Clicking noise/ low compresson on #1
 

I may have done a bad thing. First a little background. We were at the MiDiv event in Topeka, running the small pulley for the first time at less than 6000 feet. Boost was in the 14-16 psi range. It's a '99 motor with an Ubercharger, 750cc injectors and an EManage Ultimate. Friday and Saturday had no issues except an occasional splutter at partial throttle. We have been having that off and on anyway. Sunday after the 4th run, it came in making a ticking sound from what appeared to be the valve train. Power may have been down a little and the splutter was worse. The plugs all looked okay to slightly rich. We made three more runs with the ticking getting louder. I elected not to take my fourth run.

I have pulled the belt off the blower and spun it by hand. No noticeable noises.

I removed the valve cover and inspected the springs/lifters. Nothing appears amiss.

Compression test shows 120/160/160/155 dry. I have not done a “wet” test.

Any guesses at this point? What are my next steps? Wet compression test? Leak Down test? ( I am not sure I know how to interpret one and don’t have a tester yet )

Pull the head? Or just go ahead and pull the motor?

Posting on Miata.net as well.

Cylinder w/120 is hurt. Do a leakdown test and figure out what is "hurt". Read this thread:

https://www.miataturbo.net/forum/showthread.php?t=21823

and then check all the HLAs on the 120 cylinder to see if any of them are collapsed or stuck open.

Hi Chris,

What Fuel rail are you using with your 99 Motor and is it single or Dual Feed? I've heard from Multiple people with 99-00's who have had #1 get low on compression and have usually seen signs of detonation when they tear the motor apart.

This is one of the reasons for our Dual Feed Rail, and even why we like placing the dampener on an NB in the middle of the rail.

That and a "wet" compression test are next on my list.

It's a '99 motor so it has solid lifters, although I could have lost a shim which would account for the noise, but not the loss of compression. I didn't find any "extra" parts when I pulled the valve cover.

I am running the '99 rail converted to return style. It still feeds from the back, but returns the fuel from the front to the tank. When we pulled the plugs Sunday morning things looked fine. The plugs i just pulled all appeared rich.

Thanks for all the suggestions. I will do some more testing tonight and likely just pull the head. I am wondering if perhaps a rod bent a little. I plan to check the valve lash before I pull the head as well. I am having troub le accounting for the clicking. A bent or burnt valve would likely loose more compression wouldn't it? Does a bent rod click?

Wait till leakdown to pinpoint for sure if it's the block or the head.
I can see it being a slightly bent rod.
One more reason to go with a bigger bore dual fuel rail ( ;) Marc)

Do you have a form of knock sensing?

I bet it was really high intake temps combined with knock.

What the highest anyone has ever safely run a supercharger on our engines?

I was going to vote shim, but figured you could have seen that when pulling the cam cover. Though, I have seen the shims split and that might also cause valve issues. I hope for your sake it's that simple. Clicking definitely sounds better than knocking. ;) Good luck.

I'm throwing this out there just for the sake of suggestion, but the donor block I'm using in my build had a loose rod cap and bearings in cyl #3 and would "click" when the piston reached TDC and then started it's movement downward. Not sure how that would affect your compression though, unless you already had an issue there.

If you're pulling the head and don't want to pull the engine yet, the best way to test for a slightly bent rod would be to turn the crank by hand and make sure that each piston is reaching full TDC and evenly. And I found that the way to test for the bearings is to get each piston to TDC, then turn the crank slightly to get each one to just barely start moving downward, and see if you can push the piston down any by pressing on top of it with your hand. If it moves down at all, it's going to be a bearing/cap. Also make sure piston 1/4 and 2/3 move perfectly with each other. Sorry if you know this information already, but it's a test I just used on my car and donor block and was very effective.

Thanks for the input guys. I still have to check valve lash and do a leak down test before I pull the head. Hopefully I will get to it tonight.
It would be nice if it were a shim, but it's hard to picture that causing the compression issue.

I don't know if a bent rod clicks or not. Anyone have an idea?

This was supposed to be the last event on the EMU. The MS-II and Knocksense are sitting on my desk. Oh well.

One other data point, it's a FOUR MONTH lead time if you want a 2.0 stroker from FM. ( just looking at options for the worst case scenario which is probably a rod)

I think a bent rod would only click if it were bent so bad that it's contacting something. But if that were the case, it would look like mine did, and your engine would probably not be running at all.

Chris,

Hurt bearings, loose rod caps and a bent rod could all possibly cause "a click".
Without tearing the engine down, you should still be able to diagnose a piston that is not "coming up all the way". A dial indicator with a long extension and a sparkplug adapter should enable you to make relative (not absolute) measurements of how high each piston goes in your engine. If your 120 cylinder is "lower" than the other 3, you may have a "rotating problem".

I'd still do the cylinder leakdown test first. With that done, you'll be able to see if you have leakage past the the rings (broken ring lands, hole in piston, cracked piston), the intake valves (valve or guide) or the exhaust valves (valve or guide).

