Baffled by apparent reversion issues with Lightning headers and mild cam
 

I am running a set of Lightning's with the divorced collectors on a 489 Chevy with AFR 265's and a relatively mild hydraulic roller cam. Cam is 226*/230* with 114* LSA, .612/.596 lift. Stock Merc seawater pump, circ pump and T-stat housing.

I'm running it on a test stand. I even tried putting wood blocks under the front of the stand to get it at a downward angle similar to the boat would have. Every time I shut it down and pull a header, I get a teaspoon or so of water out of the primaries.

Headers were pressure checked with air a couple months ago. Held about 18 PSI of air for several days. Engine was dyno tested, and block was pressure checked with air during assembly, so don't think it is a head gasket or intake gasket. Oil is clean, no sludge showing up under breathers or anything. Plugs look slightly wet when I pull them, however. I ran these same headers on my previous engine, and did not see any signs of reversion with that engine.

Starting to wonder if I am going to have to plumb in some type of dump valve to limit the flow of water going through the headers. Has anyone encountered this issue with the Lightnings or some other type of header?

Any chance this could be something as simple as condensation on the inside of the primaries? It's extremely humid and about 86* today. Block temp is not getting above 120* on the hose.

Yes . Don't panic . + some water vapor is a byproduct of combustion . Any steaming under the valve cover ? Take off the oil fill lid and look at it and down inside , no moisture no problem . I have a friend with an all aluminum Donavon 540 and always has a little bit foamy just under the oil fill lid .

It appears to be bone dry under the oil fill in the valve cover. No sign of milkshake of foamy oil. Dipstick looks clean. However, I did pull a couple of plugs right after shutting it down, and could see just a little bit of moisture on them. That's my main concern.

Also seeing some water condensing on the inside of the clear vinyl tubing for the breathers, but that is pretty normal. You may very well be right. ;) Thanks for the reply!

Still wondering if it might be a good idea to set up a dump valve to limit the amount of water that is going through those pipes. Seems like a lot. I think I recall and OSO'er saying that he had done this with a set of lightnings - ezstriper maybe? I'll have to do some digging.

Budman, I run Lightnings on my motors, 238/248 duration no water issues. I have 4 very small exit holes in the collector at 12,3,6,9 o'clock for water to enter the exhaust and cool the rubber coupler, with a 1inch dump on each header to dump overboard, if you do the same you will be fine! They also worked well with 258/260 duration before I detuned the motors.

It's very possible that you may be at a 'bad' collector length for exhaust wave tuning. Remember, your rubber hoses and tailpipes will add more length, which greatly changes wave tuning.

You ever drag race an open header exhaust and a 12"-14"-18" collector extension makes your car run better and a bunch faster ?

I have Pipemax on my work computer and can run it for you, but may take a day or two since I have work up my azz.

It gives best and worst pipe/tube dimensions in regards to reversion and power.

Interesting. Doesn't sound like there would be any easy fix for that one, other than a completely different header design. I may give Lightning a call today to see if they have any ideas. I realize that sometimes cracks will only open up under expansion from heat, but this is happening on both tubes for every primary pipe, which I think effectively rules out leaks in the headers.

I can take some measurements on the primary lengths and collector lengths - do you need pipe diameters too?

Were your headers set up this way from Lightning, or did you install the dumps? Are they on top of the collectors?

Re-read my 1st paragraph.

Your headers collectors + everything to end of tails = your collector length. Thus that may be fine but just the open headers with no tails on your stand may cause issues.

I'll try to run it tonight.

Later.

I ran it both ways - just open headers and also with connector hose and muffled tips. Seemed to do the same thing.

I'm also wondering if this might be a little bit that is getting sucked back on shutdown. My understanding is that this is when the risk of reversion is the highest. However, I would expect to just see the water in the one pipe that is sucking back.

Since pictures are worth a thousand words, here are a couple of shots of the engine on the cart. This is the first test when I had the silent choice diverters mocked up. When I started seeing water in the tubes, I switched back to the original divorced collectors that have an inner pipe that effectively extends the dry part of the pipe and extra 9 inches or so. No change in the water in the primaries.

http://i1224.photobucket.com/albums/...601_125653.jpg

http://i1224.photobucket.com/albums/...601_125709.jpg


And here is a picture of the water that is showing up in the tubes. Like I said, it's not a whole lot, and so far no sign of any water in the oil, but this is after just a minute or two of idling at 800 RPM:

http://i1224.photobucket.com/albums/...601_142735.jpg

Talked to Lightning, and he thinks it is reversion rather than condensation. He recommends using silicone in the joint where the inner pipe of the collector extension mates to the main collector. I will try that tonight.

He also said they don't generally recommend using any kind of muffled tips or mufflers with their headers, although he did say that it should be OK with my cam specs.

Here are a couple of pictures of the divorced collectors. As you can see, they have 4 or 5 holes in the tip about 3/8", and one in the bottom for water to come out. I was watching it run and it looks like a waterfall coming out of there. Seems like too much water to me. Might try to post a video of it running when I get my boogered up spark plug hole fixed (another story...:mad: )

I'm wondering if anyone can tell me for sure that the 5 holes go on top. Might have to call Lightning.

http://i1224.photobucket.com/albums/...602_203233.jpg

http://i1224.photobucket.com/albums/...602_203617.jpg

Thats quite a bit of water in there buddy. My tails are super short and I had a 'waterfall' in there too but as far as I know it never made it any farther than the collector getting all wet.
Either way I didn`t like it so I sealed up the water holes (slits in my case)with SIX10 and had a guy weld in a pisser just to keep the mufflers cool. 3/4" bungs inside and all water overboard.


http://33outlaw.zenfolio.com/img/s6/...84605872-3.jpg


Better safe than sorry.

