Compression Check

[Neville Lush]

All good Ken. TA, does your bike have boost senstive mapping for ign and fuel?

 

[warp9.9]

Very good. Thank you! Now that's a response I can believe and also matches what both Scott and ruzzle have said. I will be bringing home a very expensive Fluke pressure calibrator from work and hook that up to the hose on this el cheapo tester I bought (in place of the gauge it came with) to get the real story. Don't know why I didn't think of that in the first place. I suppose there's still a chance the O-ring on the fitting isn't sealing perfectly but my results were consistent with multiple checks. I repeated 3 times - cylinder 1, 2, 3... 1, 2, 3... 1, 2, 3 seating the O ring firmly each time.

However, I've already decided I'm ripping it apart. I did a partial leak down test this afternoon. Did not have the gauge set up to see percent of leakage but simply set the regulator on my air compressor to about 30 psi, removed the check valve from the end of the compression tester hose and blew air into each cylinder with piston at TDC on compression stroke. Took radiator cap off and removed the hose from the crank case vent at my catch can. Visually looked for bubbles in the radiator and listened at throttle bodies, exhaust pipe and crank case vent hose.

Cylinder #1 - Immediately heard air coming out of crank case vent hose and felt it on my arm. It was moving my arm hairs from a few inches away! No indication of air at the other check points.

Cylinder #2 - Very quietly heard air from the crank case vent hose. Could not feel it unless I plugged the hose for a few seconds and then released to let the air escape. No indication of air at the other check points.

Cylinder #3 - The bike immediately started to move forward since it was in gear as rocking it forward was how I turned the engine with a long screwdriver in the hole resting on the piston to see when it stopped rising. Same pressure as the other two cylinders, in gear for each test. No need to even check for leakage after that but I lowered the pressure until the bike didn't move forward. Just a very slight hiss from the vent hose.

So that's enough confirmation for me, it's coming apart. I guess the readings I get with the Fluke calibrator will help me decide if I'll be dealing with 1 piston or 3 and of course what I see visually when I get it apart. This will be the first time I've gone this deep into a motor but with the wealth of knowledge and helpful advice found here on this great forum I feel very confident.

And yes, the previous owner had the bike tuned properly by a knowledgeable tuner but the guy who owned it before him blew a head gasket and replaced it himself. My guess is that's when this damage was done. Maybe it has slowly gotten worse over the last 2k miles it's been ridden. When it was on the dyno they noted that the intake plenum was filling up with oil (listed that way on the receipt he gave me). So the guy I bought it from purchased the catch can but decided to sell it before he installed it. The bike certainly has no lack of power. Can't wait to see what it does with all 3 cylinders at full compression!

well Kent I can say it is fairly easy to change out the pistons and well when I pinched my rings I also tore up the liners in the two cylinders. Most likely you might have got into some cheap gas and it went down hill from there. this all could be done while the engine is still in the bike if you want. I have put a few sets in mine. At least this time you will be able to put a better set of pistons in her. And your probably right about the damage being done before you bought the bike and just deteriorated more as you road her.
you might want to follow any advice Nev might give you on the boost fueling and timing. I know how your feeling but look at it this way. Your learning a lot and she is fixable.

 

[Torque addict]

TA, does your bike have boost senstive mapping for ign and fuel?

Just fuel via a PCV with pressure input module (see attached pic). I'm only running between 9 and 10 PSI boost. At what boost should timing start to be pulled out? And how is that accomplished? I know Dynojet also makes an ignition module. I've also attached the AFR I've been running. It's getting plenty of fuel. This was the tune that was done by the previous owner right before I bought it.

It's an Aerocharger installed by Turbo Connection a.k.a. Boost is Good. They had a proprietary fuel management controller on it which they no longer even use on new installs. They recommend the PCV with boost module its got now. It was put on brand new by the shop that did the attached dyno tune. Something went wrong to blow that head gasket and everything got replaced except the pistons/rings I guess.

At least this time you will be able to put a better set of pistons in her. And your probably right about the damage being done before you bought the bike and just deteriorated more as you road her.
you might want to follow any advice Nev might give you on the boost fueling and timing. I know how your feeling but look at it this way. Your learning a lot and she is fixable.

Agreed about the learning experience. I'm also excited to confirm there is indeed a problem and get it running correctly. I'm betting this is the reason behind the shuttering I'm experiencing at lower RPM with greater than 5 PSI boost. It's just never been quite right and has always spewed tons of oil. This means I've yet to experience what it can truly do and the dyno sheet I've posted isn't its full potential. I needed to redo that lower timing gear and chain guides from the update kit I bought anyway as well as put an MTC clutch in there so I will be killing many birds with one stone.

By better pistons do you mean higher compression or just higher quality? It would be nice to get up to 250-260 RWHP but don't know if that's possible with the air flow restriction of stock headers and a turbo. Not sure what kind of boost I can even get with that turbo.

I'm willing to consider doing some upgrades here but unless you guys direct me what to buy to accomplish this it's just going to get all factory parts. I'm all ears. I'm already thinking I'll put in those Carpenter head bolts though.

 

[warp9.9]

Just fuel via a PCV with pressure input module (see attached pic). I'm only running between 9 and 10 PSI boost. At what boost should timing start to be pulled out? And how is that accomplished? I know Dynojet also makes an ignition module. I've also attached the AFR I've been running. It's getting plenty of fuel. This was the tune that was done by the previous owner right before I bought it.