I agree with your hypothesis that is unlikely that a solid lifter shim could have "skipped the bucket" and caused the clicking or loss of compression problems (My bad in prior post on HLAs, didn't realize that you were one of the "lucky ones" with solid lifters)

FWIW, I really don't know how anyone can cost justify a FM 2.0 stroker! Get a set of H beam forged rods, a good set of forged pistons and spend the difference on a full ball bearing GT turbo with a good tubular manifold and external WG piping...I think you'll be way ahead...but YMMV.

I agree with the rods/pistons, but why would I want a turbo?:)

The FM motor might have been a quick option. I have about 6 weeks before the car runs in the SCCA Solo II National Championships, and way to many other commitments in between.

I was rotating the motor by hand last night doing a leak down test (which I either did wrong, or it didn't show anything significant) and found that things got really hard to turn as the #1 piston reached BDC.

I will tear more of it apart tonight and over the weekend so that I at least have a diagnosis and parts list by Monday.

[QUOTE=Chris Swearingen;293877]I agree with the rods/pistons, but why would I want a turbo?:)

Ooops forgot you were a "blower guy"...bag the stroker motor, add a Meth kit and have enough let over for a lifetime supply of methanol :)

sn95, Chris already has WI, though at present it's a simple on/off system, no controller.

Chris, sounds like you're on track. You've got a bad noise, and some funky datapoints. You know it's not on the topside, so the head's coming off. Once that's done, you'll be able to visually see the problem- either a piston's gonna be burned or one of 'em ain't gonna come up to the same height as the others. Resistance while turning isn't encouraging- plugs out, I assume?

THAT sure sounds like a rod. I was going to say valve lash (just cause I have that issue myself, skipping cyl and a ticking sound - though that tick might be unrelated) - but what you're describing is EXACTLY what I had when I bent a rod a long while back.

The rod bent enough the piston skirt contacted the crank counterweight. Low compression on bent rod cyl, and very hard to turn at the bottom (stretching rod slightly). I've bend rods twice, both times I could tell just by putting a dowel in the sparkplug hole, turning the motor over and seeing how high the rod gets at TDC each one.

I'm not sure what the EMU you were running does, but the last time I lost a motor, it was that - bad handling of altitude.

I have prevoiusly diagnosed a bent rod before by taking a long screwdriver placing in each cylinder and made a mark on screwdriver once reached top dead cylinder in cylinders that compression was good in. Then checked low compression cylinder and was not the same is not very accurate but worked for me. We were pretty sure it was rod because compression was low in one cylinder but leakdown was good in all cylinders.

Good luck maybe it will be something minor but doesnt sound like it.

Yay! I'm not alone in thinking the stick test will work. :-)

Anybody else think these pistons should be at the same level?

Looks like a rod to me. I will get pictures of it after the motor guy disassembles everything for measurements Monday or Tuesday.
http://www.systemstrategies.com/miat...od/bentrod.jpg

I sense an upgrade in your future!

Unless you were already upgraded. Either way, I do forsee unavoidable expendetures. :-( Hope the rods are all that's bad.

Update: Give that man a cigar!
The motor guy disassembled everything. No metal in the pan or anywhere else it shouldn't be. But he did find something interesting. I hope you are all setting down. I didn't just bend the #1 connecting rod, I bent ALL FOUR.
I will get pictures after I get all the parts back.

So to add to the collective wisdom: Stock '99 Miata rods will handle 200 HP, but at 225 to 250, bad things happen.

I have to have the motor ready to go for the Solo II National Championships in Topeka the 18th and 19th of September. That deadline really limits the options available to me.

I found out I couldn't buy a new built motor. No one got back to me on the used built motors that were for sale.

SO...

I called around looking for pieces and parts that were in stock. The good folks at Flyin Miata came through for me. They will ship the following this afternoon ( I ordered this morning)

Carrillo H-Beam rods
Weisco +1mm Pistons (9.0:1)
Oversized intake and exhaust valves
A valve spring kit
ATI Superdamper
145mm 6rib supercharger pulley for ATI damper

I don't know how much of a "build" thread I will be able to do. In the essence of time, I am having all the motor work done by a highly respected local motor builder. He mainly does big block chevy type stuff, but also does spec miata motors, and is crew chief for one of the MX-5 Cup teams, so he has seen a miata before.

I will keep you posted on the progress.

That sucks, but is good news. :-) A little pricey, but it should work. Too bad you can't put it all together yourself, it's fun when you have the time, and a lot cheaper obviously. Then again, compared to the price of the parts it won't be too bad.

I got some used H-beams a while ago, run '97 pistons for the lower compression.

The history, when I first turboed my '00, I put on a used FM-II kit. Had no boost gauge, an incompetent friend watching the LCD-map. The wastegate actuator was broken (didn't know this. I'd tested the HELL out of the EBC, but never the diaphram), and there was a bad ground on the ECU.

So long about 20 psi, the piggyback stops pulling spark altogether. Bent at least 3 rods, I stopped checking too close after I found one that was bent in two seperate axis. I was having piston-counterweight interference.

