Nice work! Don Garlits always said "run um loose with lots of oil pressure". LOL
Low buck 360 build
- Thread starter Mean416
- Start date
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So, the cheap rebuilder pistons had a cheap set of rebuilder rings installed. I removed them to clean everything up. I noticed that the rings that say " top" were on the 2nd ring groove. Top pointing up. These rings have an inner bevel. The rings in the top groove had no bevel. I have no idea the manufacturer of these rings so no real documentation. Should I reinstall the same as it was?
Correct. "TOP" just means that side of the ring faces UP.
Rat Bastid
Dunamis Metron
It’s unusual for the top ring to not have a bevel and the second ring to have one. It’s usually the other way around but I don’t use cheap rings so that may be correct.
For the record, I don't usually use cheap things either. But this is what came with the engine so...I'll take pics tomorrow and try to get an Opinion of how it goes together. Whoever installed the rings before were very consistent. The rings with the bevel were all in the second groove.
I've used cheapass rings and I can tell you they come every way under the sun. You know, even decent rings aren't really ALL that expensive. hint hint.
Hahaha hint taken. The 418 under the bench got the message
This however is the $1500 engine that will make 300-ish hp and get the dart sold.
Rat Bastid
Dunamis Metron
The picture is a bit fuzzy but that ring thaT says top on it looks more like a second ring to me. No bevel almost always means a second ring. But, there are strange things and this may be one of them. Who made the rings?
I was trying to show the bevel. It has the bevel on the inside lower edge. I have no idea who the manufacturer is. I'm sure it came in a low buck rebuild kit. It came with the box of parts with the engine I purchased.
Maybe this pic is a bit clearer. Ring in upper position was installed in the top groove and has no bevel. The ring with the bevel is on the bottom, the bevel is on the inside edge. This is showing opposite the side marked "top".
Here's a pic showing how they were installed when I received the items.
When I first got these I saw this and thought it was incorrectly installed but I wonder, because all 8 were like this so it's like the guy was following instructions.
Here's a pic showing how they were installed when I received the items.
When I first got these I saw this and thought it was incorrectly installed but I wonder, because all 8 were like this so it's like the guy was following instructions.
Rat Bastid
Dunamis Metron
Ahhh, I couldn’t see that. If it has the bevel that faces down with the word top on that indeed is a second ring.
That bevel is critical, especially for a top ring because that’s what gets the rings to seal. Combustion pressure moves down the side of the piston and hits the top ring. It then moves across the ring to that bevel where it gets behind the ring and forces into the cylinder wall, making it seal.
Without that bevel to get the gas pressure in behind the ring retards ring seal.
Thats what gas ported pistons and rings do. They get combustion pressure behind the ring more directly and therefore quicker and it makes more power.
Plus, you can reduce the radial tension of the ring by a bunch and save on a ton of friction as the ring is just along for the ride on the other strokes.
So I think the ring with the bevel on the top is a top ring and the other is a second.
Rat Bastid
Dunamis Metron
Ok, now I’m confused again. In this picture that second ring has the bevel facing down. And that ring, the way it’s installed in the picture says TOP on it and the TOP is up?
If that’s what it is that certainly must be the way they go because you wouldn’t want that ring in the top groove.
I‘m having a hard time getting my head around why no bevel for the top ring. That’s crazy IMO.
It's just a cheap set of rings. So I actually found this quote on motor trend (not that they don't publish garbage all the time but it's at least something)
"Usually, the rings are bevel-cut to promote twisting. The top ring is often beveled on its top inside edge, which causes positive twist. That pushes the lower inside edge against the ring groove and creates an oil seal, while also allowing cylinder pressure to get behind the ring. The bevel of the second ring is machined in the lower inside edge to create negative twist and press the lower outside edge of the ring face against the cylinder wall for oil-scraping"
So given only one ring has a bevel, and it's on the bottom edge, I am keeping that ring in the second groove.
Other general updates from today's mad rush....
Goal today was to get this reciprocating assembly completed.
I decided to add a little bit of ring gap. Just in case I end up keeping it and decide, you know, a little bit of ring gap on a low compression engine could be useful
So with the rings gapped, I assembled the rings in the pistons. Gave the bores one last super cleaning before popping the pistons home.
Squeaky clean...
Now pistons are installed...
Couple shots of the completed reciprocating assembly...
It spins really smoothly too. Taking right at 25 ft lbs to turn over. Pretty good for a fresh street engine.
That's all I got for today. Hoping to get the top end buttoned up tomorrow.
Goal today was to get this reciprocating assembly completed.
I decided to add a little bit of ring gap. Just in case I end up keeping it and decide, you know, a little bit of ring gap on a low compression engine could be useful
So with the rings gapped, I assembled the rings in the pistons. Gave the bores one last super cleaning before popping the pistons home.
Squeaky clean...
Now pistons are installed...
Couple shots of the completed reciprocating assembly...
It spins really smoothly too. Taking right at 25 ft lbs to turn over. Pretty good for a fresh street engine.
That's all I got for today. Hoping to get the top end buttoned up tomorrow.
Minor update. Been a busy week so far. Just did a last clean up of the deck surfaces on the heads, dropped the head gaskets on, and installed the heads. Nothing huge but hey it's a little bit of progress. Hopefully the top end can get completed this week/weekend. Heck I might even be able to get the intake on.
As a side project, I've been working on converting my engine stand into a test run stand. Maybe I'll post up how that comes along, if there's any interest.
As a side project, I've been working on converting my engine stand into a test run stand. Maybe I'll post up how that comes along, if there's any interest.
Sure! Why not. There is a older thread around here on some home built efforts. Post it up!
I think mine is going to be fairly unique. Waiting on a few parts to come in then I'll start CADing up the various brackets etc.
Tsully
Well-Known Member
Are you sure weren’t just busy trying to sort through all the 22 pages of “The highest flowing SBM heads” post!!
Are you sure weren’t just busy trying to sort through all the 22 pages of “The highest flowing SBM heads” post!!
Hahaha no way. I haven't read more than a third of that monster. Too many people getting panties in a wad for my taste. However last couple days it seems to have steered in the direction of actually talking about heads which is all I wanted in the first place.
A body just posted 2 cents & worthy info.
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