rings need to be oriented so the gaps aren't lined up. The end gaps should be checked also. There are too many details that need to be done to do the job correctly.
67Dart273
Well-Known Member
No kiddin. Some of what I remember "getting in late on" my days at the Miramar hobby shop
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1.....Some guy had a 67 GTX 440. I asked him what he was up to. "I'm pullin the engine to replace a bunch of gaskets, I've got oil leaks."
A few days later (this was part time) I was back in. He had a huge giant stack of Fram air filter boxes. He had dug them out of the trash and was MAKING engine gaskets from them!!!!
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2.....Art Emline, the thievin' bastard who stole some of my tools, put together a 396 and into a 57 Chiv. One Sat I was busy all morning. He had borrowed a spare coil, asked me some questions, finally came and said "I really need your help it won't fire."
I KNEW the damn thing should run, I helped him put it together and installed and lashed the cam.
He handed me a Pepsi can----"hasn't got gas yet, prime it with this." I smelled it to make sure. Told him, "go get me some gas." The can had JET FUEL in it
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3.....Friend was re-ringin' a 318 Poly. Had it on the stand putting the short block together. Came over, "I got about 4 pistons in, now it won't turn" He had not cleaned the ring grooves before installing the rings
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4....Some sailor got a SB Chivvy all together, painted, in the car, installed, and noticed HE HAD LEFT OUT THE OIL PUMP
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5....Putting rags into the carb intake ports is a great way to keep junk out of the engine. LEAVING them there when installing the carb is NOT so great.
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6....There were countless, nameless guys who managed to get a complicated piece like an engine out of the car, apart, overhauled or at least replace the short block, get it all back in, together, and not too many nuts left over. BUT THEY COULD NOT figure out how to time the damn thing. That is the reason I am so good at things like piston stops and initial fire-up. I taught myself how to do it. I've no idea, anymore, who taught ME the "finger in no1 spark plug hole" trick.
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7.....I myself made a real dumb *** mistake with the 440 in my old 64. I had scored a used mechanical cam. "It was huge." I was trying to get it done and fired, and was pushed for time. Turns out I dropped one plug putting it in, retrieved it, and installed the plug. I had droppped it right on the tip and pounded the damn gap shut. When I fired it up it took me some 5 minutes to figure out that .......it wasn't the big cam..........it wasn't the firing order.......is simply was not hitting on one hole. Most of the eggs standing around just thought it was a real wild cam, LOL
Lot's of laughs there! I have a few stories myself. It is a big and complicated job building a engine. Too much detail to put in a paragraph. That's why they write books about it. And don't forget the oil galley plug under the rear main bolt hole and did the distributor bushing get replaced and properly sized? tmm
67Dart273
Well-Known Member
and the "dual" oil plug goes in from the rear of the block?
How about the proper way the rocker shafts are positioned. They can go in 4 different ways but only one will work.
Or the two that go behind the camshaft thrust plate. Our first engine, the machine shop left those out and had low oil pressure until I found they were left out and replaced them. It only took pulling the engine 4 times, and then finally making my own priming shaft (they were not made back then by MP) to find the problem.... :banghead:
They were not used in the old engines. The machined thrust plate sealed them. Don't beat yourself up on that one.
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