Frank, what abour fabricating your own squirters out of copper tubing & brazing. A/C fittings should do the trick & nozzles should be pretty easy to fabricate. Maybe $20.00 in fittings. Figure volume through each nozzle VS. oil pump volume. Seems that the nozzles shown on that site taper to give a stream. You could do irrigation type jets that would provide a mist. Or check a Mcmaster Carr catalog & find something more suitable. Even the misting effect shoiuld provine significant cooling effect, as we all know by them personal mister bottles you see everywhere. Worst case, it'd cool the rods & surrounding block volume.

Ed

I would try to mock up the accessories from the monty on that engine with the timing covers removed. If it all fits, you should be able to bolt on the pickup tube & pan.

I'm thinking the Diam pump might have more volume designed into it...

Ed

The blocks appear identical except for the knock sensor plate bosses. Before I spend money on boring the Diamante block, I'll bolt on the accessories and make certain everything fits.

I'd like to incorporate piston oil squirters, but I'm not interested in experimenting with them when I don't know the oil pump flow rating - or what will happen to gallery flow/pressure if I tap the main gallery to supply the squirters. Note that most of the squirters in the article have a pressure spring to stop oil flow at idle/lower oil pressure to insure sufficient oiling at reduced rpms. An engine might be quickly ruined if the springs weakened or stuck. Any squirters that I might fabricate wouldn't incorporate the pressure trip springs, so there would be a danger of insufficient lubricating oil flow at lower rpms.

I'll add an engine oil cooler - not the same as piston squirters, but better than not having one.

Frank

I've always wondered why the bottom of the pistons couldn't be squirted from the pin oiler supply, like the thrust side of the piston is. Just two more drilled holes, and toward the top of the rod pin boss in the less stressed zone.

The concern is the pistons are going to run too hot.

Your boost level is in a range that I dont think you need the oilers. Ok ... you did melt a piston, however once you get detonation any piston will melt.

The high velocity of detonation scrubs away the thin layer of air that serves as an insulator in the combustion chamber. As this layer gets scrubbed thinner heat transfer goes up dramaticly.

There is nothing that will keep a piston that is in prolonged detonation from melting. Forged will help since they transmit heat better. Non isolated skirts ( no groove in the oil ring) helps get the heat to the water jacket.

Steel rings conduct heat about 15% better and the top ring is the major heat transfer path for the piston, so it does help.

But.... IT still all comes to this, detonate and all the extras do is buy you some more time until the piston fails: it still fails.

Get a compression ratio that gets the cyl pressures in a decent range, use some type of boost retard on the ignition, get a plug thats not too hot under boost and make sure the fuel supply is there and you won't have any melted pistons.

If you could get a detonation sensor that dropped the timing back that would help a lot if somthing goes wrong like you get an unexpected lean out.


Kevin C

If you are going to be building a forged motor you do not need oil squirter's. There only really needed for cast pistons.
The nice thing about not having oil squirter's is you then get more oil to the main and rod bearings. And the cams.
I was reading on here that some one said that 20-24degs of timing would take out your rod bearings. Not true. Knock is what takes out your rod bearings, or bends a rod. In my Galant vr4, I run 28-32psi of boost(turbo is a gt30r) depending on track prep with a max timing of 23degs. Never once, have I had a bearing go bad, From to much timing.
Once you get the rig up and running and you have a nice engine management system that can read knock. Get a good base line tune. Then from there set you boost that you would like to run. If the engine is not knocking start adding timing in tell you see knock. Once you see knock stop and take out a deg of timing tell knock goes away.

Oh and if using megasquirt take your time on the tuning. I have see a lot of people kill there engine using them. Most all the the cars I have see blow up using megasquirt was because the people got the kit and did all the soldering of the boards there selfs.

Kevin -



I agree.



I'm not yet certain that I did since I haven't pulled the head - but there was enough detonation to blow the head gasket and at least SOME damage was done to the last piston in the fuel rail order or I wouldn't have found aluminum specs on the #6 plug. My concern that I holed a piston was because the sump was pressurized after detonation - I s'pose it could be only a blown gasket, but I won't know until I tear it down.... won't be long until I get a look at the damage.



