Hey guys!

[s10rodder]

First off, what\'s up everybody? I haven\'t been around here much lately, but I have been lurking here and there. Good to see the usual guys helping out as well as some new guys hanging around.



So, the main reason for my post is just to say what\'s up and give an update, but also, I have an extra set of brand new 3\" DJM steel lowering blocks up for grabs on ebay if anyone is interested. <hr><img src="images/forum/ebaylink.gif"> I saw this on eBay motors: DJM 3\" blocks (http://cgi.ebay.com/ebaymotors/ws/eBayISAPI.dll?ViewItem&item=8017757489)<hr>



So, the latest news with my engine is that my builder got it torn back down after ruling out an intake manifold leak. What he found was pooled gas sitting on top of the valves at the end of the head runners on one bank. It was pooled in the side that is fed by the lower side of the dual plane intake. He said all 4 pistons in that bank were completely clean, like they had just come out of the box. One of the pistons in the other bank was also like that, with the remaining 3 having a fairly normal looking dry black carbon deposit on them.



The truck had been running extremely rich at idle and mid throttle. I had been working on figuring it out before I brought it back to the shop. I could close the idle screws to the point the engine would almost stall and it still smelled rich at idle. When we had it on the engine dyno, WOT A/F was almost perfect, so obviously, if I\'d take it for a spin around the block and hammer on it, it would clean up for a little while.



Here\'s how my builder explained the clean pistons: The idle was so rich and so much fuel was being dumped into the cylinders that it was \"washing\" the pistons. It also was washing the oil off the cylinder walls, keeping the rings from sealing completely, thus the oil fouling and black smoke.



Make sense to everyone? The shop is now doing a hone and re-ring before reassembly. Then we will get the carb issues worked out on the chassis dyno with all his fancy exhaust gas testing equipment before the truck comes back home.

[wild85]

Hey Andy



Sounds like you are gettng somewhere, that is good to hear. Not sure if you heard, but my dime is smashed all to hell. Was taking it to be parked for the winter, and got rear ended by a 71 montecarlo.

[jeremytkoontz]

I dunno, I\'ve torn into a lot of engines and the only thing I\'ve ever seen that \"cleans\" a piston is coolant... just my two cents though

[s10rodder]

damn dude, that sucks... are you getting insurance money? Going to rebuild?

[Knanthrup]

On 2005-12-01 13:58, jeremytkoontz wrote:

I dunno, I\'ve torn into a lot of engines and the only thing I\'ve ever seen that \"cleans\" a piston is coolant... just my two cents though







Yeah I\'m with you on this one. I can\'t say for sure because I am not a professional engine builder to have authority, but I have not heard of gas doing that. If you were running rich it should have carboned or blackened up the back side of the valves as well as the inside of the cylinders (head and piston top). If you were getting enough gas in there to clean up like that, it had to have been POURING down the intake (like a stuck float) and none of those clean cylinders should have been running at the time... did you have multiple dead cylinders under idle? And even if they were dead from enough gas running in, the heat from the engine block still should have burnt the gas in the dead cylinder and carboned it up. I don\'t know, it just doesn\'t sound right to me. Steam cleaned pistons have always meant water in the cylinder from my experience. I am no expert though so I do intend to stand above a real engine builder\'s opinion. just my 2c



Andy, regardless I really do hope to see your truck get back together in good running fashion. I know it\'s been a long road for you trying to get this new combo worked out so I wish you the best of luck.

[s10rodder]

If you were getting enough gas in there to clean up like that, it had to have been POURING down the intake (like a stuck float) and none of those clean cylinders should have been running at the time... did you have multiple dead cylinders under idle? And even if they were dead from enough gas running in, the heat from the engine block still should have burnt the gas in the dead cylinder and carboned it up.



well, there obviously was A TON of extra fuel coming out of the carb, since my builder said it was pooled in the runners of the heads sitting on top of the valves. He said at first he thought it was coolant, but he is sure it\'s gas. Said there was enough of it to pour it out of the heads. It had been idling worse and worse, where it was barely running by the time it made it back to the shop.



