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I have some slap in the morning, but my car burns zero oil and runs great. It is important to follow the piston manufacturer recommendations for wall clearance and ring gap. Not the ring manufacturer or mazda recommended specs.
EDIT: sorry I'm reading this from a plane, below is not relevant if you've already checked. Carry on
Right. The Supertech instruction spec'd tighter clearances than the wiseco pistons I first used (which subsequently failed at ringland anyways knocking out my efr6258 back in 2014.) the coefficient of thermal expansion was different for the differing alloys used.
If he switched from Supertech to wiseco, he might need to mind those clearances. Grabbing numbers from my butt but if I recall anything Supertech recommends something on the order of 0.0028" where wiseco wants up to 0.004" or possibly more. Those pistons might expand in the bores more than the Supertech and would make for some amazing noises and pictures later.
(Trying to) put this to rest...the original ST's were installed loose - looser than recommended. The machine shop that the block went to for that was less than desirable (as in, during the 2 month stay at the shop, the owner went out of town, let my block sit idle for 3 weeks, then jobbed the work out to a second shop where it sat for almost a month before I tracked him down and located my block). In the meantime, the specs got lost in the shuffle and the block got bored out to a "best guess". I ran it like that because I would have had to have the block bored to 40-over and order a whole new piston set - I didn't have that kind of coin at the time. I didn't have any piston slap with the ST's and didn't burn oil - so I left it...for 5 years.
Now, with the Wiseco's, they measured between .0035 and .0038 PWC after honing, Wiseco says .0035 is the right number so I trust that number. Now, if .004 or more is the right number, then...as psyber says, it might make for some amazing sounds and noises later.
Anyway...I spent the week (after work) doing some work on the head. Cleaning it, inspecting for damage on the valves and seats (and found some nicks in the dome of the combustion chambers of #3 & 4 where the damaged pistons were, and no marks on the valve seats or valve faces. That seemed VERY odd - I expected major carnage there - with bits of piston slapping around in the chamber...pero nada. So I cleaned out the carbon and the head's going back together tonight.
If all goes well, the engine will be back in the car by Sunday and we'll see how long before this one blows!
I used .035" on my Wiseco pistons and get no audible piston slap on cold start. I ran Wisecos for 8 years prior and piston slap didnt start until a couple years later when they started wearing a little bit.; Thats not the first time Ive seen someone post about broken supertech pistons in that same spot, I think the wiseco piston is just better and its stronger too.
I used .035" on my Wiseco pistons and get no audible piston slap on cold start. I ran Wisecos for 8 years prior and piston slap didnt start until a couple years later when they started wearing a little bit.; Thats not the first time Ive seen someone post about broken supertech pistons in that same spot, I think the wiseco piston is just better and its stronger too.
Yeah, I thought that ST's were good - I hadn't hear anything like this either.
Anyway, the engin is 80% assembles;
I've got some AN hoses to re-do and a few things to tidy up. The new clutch plate went in, and the trans went back on last night. I plan to have the engine back in the car this Saturday.
It's been a long time since my last post so just to bring everything up to date;
- The engine went together well. Started up nicely and there was no discernible piston slap (so...put that question to rest in my mind).
- Break-in was un-eventful so I settled in to tweaking my tune for the new setup. All of the "likely suspects" got adjusted (VE, spark map, minor ASE and WUE tweaks, idle settings, etc...).
Then I had a semi-minor wiring catastrophe (foolishly was re-wiring a pair of 12v DC to USB supplies that were powering an in-dash tablet and a phone charger port with the battery still connected - touched the wrong wires together on an un-fused circuit...and the rest is history!). I released LOTS of "Magic Smoke", and torched my ancient Nexus 7 tablet (RIP "Old Faithful"). So I decided to use that as an opportunity to take out the dash and re-wire the whole kit-and-kaboodle, as well as make some "strategic modifications".
Up till then I had some severe heat-management issues behind the tablet install (which took up the space where the old radio/tape player was). It would get so hot in that small space that the battery in the tablet would stop charging (I even had to replace the original battery in the tablet). I resorted to putting some CPU fans inside the space behind the tablet to vent the hot air out. The fans were controlled by a digital switch connected to a temperature sensor that turned on the fans when the temp exceeded 95F - which it did quite often in the summer. It worked...just barely - because the fans weren't ducted and weren't properly oriented to exhaust the hot air properly.
With the dash out, I was able to re-think my heat problems and decided to put the fans inside the main duct to the eyeball vents in the dash and put in some additional air management from the exit of that duct, to the back of the tablet. That way, when the fan turns on, the heat is pulled from the tablet and into the duct and eventually gets vented into the cabin!
Besides all of that HVAC work, I also have been dealing with a "smoking issue".
With the rebuild of the engine, I changed the size of the turbo oil-feed line from -3AN, to -4AN. At the time, I didn't think that made any difference...boy, was I wrong! Every morning, after a cold-soak, the car would smoke like a 60's-era ad executive. After things warmed up, everything was good. Obviously, I was over-oiling the bearing in my Churbo. So, I tried the "punched-out pop rivet in the oil feed fitting" trick. That helped, but not enough. So I purchased a fancy-schmancy oil feed fitting with replaceable jets (from Vibrant), and used the smallest jet size. That didn't work either. I think that the root-cause was that the bearing is so sloppy that it would leak when cold and would only seal when it got hot from thermal expansion.