I agree - and I have the machine shop looking for forged piston options. For the amount of boost, I consider forged pistons overkill, but worth serious consideration - particularly if I try to go beyond 7 psi to the blower limit. Another option might be coating the pistons - my choice between only the two is forged - particularly if they're custom CR.



Yep - as stated, pistons are being searched now, MS2 includes full spark map control w/boost ignition retard as desired, plugs will be 1 or 2 ranges colder than stock and the fuel rails have been reworked for dual feed/constant pressure.... and will include larger injectors needed to run at the constant fuel pressure.



That's why I hope to be able to use the Diamante block - it has the detonation sensor mounting plate - not the best arrangement compared to a direct mount to the block, but I don't see a good place to mount a sensor directly on the 3.0L block. I plan to use a GM sensor on that plate - it'll connect to a Knocksense translator:

Knocksense

Using that unit for a signal (or I can build a unit onto the MS board) MS2 has the capability to further retard the ignition on knock detection and sneak back up to knock threshold if desired.

Brian -



I agree, but forged do give a small amount of safety margin. I don't particularly like forged pistons - or their cost - but I'm interested in dropping the CR back to maybe 8.5:1. The cast 8.9:1 pistons are ok, too - if I don't put more than 7 psi on it - just trying to get the most bang for the buck and leave a little headroom if I want to try to max out the blower (which I haven't yet done).



I agree - if the squirters were designed for the block - and IF the oil pump was designed for the application combination, I'd use them..... but I don't want to be on the leading edge of that experiment.



I have no idea how much spark lead I can use until I start tuning, but I *think* the prior problem was a fuel issue. I'll give it whatever spark lead it wants... the main issue may be finding a good dyno to use. I'd like to find a steady-state dyno, but will probably have to trailer the truck to somewhere around Charlotte Motor Speedway to find a good shop.



Thanks for the warning - I did do all of the PCB soldering myself - hopefully it's ok..... seems so on the stimulator.... so far. I do plan to take my time, though.... there's a lot about MS2 I don't yet know.

Frank

You're gonna use an entirely different block because it has provisions for a knock sensor?

I think I'd be drilling, and tapping a hole somewhere on my block that is already machined, and running.

Mostly, yes. If forged pistons are used, the old block would have to be rebored anyway to set the correct piston/bore clearance. Also, the old block wasn't decked on the prior rebuild - it wasn't too badly etched, but did have some minor etching.... fine for a N/A engine, but the addition of the blower didn't help that situation.



That was my first consideration, but I don't see a good location on the 3.0L block. The most logical location is near the skirt flange, but room is scarce... plus the heat from the exhaust manifolds isn't good for the sensor wiring.

Since I bought the entire engine for $325, there's not so much invested in the block - particularly since I gained an extra crankshaft and a set of heads. Some of the Diamante specific parts can be sold for a few bucks if I choose to make the effort, further lowering the cost..... and if I want, I can rework the old engine as a backup - or repair whatever damage and rebuild it as a N/A engine... keep it or sell it.

The main concern is how well the knock sensor arrangement will work. I've been told that Mitsubishi stopped using knock sensors for a time because they didn't work as well as intended, but later started using them again. I don't know if the problem (if any) was because of the location of the sensor on a plate instead of directly on the block.... or if the early ECU software wasn't refined to the necessary extent for reliable operation. I know very little about the use of these sensors, but understand that the placement of the sensor is somewhat critical to function, as is the tuning of the frequency range and software parameters. From what I've read, different block designs require specific locations for proper knock detection with minimal extraneous noise which may provide false signals. An example would be the change in location on the Corvette engines over time with different variants. I figured that Mitsubishi engineers likely did quite a bit of work in determining the best location for a sensor on the 3.0L block and chose the mounting plate method for a reason, particularly since it was a lot more expensive to produce another set of block molds to incorporate the plate, bore/tap 4 holes plus the cost to develop and produce the plate.... instead of just bolting the sensor directly to an existing block location. Surely there was a reason. Still, I don't know how well the arrangement worked - and if the GM-type Bosch sensor will work any better - or as well.

Mostly, the idea is to do what I can to make it better suited to the purpose.... within reason.

Frank

It probably doesn't mean anything, but pretty much every GM V-type engine produced since 1999 has the knock sensors (2) in the valley sort of like your Diamante pictures.