Got a set of used '97 rods and pistons, assembled - had a mutual mistake with FM which they were awesome and took care of - put it all together, and much later down the road, bent all of those.

At the time, I'd heard there's a different part number for the '99+ rods, some theories that the early rods are shot-peened or somehow treated, which the later cars were not. They both saw out-and-out abuse.

The last time around (still using the 9.0:1 '97 pistons) I got me some used carillo H-beams for cheap, like, <$500, and nothing that I know of has gone wrong since.

I don't think 200 hp is any magic number, I think it's bad tuning. People are making more than that, but you have to do it right, have reliably timing control - that's almost everything.

What ECU are you running? I thought it was a MS-I, meaning you're using the CAS sensor, and that can easily have 5 degrees of jitter.

If you're serious about making bigger power, you should really use a timing wheel. If that's not it, then, bad luck, but you'll have a bullet proof motor now so enjoy. :-)

I would have been the first to admit if it was a tuning issue, however the car has seen hours of dyno time building that tune, was purposely tuned a little rich knowing we would be going to sea level, and showed no signs of any ignition events.

All that said, I was running an EMU which I had zero complaints about at 10-13 psi and 460cc injectors. When we upped the boost to 12-14 and moved to the 750cc injectors, things were good under hard acceleration, but we were having some problems modulating things effectively at partial throttle. No amount of dyno time was taking care of it. So I conned Joe into building me a MS-II to handle four primary functions I can't do with the EMU.
1) better control over the 750cc injectors at partial throttle
2) support for a flex fuel sensor to support various mixtures of e-85
3) the ability to drive a coil on plug setup and adjust dwell
4) accept input from the KnockSense MS and act on it


Edit: the MS and knocksense are both on my desk to be installed immediately after break in on the new motor

That's a pretty bold statement to make, considering the number of people who are making that and more on stock parts. I'd take a long hard look at your tune before saying it was a mechanical failure. Just because you are running rich doesn't make it safe. I'm sure it was knocking like a mofo, you just didn't hear it. I wonder what your AIT was when it failed.

Good luck to you!

You are probably right, and I defer to your greater experience, please send me a list of the folks making in excess of 225 rwhp on stock '99 rods and I will apologize to each of them.

There are a lot of dyno charts (take them for what they are) floating around out there showing in excess of 225whp on a stock 99 motor. You'll have to compile your own list of people you've offended, I'm too lazy.

Are the '99 rods unique? Or are they the same as the rods from a (for example) 2001?

And I don't have greater experience, you see I'm still on my original '93 motor :)

Heh - I'm pretty sure I was running on them, for a long time!

Oh, wait, those were '97 rods. But still, I ran SEVERAL blocks under high boost on '00 rods. :-)

Nonetheless, FMs claim is you need better tuning to pull it off.

All the fuel in the world won't save you from bad timing!

I still have SERIOUS misgivings about this CAS sensor on your motor. You're putting way too much money into this to not use a trigger wheel. A stock '99 wheel would be fine, a $30 36-1 wheel would be even better.

But, maybe your machinist will have a discount if you do two builds in the same month. :-)

Got the old rods and pistons back from the engine builder today.

http://www.systemstrategies.com/miat...entrod_005.jpg
http://www.systemstrategies.com/miat...entrod_006.jpg

Any underskirt damage? I saw it either on the skirts, or on the wrist-pin-holder, whatever you call that web of material.

They look so familiar. :-) Anyway, good luck with the build.

Always seems to be number 1 cylinder (worst) on a 99-05 when using a stock Fuel Rail. I know I sell fuel rails, but I would recommend the upgrade, especially when everything is out of the car!

There are a bunch of people running 250hp+ on 99 engines! I was at 199hp at 9 psi and I just turned it up to 10.5psi on the weekend. Probably go more soon.

Wow, that #1 looks almost as bad as mine! Of course, mine was bent so badly that the wrist pin sleeve was contacting the crank counterweight and stopped movement altogether.

Got a selection of dual feed fuel rail blown motors whose rods you can show us? After I see five or six bent rods which are evenly distributed where they were running dual feed, it'd be a much more convincing argument.

After all, all the miatas I've seen with bent rods were running rubber tires, perhaps we should change that too? :-P

http://abefm.smugmug.com/photos/126429973_4z5wG-M.jpg

Tell me which rail I was running here...

Just for eye candy:

http://abefm.smugmug.com/photos/54089787_uwLjD-L.jpg

And from the side:

http://abefm.smugmug.com/photos/54089683_dCBjH-M.jpg

Yep, that rod has three bends in it, in two axis. Pretty destroyed!
Not sure* what order they were in the motor, though, and there was a timing issue, so it's not a good "rail" test. The other post, though, was from running lean, I believe.

Oh, one more from this first rebuild:

http://abefm.smugmug.com/photos/54089795_pNZ4h-M.jpg



*Turns out it was #3 that got the worst of it this time. Found a pic in the block.

To the OP: What were your intake temps? Are you using an intercooler at 10psi? I dont remember seeing anything about an intercooler there.