He said his thoughts are that the rest of the pistons would have cleaned up like that too if I had run it long enough. Said it was good I brought it in as soon as I did cause I could\'ve really messed things up if I had kept driving it.



Said luckily, there was no damage to the cylinder walls or piston skirts.

[grimpuppy]

If there was that much fuel running into the engine the oil should have had a lot of fuel mixed with it. Like you builder said, good thing you brought it in when you did. You would have lost a bearing really quick with all the fuel in the crankcase.

[oncearacer52]

Engine builders never admit fault. Keep that in mind here. Hard to say from 600 miles away but, there are some things that don\'t add up.

[Scotty_S-15]

Hey Andy, good to see you\'re still with us. And, good to see there is some progress with the motor.

....... I could see what your engine guy is saying about the \"clean\" pistons. The guys who are doubting that, maybe don\'t know that your engine didn\'t run long enough http://www.s10v8.com/images/smilies/icon_frown.gif for them to get very carboned up in the first place. The thing that puzzles me, is that the engine guy said the fuel was puddled on the bank fed by the lower runners.... But don\'t all dual planes split the low/high runners? That is, high, low, low, high, &amp; vs. versa the other bank. Whatever.

......... And I\'ll ditto what Grim said about the gas-in-oil thing. That\'s why I\'m always preaching to change the oil if it\'s been flooded badly. Also, I\'ve been known to preach that if an engine has flooded, and doesn\'t want to start, to pull the plugs, squirt in oil (to benefit the walls &amp; rings), crank it around to blow out excess oil, put the plugs back in and start \'er up.

........... Was that a brand new carb, Andy? Or the one you had? Because I\'m thinking that if it was a new carb, maybe there is something internally wrong... and if so, I wouldn\'t want to be sorting it out on my newly re-ringed engine. If it was your tried and proven carb, it might be worth a peek inside to make sure all is OK, and double check your pressure gauge/regulator, etc.

............ Point is, I wouldn\'t be too quick to stick that same carb back on, especially if it was new and unproven. \"NEW\" is usually good. But \"PROVEN\" is better. Of course, new AND proven is the bestest. http://www.s10v8.com/images/smilies/icon_biggrin.gif http://www.s10v8.com/images/smilies/icon_wink.gif

[Scotty_S-15]

I thought this whole gas-in-oil scenario sounded familiar.... here\'s a quote from a different, but recent thread:





On 2005-11-16 21:52, anonymous wrote:..........................case in point: I\'ve got an old, really old, POS 350 Chevy boom truck-work van. I seldom see it, (I\'d prefer not tohttp://www.s10v8.com/images/smilies/icon_razz.gif) my guys use it once in a while. I recently went to the job, it was smoking badly, hitting on 7 cylinders. I changed the plugs, but still smoked badly. So then I changed the oil, and the smoking stopped, just as I had hoped. Now it runs like new. The oil was so fouled with gas from the missing cylinder, that it burned oil like crazy. But it\'s still a POS... soon to see the crusher.... http://www.s10v8.com/images/smilies/icon_eek.gif http://www.s10v8.com/images/smilies/icon_wink.gif



........... So Andy, maybe you just needed a new carb, and a trip to Jiffy Lube! http://www.s10v8.com/images/smilies/icon_razz.gif But seriously, it\'s probably best that the engine got torn down, the gas may have done permanent damage to the rings &amp; seating process. Enough gas in the combustion chamber, washing down the walls, then diluting the oil, is like running the engine without any oil at all, at least for the rings.

[Knanthrup]

Andy,

please don\'t take what I said in a serious fashion of disagreement. Like I said I have limited experience on that sort of problem.

Once again im just glad to hear you guys have gotten it apart and are fixing the problem. hope you get her running again soon.



