American Speed engines - piston rings

[BobM]

Spoke to Gail at American speed last night to discuss ordering an engine. He mentioned that the prices have gone up a bit as Ted has asked if engines supplied for Ultimas can be built with some kind of gap-less piston rings. Anyone know more about reasons for this?

Bob

[Stig]

Dunno why, other than reducing the oil consumption and raising the compression a tad?

[Stig]

Have spoken to the Ted and it's simply down to personal preference of his. After all, if you're using a ring to seal the gas into the commbustion chamber, it seems to be a bit daft to have a ring with a gap!
Gail obviously seems to agree which is why he's gone over to the zero gap rings (it wasn't an instruction, more of a chat).

Anyway, it's nothing sinister and the price hike should be fairly negligable.

[BobM]

Thanks Stig - the price hike is $150 which I'm not particularly worried about. I just wondered if there had been any issues with the other rings ... I accept your points about gapless rings being theoretically better but haven't heard of them being used elsewhere. I presumed also that we've been using rings with gaps for a few years now for some reason!

[jschwartz]

Gap is required for expansion reasons. Gapless rings still have a gap, but are a 2 piece ring with one ring oriented differently to cover the gap of the other in the same groove. So called Gapless rings are worth 5-10 hp on a 500 hp engine, no difference in oil consumption.
jeff

[arthurr]

I am currently having a problem with an AS engine which is burning oil. It seems the rings have not seated after 300 miles. I spoke with Gail about this and he thinks it may be due to a gas soaking event during break in that is causing the problem. Engine runs like bear but the emmissons are off the scale. Anyone have a similar problem and a solution other than reringing the motor?

[steve_D]

Post this on chevytalk
The guys there may be able to help.
My thoughts are that 300 miles is still early days for a chevy engine.
All the breakin advice I received was to push it hard and try to load the engine. They also acepted that in a light car that would not be easy.
There may also be some chevy 'trick' to overcoming this potential glazing of the bores.
If 'grumpyvette' or 'stevestreeter' tell you what to do, believe them, as there are not many who know more about the SBC.
Good luck

Steve

>> Edited by steve_D on Tuesday 5th October 23:16

>> Edited by steve_D on Tuesday 5th October 23:17

[BogBeast]

I have heard that zero gap rings are harder to crank when hot.

Met the owner of a well sorted sport (I think he used to run the old owners club...) IIRC he had to fit a 2nd battery to cope..

[bigmack]

steve_D said:

If 'grumpyvette' or 'stevestreeter' tell you what to do, believe them, as there are not many who know more about the SBC. Good luck Steve

Isn't that the truth Steve... Those guys are sharp.
Cheers!
-Mack

[G Man]

Gapless ring have been in my engine for 2 years.

The give you 600 bhp + easy .....

Serious they are alright ...

G MAN

[Boosted Ls1]

I've use Total Seal gapless rings before now and have them for the LS1. They are reputed to pull more vacuum due to better cylinder sealing so it's maybe a good idea to fit a restricter in the pcv line as you could find your engine sucking excess oil down the valve guides.

Boosted

[ultimacz]

I have done a lot of research on this topic, because my AS engine burnt oil from day one. First I was told that the rings need time to settle and that I should use only mineral oil for the first 5000 miles... All nonsense, in my mind. Burnt 3-5 litres of (mineral) oil per 1000km even after 6000 miles, depending on how hard the car was driven. IMO main reason for this is that the ring gaps are pretty big because the Ultima engines tend to run hot. From the manufacturer´s point of view it is better if the engine burns more oil than to risk that the motor is severly damaged if the gaps are small and the rings butt. Other (minor) reason are problems with valve stem seals which can be damaged if the motor is running too hot.

Now I have replaced the rings by Total seal gapless. Also new special valve stem seals for higher temperatures. Oil consumption is only half, despite that I use only full synthetic oil from day one. Oil also looks much better, is no longer that black and dirty after a few miles as it was before. Don´t know who else has this experience but I always found oil drops/marks on the rear end of the car and this has gone completely with the gapless rings. Engine starting is also no issue, only when I drive on the track and motor is very hot it would not start. Letting it cool down for 1 minute and it will start again.

