burnt pistons....what happened? picture included.

jfholm · Post by **jfholm** » Wed Sep 03, 2008 2:15 pm

If the damage happened while using the NOS it could also be related to the NOS delivery system. That can really wreak havoc. We had one that ran low on gas part way through the run and torched all the pistons. Check your NOS system if damage happened while using it.

John

Rommel Racing · Post by **Rommel Racing** » Wed Sep 03, 2008 3:54 pm

Are you guys just screwing with me?

Did you read this thread? Where did you come up with the idea my "friend" was using nitrous.

Sorry for the rant,I just don't get it.

gimmemud · Post by **gimmemud** » Wed Sep 03, 2008 3:57 pm

I think your original assesment is a good one, problem with the front carb, most likley too rich, from the looks of the tops of the pistons, what do the others look like?

jfholm · Post by **jfholm** » Wed Sep 03, 2008 5:12 pm

Rommel Racing wrote:Are you guys just screwing with me?

Did you read this thread? Where did you come up with the idea my "friend" was using nitrous.

Sorry for the rant,I just don't get it.

In your very first post you said "any suggestion would be appreciated" So to cover every conceivable possibility to "HELP" you that is why you got all of these answers. No one is screwing with you, just trying to help. Sorry you are so darn sensitive. I guess I will just skip suggesting you check your fuel distribution as it is just the front cylinders that have gone bad the the rear are ok. I won't mention the possibility that if it is a roots blower it may be screwing the mixture rearward. My cousin wrenchs on a top fueler and I know they have messed with blower placement forward and back for a long time. But, I don't want you to be mad. I will say I would pay attention to Ron C. I think he does know what he is talking about. Thanks, Ron. I appreciate the pointers you have given me.
John

af2 · Post by **af2** » Wed Sep 03, 2008 5:51 pm

John, I feel the Nitrous part got him fizzled as would me.
You are correct on the Roots pushing everyting to the rear. I would look there IF this isn't a new problem.
Otherwise the pictures look like oil on my screen.

jfholm · Post by **jfholm** » Wed Sep 03, 2008 6:55 pm

Af2
You are right about looking awfully oily. If we knew a little more history. I had just read a previous post and had seen nitous mentioned and did not go back to the first. I have noticed your posts before and appreciate your knowledge and kind replies. Thanks

John

Rommel Racing · Post by **Rommel Racing** » Wed Sep 03, 2008 7:44 pm

jfholm wrote:
Rommel Racing wrote:Are you guys just screwing with me?

Did you read this thread? Where did you come up with the idea my "friend" was using nitrous.

Sorry for the rant,I just don't get it.
In your very first post you said "any suggestion would be appreciated" So to cover every conceivable possibility to "HELP" you that is why you got all of these answers. No one is screwing with you, just trying to help. Sorry you are so darn sensitive. I guess I will just skip suggesting you check your fuel distribution as it is just the front cylinders that have gone bad the the rear are ok. I won't mention the possibility that if it is a roots blower it may be screwing the mixture rearward. My cousin wrenchs on a top fueler and I know they have messed with blower placement forward and back for a long time. But, I don't want you to be mad. I will say I would pay attention to Ron C. I think he does know what he is talking about. Thanks, Ron. I appreciate the pointers you have given me.
John

John,it's all good

the nitrous thing did set me off a little. I'm sorry

It's just that I've seen so many threads go sideways because people post with out reading the whole thread.

p.s. I really do appreciate this post about the fuel distribution.

jfholm · Post by **jfholm** » Wed Sep 03, 2008 9:11 pm

Thanks for you kind post. I know how frustrating it can be chasing gremlins. Especially when you have tried your best. Has this engine run with the blower successfully in the past? Is this a new problem? The one thing I think I see in the picture is scoring on the cylinder. Are there little scratches going up and down on the cylinder wall or is it an illusion of the photo?
John

turbo camino · Post by **turbo camino** » Thu Sep 04, 2008 6:15 am

Any way to know if the ring end gap was lined up under the valve notch on the ones that failed?

