Paduka Thread Closed Quick !

[leathermang]

Must be a story behind this.... was there evidence of ' tomfoolery' ....like spoofing or something ?

[acy76]

I would hope so. Otherwise it would have been a good opportunity for someone to learn about the differences between turbocharged diesel and turbocharged gasoline engines. His question is completely valid when referencing the latter variety.

[leathermang]

I was figuring it was a joke because what are the chances of finding lower compression annular ring oil cooled pistons for our cars ?
I was going to ask him HOW MUCH lower compression... to see if he would fall into the trap of getting low enough that it would not run ... but of course it would not let me play... I mean post....

[Brian Carlton]

Originally Posted by leathermang

Must be a story behind this.... was there evidence of ' tomfoolery' ....like spoofing or something ?

Can somebody kindly explain what's going on here?

What's wrong with asking about lower compression pistons??

I'm just going to ask the boss.

[Hatterasguy]

I have heard of them doing this to diesels. Lower compression lets you shove tons of boost into the engine. Combined with a big intercooler you can make big hp numbers. The IP would need to be changed though.

I have thought of getting a 3.5L bottom end and putting 3L connecting rods in it. Then you could push some serious boost pressure through that motor.

[Brian Carlton]

How much lower you talking about??

How are you going to start them?

[Hatterasguy]

I don't have the exact numbers I was just thinking. A car with an engine like that would only have to start on 70 degree and warmer days. Glow it twice and have a strong battery she will fire.

[Brian Carlton]

Originally Posted by Hatterasguy

I don't have the exact numbers I was just thinking. A car with an engine like that would only have to start on 70 degree and warmer days. Glow it twice and have a strong battery she will fire.

She'd be a downright pleasure at 20°F. You'd have to glow it with an acetelyne torch.

[coldwar]

Lower compression is the norm for "competition" Diesel engines- a la tractor pulls. This way the compression is built outside the engine via the turbos instead of making the engine itself work so hard to provide high compression. This is why the competition engines run so rough and pound out light blue smoke at idle- they are extremely mis-firing, until the boost gets built up. Then watch out- you get screamin' 6000 RPMs, a dense black plume with orange flame coming out the stacks, and they keep it all together with water injection.

[leathermang]

"until the boost gets built up."

Exactly... and there is some ' lower compression ratio' at which between the glowing and the turbo kicking it where it won't fire. Meaning you can't even get it TO the rpms at which the turbo will kick in.

My guess is that Paduka is a dealer in lower compression pistons and came on here for advertising purposes... and got caught... but that is just a guess.. wish someone with the real story would tell us what happened...

Maybe they were just concerned for Brian's blood pressure..... he seemed to get excited about the idea...

[Brian Carlton]

Originally Posted by leathermang

Maybe they were just concerned for Brian's blood pressure..... he seemed to get excited about the idea...

Excited.............me??..................hardly.

But I was interested on how the thread became locked. After inquiry, it seems that it was not of the moderator's doing. Apparently the initiator of the thread can lock it.

Who knows what he was thinking???

[leathermang]

"Apparently the initiator of the thread can lock it."

I did not know that.... What a great new tool to keep out muddy water.

Ok , after looking at it ... I can see "Close this thread after you submit your message. ",, but how did he close the thread AFTER you posted Brian ?
He did not post again after you posted....

[Brian Carlton]

I never tried it and don't know the mechanism to do it.

Just relaying the message from the boss.

[Old300D]

I can see reducing the compression on an extremely boosted tractor engine, as you may not have enough intercooling to stay within the thermal limits of the engine. I understand some run hundreds of psi boost.

It seems foolish to reduce the compression on a diesel, as there is no chance of predetonation on a diesel. If you intend to run crazy boost, just intercool it to ensure your exhaust temperature stays within limits. Gassers, on the other hand, benefit greatly with reduced compression, as it gives all sorts of safely margin to increase boost, avoiding predetonation. My factory Nissan engine, an L28ET, came with 7.4:1 static compression ratio. Lots of people run 20+ psi boost (intercooled) to get 400 hp on unmodified engines.

[boneheaddoctor]

Originally Posted by Old300D

I can see reducing the compression on an extremely boosted tractor engine, as you may not have enough intercooling to stay within the thermal limits of the engine. I understand some run hundreds of psi boost.

It seems foolish to reduce the compression on a diesel, as there is no chance of predetonation on a diesel. If you intend to run crazy boost, just intercool it to ensure your exhaust temperature stays within limits. Gassers, on the other hand, benefit greatly with reduced compression, as it gives all sorts of safely margin to increase boost, avoiding predetonation. My factory Nissan engine, an L28ET, came with 7.4:1 static compression ratio. Lots of people run 20+ psi boost (intercooled) to get 400 hp on unmodified engines.

Its a common thing to do on GM 6.5 diesels that are built for Marine and high performance use.....they replace 20-1 with 18-1 pistons...That allows more boost and conversely fuel to be run without over stressing engine components.

Peninsular Diesel (spelling) had these doing 300hp and 500hp with no reduction inreliability or reduction in engine life..........for boats and high performance and towing use....