Pistons in hand when boring?

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TrailBeast

TrailBeast

AKA Mopars4us on Youtube
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I remember it used to be that you should have the new pistons before the engine is bored, so the machinist can fit the piston to the bores (or fit the bore to the pistons actually)
Is this still the case, or has that changed?

Thanks Y'all
 
Meh. It depends on how it's done. Most machine shops will bore so that they can sneak up on the actual size with a hone.

I am still old school. I prefer to mic a piston, bore a hole. Number the piston for that hole and repeat. Nothing like getting it dead right.

That said, for the most part, that's not necessary anymore, because modern piston technology has pretty much made sets exact. I still like my way better. lol
 
RustyRatRod said:
Meh. It depends on how it's done. Most machine shops will bore so that they can sneak up on the actual size with a hone.

I am still old school. I prefer to mic a piston, bore a hole. Number the piston for that hole and repeat. Nothing like getting it dead right.

That said, for the most part, that's not necessary anymore, because modern piston technology has pretty much made sets exact. I still like my way better. lol
Click to expand...

That's exactly why I asked, because I thought that it might have changed over the years.
Yea, I like your way a lot better.

Thank you.
 
I like to have them in hand and finish hone to spec.
 
I want them in hand, measure them all then bore to 0.002 and hone to each piston that way the pistons are a good fit and the rings get filed to each bore as well makes for a nicer job and doesn't take much more time. Just my way
 
A bird in the hand is worth two in the bush....
 
But you also need to know how much bore/over bore you are going with before you get the pistons....
 
At the factory, they bore the blocks to the block specs, and the pistons are made to the piston specs. If they are both made properly, they will all work together and not need to be "special fit"....

But for one engine at a time, you are better having the machinist make it to the pistons once you decide what bore diameter you are going with and then order pistons for that. Then he can make sure the pistons will fit the cylinders properly. You can control your clearances better that way....
 
krazykuda said:
A bird in the hand is worth two in the bush....
Click to expand...

Depends on whose hands and what bush. :D


krazykuda said:
But you also need to know how much bore/over bore you are going with before you get the pistons....
Click to expand...

Got it.

krazykuda said:
At the factory, they bore the blocks to the block specs, and the pistons are made to the piston specs. If they are both made properly, they will all work together and not need to be "special fit"....

But for one engine at a time, you are better having the machinist make it to the pistons once you decide what bore diameter you are going with and then order pistons for that. Then he can make sure the pistons will fit the cylinders properly. You can control your clearances better that way....
Click to expand...

See now that's the way I always understood it, and is also why I liked RRR's way.
If I had a choice, that would be the way it would get done, but you know how shops are.
They could bore first, slap pistons in it when they came in and send it down the road.

When I get ready to do it, the shop will get the block and new pistons (hopefully marked per cylinder) and I'll do the assembly.
The little 318 is starting to smoke off and on just a little depending on temperature, and sometimes it puffs a little on warm startups.

I was thinking to just figure out what I need for pistons for an NA daily driver that gets stomped on once in awhile and end up with somewhere about 9.5 to one.
I have a never been installed Mopar Performance cam, hyd lifters and double roller T set already, but the cam is more radical than I can use so I'll probably sell it to get the one RRR recommended or one with about the same profile (semi mild) it looks like.
Something I can keep the converter with most likely.

Might just find a good LA360 and leave it at that, but I'd still want a good running cam in it with a lightly intimidating idle.
I'm assuming that's what cam manufacturers mean when they say "Fair idle"
 
Yeah, the good shops will get the bores close to what you need, then hone them in when you get the pistons...

How big is the cam that you are going to trade off?


Would a set of Rhoades lifters be able to make it better? I just made a post in another thread and a guy challenged me on the Rhoades lifters. I'll go cut and paste it below for you to consider...


BRB....
 