What I needed was a way to stop the oil flow to the turbo when it was still hot prior to shutdown and then re-start the flow after the turbo heated up a bit.So I decided to go semi-low tech and put a solenoid in the turbo oil feed line, connected to a switch in the cabin. I also added an oil pressure switch to the outlet side of the solenoid so that I would know if the solenoid failed and there was no oil going to the turbo (it's a N/C solenoid). The output from the pressure switch goes to a LED that's right in my face so if the solenoid fails (or I forget to switch it on), I'll know.
Could I have reverted to a -3AN line? Yes, but I don't think the problem was with the bleed line, or the restrictions.I think the problem is in the el-cheapo turbo. So far, it all works like a champ - my car has become a non-smoker (and I'm so proud)!
Damn! Has it been a year and a half (or more) since i last posted in this thread? My, how time flies...
Anyway, I was at Road Atlanta yesterday for a TNIA and besides being totally intimidated by the track, my EBay radiator finally decided to crap the bed during the first session so I was DNF for the rest of the day.
So I'm online today, looking for a suitable replacement. I've kinds settled on;
- Koyo "V-core", or the
- Mishimoto 36mm
Any preferences (or other options)? I'd like to keep the cost under 3-bills if I can.
Koyo Hyper V or CSF. Will a 36mm cool your HP level? I think you have hood vents, don't you? So, perhaps. Otherwise, you would need to step up to one of the big boys from Supermiata or Trackspeed (now supplied by Doward at Tarmac88)
Koyo Hyper V or CSF. Will a 36mm cool your HP level? I think you have hood vents, don't you? So, perhaps. Otherwise, you would need to step up to one of the big boys from Supermiata or Trackspeed (now supplied by Doward at Tarmac88)
I'm sub-300whp (I've got some Virtual Dyno pulls that say 310 with 210 kpa of boost, but I don't believe that for a minute - it's a Chinagharger for Pete's sake) probably 225 whp at best, so I think the 36mm will work just fine. Yeah, I've got Singular hood vents and radiator ducting so that should help.
That CSF rad looks interesting (new to me), and at 42mm it might be a good middle ground. Anyone else have an opinion?
I was in your shoes on the radiator debate and finally went with Trackspeed.
Why? Because while on paper it's seemingly more expense than all others, except the first time I have to pull in/let off early from a track session due to cooling issues, I'll be cursing myself for skimping. Between missing session(s) and travel expenses for going to a track, it would eat me up if I didn't do everything I could to ensure success. Got tired of limping my way through track events with an ebay aluminum radiator that never adequately cooled.
I was in your shoes on the radiator debate and finally went with Trackspeed.
Why? Because while on paper it's seemingly more expense than all others, except the first time I have to pull in/let off early from a track session due to cooling issues, I'll be cursing myself for skimping. Between missing session(s) and travel expenses for going to a track, it would eat me up if I didn't do everything I could to ensure success. Got tired of limping my way through track events with an ebay aluminum radiator that never adequately cooled.
Buy once, cry once.
I truly understand the point you're making, BUT I pulled the trigger on the CSF rad. It's 42mm (17%-ish "beefier" than the 36mm Toyo for the same price), so that has got to be good. And from what I've read, the build quality is top notch. So, it's not multi-pass, so I'll lose some street cred, But I never had any problem keeping the temps down around 190*F with the trusty old EBay crap-adiator.
Okay, I have irrefutable proof that my car is sentient. Today I went into the garage to see how much coolant puked out overnight, since on Sunday it looked like about a cup of coolant had leaked out after a quick warm-up drive. To my astonishment, the floor was dry! So I thought, "Okay, I'll repeat my warm-up drive and see what happens". What happened? NOTHING! No runs, no drips, no errors.
I think that my car "knows" that I had ordered a new radiator, and it was "behaving itself" - trying to lull me into a false sense of security. Little does it know, the new rad will be here by Thursday and we'll see who's BOSS!
Okay, I have irrefutable proof that my car is sentient. Today I went into the garage to see how much coolant puked out overnight, since on Sunday it looked like about a cup of coolant had leaked out after a quick warm-up drive. To my astonishment, the floor was dry! So I thought, "Okay, I'll repeat my warm-up drive and see what happens". What happened? NOTHING! No runs, no drips, no errors.
I think that my car "knows" that I had ordered a new radiator, and it was "behaving itself" - trying to lull me into a false sense of security. Little does it know, the new rad will be here by Thursday and we'll see who's BOSS!
Our cars must be related. I have had similar things happen more times than I can count.
New rad is in and already I can tell the difference; 15WHP increase, valve lash has reset to optimal on all cylinders (intake AND exhaust), I've gotten at least 1/32" of new tread on all tires and my ED has vanished!
But seriously, the swap went great and I no longer am worried about a catastrophic failure at the least suitable time. I might even go to AMP on 8/12 to test it out (and find a new failure point).
One step closer to EFR glory! Installed ID1050x injectors yesterday. After setting Req Fuel and tweaking the dead-time numbers, the car started and idled perfectly. I just had to adjust the IAC slightly and there will be some tweaking of the VE table, but so far this has been the least eventful change made to the car by far.
Next on the "hit parade";
- DIY Autotune's "Max Spark" kit
- Change to a full-return fuel system
- Install the EFR
- Ride off to Valhalla
08-16-2018, 05:50 PM
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