Now time to get that carb tuned!



You would think she should put down some better dyno numbers with the carb tuned correctly don\'t you think? We can hope anyways http://www.s10v8.com/images/smilies/icon_smile.gif

[s10rodder]

Well, my true feelings are, that the builder is a good, honest guy. I really think he is being straight up with me and he assured me ahead of time not to worry, that he would take full responsibility if he was at fault, even going as far as saying \"I\'m one of the most honest guys in the business.\" I know, anybody can say that, but I really do believe him. He\'s built up quite a reputation with his shop and has been in business for a LONG time. He even wanted me to come down and look at the pistons, but the shop is about an hour away and I really do trust this guy.



It does make sense to me for a couple reasons, first, the exhaust would always clean up after I would run it hard up and down the road a few times. The longer I\'d let it idle or cruise, the worse it would smoke. Also, I let it idle for a while once while trying to tune out the smoke, so I figured it was a good idea to change the oil since it had been running rich at idle so long. When I changed it, it STUNK like gas, LOTS of gas in the oil. You could smell gas just by pulling out a breather and taking a whiff, even after I changed the oil.



Anyway, I am planning on trying a different carb, at least at first, and I will keep you all updated.

[spacecadet]

Since your motor man determined that thier is too much fuel, I gues the next thing to do is replace the carb. Unless you can bring the carb to a rebuilder who can flow test the carb before it getts installed.



Gas is very bad for the cylinder walls, as you already know it can smoke the rings. Definitley keep up on the oil changes once you get it going again.



Space.

[oncearacer52]

If it turns out to be your mech. fuel pump your engine builder is not honest.

[s10rodder]

fuel pressure at the carb inlet was 8-9 psi at idle. I mentioned it to him and he agreed it seemed a little high, but not something that would\'ve caused the severe overfueling.



Maybe I\'m not following... the fuel pump could\'ve caused the problem?

[wild85]

No rodder, i am done, parting it out.

[oncearacer52]

Blown diaphram in fuel pump will put gas in oil (if it is a mechanical pump) but, it won\'t put gas in your intake runners.

Also as far as your carb goes. I think one or both of your bowls would have to be overflowing quite a bit to leave gas on top of your intake valve. If it is a carb problem it could be the metering plate. This carb wouldn\'t have been gone over by a carb guy? If so was it for a round tracker? If so you will have to change those metering plates because there will be some very big holes drilled in there.

I don\'t know your engine builder and he may be the best around but, it seems all of them start hollering washed out rings when a new engine turns out to be crap. I\'d like to ask everybody on here how many cars do you thing were started and ruined today by pouring gas down the carb?????? I have washed out rings before but it took a whole lot of alcohol to do it. Then after fixing the problem it took 6 or 7 runs for them to reseat.

[oncearacer52]

By the way what is the duration and lift on your cam?

[s10rodder]

the weird thing about the carb is that it had been running OK on my previous combo. I had the bottom end done with a stroker kit last year by this guy and used the same carb. It was right around 12.5-13:1 at WOT, so jetting should\'ve been close enough. It was just the idle. I had ordered an idle feed restrictor kit from demon that never came in at my local shop. I was going to try that to get the idle to lean out, since I couldn\'t even lean out the idle with the mixture screws.



The cam is a solid roller, 242/248 @ .050, .580\" something lift. 110 LSA

[downtoearth]

Any new pics of the truck?

[oncearacer52]

I had a 750 Demon that was a ton of trouble. heck part of the holes were never drilled in the metering plates. That idle restrictor kit you are talking about is a much needed part for the Demon. Once I semi remanufactured (lol) that carb it was awesome.

I thought that the cam may have been causing the rich idle condition but, I doubt it now that I know the duration figures.

Good luck. I\'m sure you will get it.



ps I would call Demon again about that kit. When I got mine they were free because they screwed up so bad.