What is SIX10? Thought about sealing up a couple of those holes and adding an exterior bung to the header collector to dump it overboard.

I still have my Y-pipe in there. Toying with using that to dump the excess water instead of drilling another hole through the hull.

Can't believe I'm even having to worry about this with that mild cam and Lightnings. Leave it to Budman to find yet another clusterfuq. They just seem to follow me like a stray dog.

Have you though about making the inner pipe longer?

Not really a good way to do that. Don't have the room.

To add to the problem, that silent choice is a reversion cluster waiting to happen. Looks like you have been running it straight so far, but just keep in mind issues might arise when you are idling with silent choice on...

Did jan recommend modifying your headers for "reduced water"?

Borg, I'm running it now with the straight non-SC collectors and getting the same reversion. And no, Jan (assuming the guy I talked to at Lightning) did not recommend modifying them. He did recommend using silicone in the connection joint, which I was going to test before my spark plug cross-thread cluster reared its head. :faint2:

Here is a picture of it showing the regular collectors. I also have some close-ups posted further up this thread.

http://i1224.photobucket.com/albums/...602_203257.jpg

Are you running a thermostat? my 509 had reversion issues when running on the hose and was very, very cold....it would not warm up without a thermostat. It was so bad that touching the carb was like touching an ice cube... the intake was covered in sweat as well as the risers.... freezing! this was in 70* florida weather with high humidity..... run a thermo and get some heat in the engine and see what happens?? I ended up getting some taller risers and using a thermostat at the same time and no more reversion....

Yeah total brain fart on my end

This is assuming it's truly reversion and not condensation... Ask to speak with Jan direct next time you dial up Lightning.

Borg, I'm not sure how I could convert it to dry with the SC and not burn up the actuators. Those pipes would get really hot with no water going through them. Would need at least a spritz of water in there. Now I have considered installing some type of dump and sending most of the water down the Y-pipe, but I would still need a little bit in there to keep from melting hoses, flappers, actuators, etc.

It's just amazing that I am even having to talk about this. It's not like I'm running some monster cam with 260* @ .050 and 112 LSA. I guess it's just how I roll, having clusters that no one has ever seen before. :snide:

I thought some clarification on my cam choice might be in order. Bob M. had a customer call who was interested in having him spec a cam for him and was worried about reversion. Before anyone gets the wrong idea, I should make it clear that while this is one of Bob's custom cams, it was NOT originally ground for this application, so Bob has no part in the reversion issues with this setup. I purchased this cam from another OSO member who was running the identical cam in his 509 with good results, and the mild specs led me to believe that it would be a good choice for a silent choice setup. In fact, Bob sounded the warning (after I had already bought the cam) that he could not guarantee that this cam would not cause reversion with SC. If I had it do do over again, I would have just had Bob spec a cam for me from square one, but I kind of backed into this build. It was the classic case of one thing leading to another, instead of planning everything out from the start.

Hey Budman II , your honesty is to be commended . Good karma on you !! Black cloud be gone.............:boat:

If I were you I would

1. Sell the lightnings

2. Ditch the silent choice you have

3. Run dry exhaust(no more reversion BS)

Just my two cents

http://www.diamondperformanceparts.c...cat=282&page=1 :coolcowboy:

4. Sell the whole ball of wax and buy a bow rider. Seriously, this thing is driving me to that point! :eekdrop:

Seriously, there are hundreds of people running Lightnings with WAY more aggressive cams than this. Friend of mine is running them on an HP500 with no issues - has had them on there for 10 years. Maybe I'm just cursed.

Dry exhaust would be great to make everyone jump out of the water when it lights off :evilb:, but it would get old in a hurry when I want to go for a cruise and people actually want to carry on a conversation.

That said, I really appreciate all the help and suggestions from you guys.

budman,if you dont have any water in the oil you are worried for nothing.unless your headers are leaking you should be good.reversion happens at idle more than at rpm so quit worring,put the engine in the boat and GO BOATING,i am 99% sure you will be ok.i have seen your cam specs and real reversion should not be an issue.

i forgot to ask,what rpm is the engine idleing at?

I agree with Mike .If you are getting a teaspoon of water in the bottom of headers after shutdown, could just be sweat .That cam isn't near big enough and has wide lobe centers to be a problem .FWIW when I run a seawater equipped motor I let the motor take all the water it wants out of a three hundred gallon tank through 1 1/4" hose.You'd be surprised how quick it will empty the tank .If I were you I would stick the motor in and run your boat..JMO

It's true. Engine's in garage's revert more than in a boat.

there you go budman,you have been told from two wise men and my dumb azz.

Looks like 3 sages to me, go boatn and enjoy your creation you've earned it

What the hell is this crap below ?

Slip on ? Not welded ?

And holes spraying straight down into exhaust stream ?

Huh ? I don't get why, Yuk !

Yeh, I finally looked at your pics. I'm kinda horrified.

Have you noticed any less water with the diverter closed and running through the Y pipe? If your Y pipe shutters are in good shape, it may very well help with your reversion. Shutters and flappers can have a check valve effect; allowing the engine to exhale while making it a little more difficult on the inhale(reversion). I'm only saying that this may lessen your reversion with your existing system. Any engine with valve overlap will have exhaust reversion, but I wouldn't think that your cam would be giving you big issues unless you have long idles through no wake zones. I wouldn't think your Lightnings would be contributing to your issue, BUT if you look at a CMI, the collector is dry and the water is plumbed into the tailpipe after a clever welded conical ring that looks to act as a dam as in the "turbulator" as found in the Merc 8.1 manifolds.

Have you checked your timing?