AA Performance · Post by **AA Performance** » Thu Sep 04, 2008 9:38 am

The roots blower throws more air to the front which in turn makes the front cylinders leaner, hence that is why you usually run more fuel in the front cylinders & that is why the bigger blowers are usually set back so as to get more even air distribution with out running so much stagger in the jetting or nozzles as in blown injected alcohol engines. The bigger the blower ,the worse the problem gets.

Ron C. · Post by **Ron C.** » Thu Sep 04, 2008 12:16 pm

mmmitch588 wrote:The roots blower throws more air to the front which in turn makes the front cylinders leaner, hence that is why you usually run more fuel in the front cylinders & that is why the bigger blowers are usually set back so as to get more even air distribution with out running so much stagger in the jetting or nozzles as in blown injected alcohol engines. The bigger the blower ,the worse the problem gets.

Substitute the words "more air" with the words "more fuel" and I'll agree with you. It screws the fuel forward, hence "set back blowers".

Blessings........Ron.

AA Performance · Post by **AA Performance** » Fri Sep 05, 2008 6:28 am

Ron C. wrote:
mmmitch588 wrote:The roots blower throws more air to the front which in turn makes the front cylinders leaner, hence that is why you usually run more fuel in the front cylinders & that is why the bigger blowers are usually set back so as to get more even air distribution with out running so much stagger in the jetting or nozzles as in blown injected alcohol engines. The bigger the blower ,the worse the problem gets.
Substitute the words "more air" with the words "more fuel" and I'll agree with you. It screws the fuel forward, hence "set back blowers".

Blessings........Ron.

Must disagree with you Ron. Why are our port nozzles so much bigger at the front cylinders.If the blower was pushing more fuel to the front then we would have smaller port nozzles at the front.A blower pushes air, its simple, and a roots blower with helix rotors pushes air to the front.

us7race · Post by **us7race** » Fri Sep 05, 2008 8:02 am

My friends blown 540 has 2 port nozzles on #1 and #2 the rest have only 1.. It is a Kebelco 14-71 Hi-Helix Superman Blower

AA Performance · Post by **AA Performance** » Fri Sep 05, 2008 9:34 am

us7race wrote:My friends blown 540 has 2 port nozzles on #1 and #2 the rest have only 1.. It is a Kebelco 14-71 Hi-Helix Superman Blower

Like I said Ron,pumps more air to the front so you need to throw more fuel in to avoid a lean condition.The further back you set the blower,the more better the air distribution will get.Hope this info gives Rommel racing some where to look for the problem he has in front of him.Your problem as I see it is definetley detonation.

Ron C. · Post by **Ron C.** » Fri Sep 05, 2008 2:46 pm

mmmitch588 wrote:
Ron C. wrote:
mmmitch588 wrote:The roots blower throws more air to the front which in turn makes the front cylinders leaner, hence that is why you usually run more fuel in the front cylinders & that is why the bigger blowers are usually set back so as to get more even air distribution with out running so much stagger in the jetting or nozzles as in blown injected alcohol engines. The bigger the blower ,the worse the problem gets.
Substitute the words "more air" with the words "more fuel" and I'll agree with you. It screws the fuel forward, hence "set back blowers".

Blessings........Ron.
Must disagree with you Ron. Why are our port nozzles so much bigger at the front cylinders.If the blower was pushing more fuel to the front then we would have smaller port nozzles at the front.A blower pushes air, its simple, and a roots blower with helix rotors pushes air to the front.

Don't know your name to address this to, but you are right in the terminology for the application you stated. I actually had a much longer discussion typed out...with exceptions, and as I hit the key board button the site connection went blank and lost it, so I was in a hurry and typed out my incomplete statement. As I walked away from the key board I thought, that will be challenged. When my brain heard "setback blowers" it immediately went into blown nitro mode which air is not there issue, fuel volume distribution is, which is completly unrelated to this thread.

The Roots type blowers do need more fuel volume to the front cylinders and if you run a high helix it's even worse. My son's roots blown alcohol motor, we do have larger nozzels in the front cylinders also. On my centrifugal blower application that's not an issue but it still does have favorit cylinders.
If you notice in Top Fuel type engines you'll see added fuel nozzels at the manifold back to help in screwing fuel forward. And fortunately we never got into hat nozzels.

Boy, did this get off track from the original question. And I certainly contributed to that......sorry for the journey.

Blessings.......Ron.