Don´t believe if somebody tells you that a SB should use only 1 litre per 1000km or less. These pre-historic things are oil-burners by design and if the consumption is not exceeding 3 litres I would not be concerned personally.

[gdr]

3-5 litres per 1000 km! Sounds a bit severe. Mine seems to use about 1 litre per 1000 km although not sure if being burnt or falling out. Less in cruise, more on track but averages out. Engine always a bit oily here and there although no drips on garage floor. Mine was not built by AS and uses C&A rings, not zero gap. Bit tight on restart if you stall it hot, but OK after 30 seconds. Any other experiences?

[ultimacz]

Congratulations, gdr! 1 litre is something I can only dream of....

Maybe there is still something wrong with our engines but the gapless rings reduced the oil consumption at least to around 2 litres, which I can live with. (don´t need to carry any longer 5 bottles of oil with me on every longer trip)

We have 4 Ultimas over here, all with similar engines only differ a bit in power output (450 to 550 HP). From what I know all of them consume a lot of oil. I am sure that all of them were run in differently and also the owners service them differently and use different oils, and still the result is about the same...

Still think it has something to do with the engine design. My new 5´series BMW used half a litre for the first 25.000 km of quite hard driving - wow, what an engine!!

[bigmack]

Funny. I've not had any oil consumption problems with my engine. I only have 1000 miles on my engine though. I'm still running mineral oil. When I had cooling issues(due to improper hose sizes on my stack manifold) my rear cylinders were a bit oily after the first 50-100miles and I went through about a quart before 100miles. Since breaking in the motor, and redesigning the cooling to provide more cooling to the rear two cylinders, things are much better. I've not had to add any oil. Then again, I may not be running my engine as hard as some others on here. Just city driving with occasional sprints to 100mph at 7k rpm.
Are you guys running a pcv valve, vaccum pump, or vaccum kit to the headers? This is always a good idea for high performance/race engines that see a lot of 5500rpm+ revs in their lifetime. I think it should be standard on the engines we are using, but that's just my opinion.
Cheers!
-Mack

[ultimacz]

we are using only breathers on both valve covers, as is standard Ultima design. From what I know the PCV valve sucks the oil mist out of the covers and back into the motor to burn it (reduces emissions of crankcase gases). I did not understand think that it can influence oil consumption in any way?

[canam-phil]

Should I be worried? My non-AS engine (525BHP 383) is not using or dropping oil. Since changing oil (long blast of 900 miles and 200 miles since including a trackday) did not drop the oil level at all. Still clean as the day it went in at 500 miles. Now up to near 2000 miles. Even before the oil change at 500 miles it did not use any from new.

One thing comes to mind is what level oil we are running in the sump when an accusump is used. Its been discussed before. Oil splash from high oil levels will play a part I would think.

My engine does not have the gapless rings.

And another thing, it never suffers from a problem starting whether cold or hot.

Another observation. Some SBC engines I have seen are running so rich that they load the oil with unburnt fuel.

I would be interested to hear what the compression pressures on the AS engine with high oil consumption are?

[Boosted Ls1]

ultimacz said:

we are using only breathers on both valve covers, as is standard Ultima design. From what I know the PCV valve sucks the oil mist out of the covers and back into the motor to burn it (reduces emissions of crankcase gases). I did not understand think that it can influence oil consumption in any way?

If the pcv system flows to freely then more oil will pass into the inlet. Also, if you use a gapless ring pack there will be greater vacuum applied to the valve guides when you lift off the throttle and oil will be drawn down the guides. There should be a restrictor in the circuit, limiting the amount of air drawn into the rocker cover if you are using a pcv system.

Boosted.

[htny]

Phil - if you don't mind me asking, who built your motor, and is it a Gen 1 chevy style unit?

[bigmack]

From the sounds of it, there are only two possible scenarios. Oil is either leaking out of the engine somewhere or it is being burnt up in the combustion chamber from oil blow-by and travels out the exhaust. A gapless ring will help prevent some oil blow-by. A vacuum pump, if it could be fit to our setup, would really help with this and give a little extra hp (20-30) as well. Bloody expensive little guys though.
Cheers!
-Mack