It's an Aerocharger installed by Turbo Connection a.k.a. Boost is Good. They had a proprietary fuel management controller on it which they no longer even use on new installs. They recommend the PCV with boost module its got now. It was put on brand new by the shop that did the attached dyno tune. Something went wrong to blow that head gasket and everything got replaced except the pistons/rings I guess.



Agreed about the learning experience. I'm also excited to confirm there is indeed a problem and get it running correctly. I'm betting this is the reason behind the shuttering I'm experiencing at lower RPM with greater than 5 PSI boost. It's just never been quite right and has always spewed tons of oil. This means I've yet to experience what it can truly do and the dyno sheet I've posted isn't its full potential. I needed to redo that lower timing gear and chain guides from the update kit I bought anyway as well as put an MTC clutch in there so I will be killing many birds with one stone.

By better pistons do you mean higher compression or just higher quality? It would be nice to get up to 250-260 RWHP but don't know if that's possible with the air flow restriction of stock headers and a turbo. Not sure what kind of boost I can even get with that turbo.

I'm willing to consider doing some upgrades here but unless you guys direct me what to buy to accomplish this it's just going to get all factory parts. I'm all ears. I'm already thinking I'll put in those Carpenter head bolts though.

no not higher compression just better pistons I know J&E makes them and I am sure there are others. I remember Darrel I think had some new turbo pistons made for his rocket.

I believe they made 8:1 9:1 and I think a 10 or 10.5 :1 pistons.

 

[cardinal93]

This right here I a graduate level thread, not sure I should even be reading it
You guys really are amazing and make this forum so much better than the average

 

[Neville Lush]

FWIW the stock pistons will be fine IF you have a good tune, I have seen close to 300hp with stockers for many kms.. It would be a great idea to change cams for forced induction , but it seems a natural trait of all kit builders to slap the kit on a stock engine. See if you can find one manufacturer who sells a turbo vehicle with the same cams/cam timing as a NA engine. If you are running 10psi with the stock engine and continue to do so, you need to find a proper tuner and get the ign mapping boost sensitive as well.

 

[Torque addict]

Thanks guys. If I do nothing else I will add ignition control. I'm debating between the Dynojet ignition module that piggybacks off the PCV and the J&S Vampire unit that Warp has. I will run the situation by the tuner that I've used in the past for my other motorcycle and get his thoughts.

Quick question… with a variable vane turbo wouldn’t I want to be able to retard timing based off rpm in addition to boost? Unlike a supercharger, I can instantly have max boost at only 2500 rpm by simply cracking the throttle. Wouldn’t I need more retard there than max boost at 6500 rpm? Timing could be added back in as rpm increased with the Dynojet but I don’t see how I’d do that with the Vampire unit. I really like the knock sensor on the Vampire though, but as a safeguard only. Since retarded timing reduces power isn’t the goal to retard only as much as absolutely necessary?

Warp, the only Rocket pistons I see on the JE sight are 10.5:1 and 11:7:1. Maybe the 9.1:1 are custom order? I do like the sound of that. Don’t see anything at the Wiseco site for the Rocket. That’s as far as I’ve checked for now. Unless I need to replace all 3 though, which I doubt, I’ll probably just stick with stock. I have confidence in the dyno tuner I use and I've read many places where you too have commented on how stout the stockers are.

Will just stick with the stock cams too but it’s nice to know I could do that if I wanted. Always thought the restrictive combo of stock headers and turbo made that a bad option. Thanks for the clarification Nev.

 

[ruzzle]

The Vampire unit senses each cylinder individually for early signs of imminent detonation.

When detected, it retards the ignition on THAT cylinder only by two degrees. If that doesn't fix it, it retards that cylinder by another two degrees ... and so on up to (I think) ten degrees total. All very rapidly.

When/if the detonation disappears, ignition timing is restored. So it only retards individual cylinders enough to get rid of the Detorats.

If you have the warning lights option with the kit, it flashes lights at you to tell you which cylinder looks like playing up.


BUT.... if it's that close to detonation, it hasn't been tuned properly!!

 

[Torque addict]

BUT.... if it's that close to detonation, it hasn't been tuned properly!!

Which begs the question with the proper amount of fuel (a good tune/AFR) does any timing really need to be taken out? If I was having detonation now I would have 3 dead cylinders instead of just one, which I still maintain was damaged prior to the PCV and tune that's on the bike now. Boost is good/Turbo Connection has done plenty of these kits with just remapping fuel.

In addition to the safeguard features on the Vampire that you mention, which would be nice to have even with a good tune in case of bad gas or something going wrong in the fuel system, it also has a boost input to retard timing in a predetermined fashion to augment a good fuel map but it doesn't look like it can account for high boost at lower rpm's that can be present with the turbo I have. That might not take enough timing out sometimes, or too much at the top end depending on how it's adjusted. There's no software, just some dip switches and pots. Then again, I'm probably just talking out of my a$$. Hoping Nev or Warp can enlighten me.

 

[Neville Lush]

I repeat," If you are running 10psi with the stock engine and continue to do so, you need to find a proper tuner and get the ign mapping boost sensitive as well.." or I guess you can leave it how it is and blow the head gasket again and bugger the rings again. The cost of a Vampire unit will be more than an ign module.