Rhoades pioneered what they call "variable duration" lifters. He puts a groove in them so they bleed down at low RPM and "pump up" by 3500 RPM. They take out about .025" lift and 15° duration at idle and give the full lift and duration of the cam by 3500. They are also anti-pump up. The Rhoades variable duration lifters work better than the others. He patented his groove design which works the best...


Here's their main page:

http://www.rhoadslifters.com/


Part numbers, you want 2018:

http://www.rhoadslifters.com/Pages/PartNumber.html


Here's the page with articles on how they work. The second one is the better one to read.

http://www.rhoadslifters.com/Pages/Articles.html


I've used Rhoades lifters for years. It took me 3 years of looking into them to even try them and now it's all I use. They give better low end torque and horsepower, better fuel economy, without sacrificing the top end. They work with large or small cams and std./high volume- and/or high pressure oil pumps.


I installed a MP .484/284 cam in my 68 340. It barely idled at 1100 RPM at 10-11" vacuum. After installing Rhoades lifters, I had it idling smoother at 800 RPM and 13" vacuum. I'm running a stock 340 with the MP .484/284 cam, stock converter, and 3.91 gear, Holley spread bore Mechanical secondaries and it doesn't bog off the line...

I put them in a 318 with 9.2 compression, stock 340 cam, 360 heads, 4 bbl, dual exhaust and it idled at 22.5" vacuum and got just under 18 MPG highway. I drove it over 300k miles with a set of Rhoades lifters in there.... They last and Rhoades stands behind them.

I got a new one with a pin hole where it didn't machine, back in the 80's. I called Rhoades and described the defect and they sent me one without even asking for the old one back.


They work. Some people don't think that they do, but if you ask people who have used them, they work...


Here's a link to them at Summit Racing:

http://www.summitracing.com/search?S...rhoades 2018
 
Thanks for all that Bruce, and I have considered them in the whole process.
I don't see how a person could argue the fact, because it makes total sense mechanically that they would work like they say they do.

The cam I have now is 497-288 with 75 degree overlap. (a circle track style) that came with new lifters and Mopar break in lube all in the Mopar Performance box.
It was just so cool that I couldn't pass it up, and I figured if nothing else I could use the lifters.
I even thought about having it reground, but the cost is not too far from just getting a new one.




krazykuda said:
Rhoades pioneered what they call "variable duration" lifters. He puts a groove in them so they bleed down at low RPM and "pump up" by 3500 RPM. They take out about .025" lift and 15° duration at idle and give the full lift and duration of the cam by 3500. They are also anti-pump up. The Rhoades variable duration lifters work better than the others. He patented his groove design which works the best...


Here's their main page:

http://www.rhoadslifters.com/


Part numbers, you want 2018:

http://www.rhoadslifters.com/Pages/PartNumber.html


Here's the page with articles on how they work. The second one is the better one to read.

http://www.rhoadslifters.com/Pages/Articles.html


I've used Rhoades lifters for years. It took me 3 years of looking into them to even try them and now it's all I use. They give better low end torque and horsepower, better fuel economy, without sacrificing the top end. They work with large or small cams and std./high volume- and/or high pressure oil pumps.


I installed a MP .484/284 cam in my 68 340. It barely idled at 1100 RPM at 10-11" vacuum. After installing Rhoades lifters, I had it idling smoother at 800 RPM and 13" vacuum. I'm running a stock 340 with the MP .484/284 cam, stock converter, and 3.91 gear, Holley spread bore Mechanical secondaries and it doesn't bog off the line...

I put them in a 318 with 9.2 compression, stock 340 cam, 360 heads, 4 bbl, dual exhaust and it idled at 22.5" vacuum and got just under 18 MPG highway. I drove it over 300k miles with a set of Rhoades lifters in there.... They last and Rhoades stands behind them.

I got a new one with a pin hole where it didn't machine, back in the 80's. I called Rhoades and described the defect and they sent me one without even asking for the old one back.


They work. Some people don't think that they do, but if you ask people who have used them, they work...


Here's a link to them at Summit Racing:

http://www.summitracing.com/search?S...rhoades 2018
Click to expand...
 
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