White smoke on deceleration...

[Supra]

I do believe you are correct Sir! :icon_bigg

I used the ARP studs to align the HG, 2 rivets removed and all throughly checked for clearance. I had two people help me with the head. Myself and one other lowered it while my GF aligned it with the studs. I've done this many times and never had a problem. I checked the front plate hieght verses the block to make sure the front plate wasn't raised. Trimmed the front plate gaskets with a new single edge razor. Heh, I actually remember doing a visual check from the sides to make sure the HG layers looked compressed. :cry: I still am doubtful of a BHG, but if it's a MHG installation problem, it has to be related to the copper spray.

Believe me, I'm cmopletely floored that there's a ANY problems...

 

[IJ.]

I lost a MHG using sealer

I suspect mine had let go earlier than I thought as this build runs much cooler under boost.

 

[Supra]

do the block test and a leakdown and see what that gets you....

OK, I finally did the compression / leakdown test. Here's the results after 1,500 miles on the motor:

Leakdown
#1 - 4% to PCV only
#2 - 5% to PCV only
#3 - 4% to PCV only
#4 - 5% to PCV only
#5 - 6% to PCV only
#6 - 5% to PCV only

Compression (first stroke/peak)
#1 - 100/180
#2 - 100/170
#3 - 105/175
#4 - 100/170
#5 - 100/180
#6 - 100/180

There was no sign of pressure whatsoever from the cooling, exhaust or intake. I removed the o2 sensor to listen @ the exhaust. The compression numbers are a bit varied but the motor is newer and the compression is quite good and high.

I assume this means either high cylinder pressure or heat is required to cause the problem??? What do you pros think? :icon_bigg

I want to toss this out too - I want to drive it to the Chicago 2006 meet August 10th-14th (or similar). The car is running perfect, aside from the minor smoke on decel only. I'd like to get the boost back up to 17psi and tune it to around 11:1 AFR. Safe to do or not?

 

[drjonez]

#s look good to me.....CRANK IT UP!

seriously, i'd keep an eye on it and just drive it....

 

[Supra]

#s look good to me.....CRANK IT UP!

seriously, i'd keep an eye on it and just drive it....

After every race I'll have to ask " Can you pull over so I can see what my supra just puked onto your hood?". :biglaugh: :biglaugh:

The compression numbers look OK to you? I was worried about the 2,3,4 dip to 170... That 175 in the middle helps I guess. When I was testing I thought for sure it was going to be 160 or less. :cry:

I should add that the motor sat for a week prior to testing and was therefore stone cold and cylinders dry during testing. I did the leak down first, then compression tested it. Also, the plugs looked reasonably good but with a soot ring around the lower ceramic. I had a NGK 7 heat range in there running ~15psi.

 

[MDCmotorsports]

Rich:
Like the good doctor said, run it. Also, did you check to make sure that there wasn't any pressure pushing back into the cooling chamber (rising coolant level into the radiator?)

If the turbo continues it habits, send it back to me. A piece of FOD (foriegn object debris) may have been sucked up and caused the the assembly to come out of balance. If you see no shaft play (radially or axially) then may I suggest going with a bigger air filter with more volume. Make sure it is of quality (ITG, K&n etc)

WE WANT YOU AT CHICAGO!

 

[Supra]

Rich:
Like the good doctor said, run it. Also, did you check to make sure that there wasn't any pressure pushing back into the cooling chamber (rising coolant level into the radiator?)

If the turbo continues it habits, send it back to me. A piece of FOD (foriegn object debris) may have been sucked up and caused the the assembly to come out of balance. If you see no shaft play (radially or axially) then may I suggest going with a bigger air filter with more volume. Make sure it is of quality (ITG, K&n etc)

WE WANT YOU AT CHICAGO!

*I* definietly want to run it!!! I needed to get some input. To me the results are saying that the problem is either a head crack that's expanding with heat/pressure, or a problem external to the cylinders (turbo, ???). I need to get this smoking problem resolved...

Radiator cap was off and I carefully topped it to the edge with water. There was absolutely no pressure to the radiator or else it would have pushed the water. I used 100PSI through a brand new snap-on tester and when it snapped onto the adapter. Under pressure, it was so silent that I was yelling @ the crickets to shut up so I could listen for air leaking. There was so little pressure escaping anywhere that I had to cap the valve cover and put my thumb on one of the PCV outlets to hear/feel air coming out. I put ducttape on the T-body opening to cover it 95% so i could hear/feel air escaping there. Every cylinder was set to TDC with a dial indicator + extension.

What do you mean by "it's habits"? I don't think it has exhibited anything I would call a habit, at least not in a negative sense. The turbo has always had a bit of play up and down, but it still has no play front to rear. The amount of play hasn't changed since new. Is it possible a seal in the turbo is leaking a bit? Because to be honest, I'm very happy with this particular turbo and I'd hate to possible hurt it. I'd be more than happy to send it in for a check up (after Chicago :biglaugh: ). If I plug one side of the coolant lines with a rubber cork, and put vaccum to the other side of the jacket, it should hold vaccuum right? I can probably arrange to try that...

YOu meanted the air cleaner earlier too. As far as the air cleaner... It's a new 8" long K&N w/ 4" attachment straight to the 4" turbo. When I did my "turbo coolant bypassed" run, there was nothing on the front of the turbo. No AFM, no nothing. With the turbo "open" and the turbo coolant bypassed the smoking problem was equal or worse, certainly not less.

Are you going to be at Chicago meet? If so, shoot me a cell # and I'll get in touch with you at the meet. I plan to do all activities - except I have to drive home (Rockford, IL) every night so I'll miss the late night stuff. :3d_frown:

 

[Supra]

Also, how do you change a title? I want to change blue to white since blue is not correct anymore.

 

[dbsupra90]

Also, how do you change a title? I want to change blue to white since blue is not correct anymore.

you have to have a mod change the title.

i'll be in chicago too and would be willing to give a hand if you need it.

dave

 

[Supra]

you have to have a mod change the title.

i'll be in chicago too and would be willing to give a hand if you need it.

dave

That's cool. I don't think Gwen will be able to go. IIRC, she will be flying to Maine that weekend and has to work prior.

 

[MDCmotorsports]

Rich I was thinking about something today.

What brand of oil, what weight, and how much oil pressure are you running?

 

[Supra]

Rich I was thinking about something today.

What brand of oil, what weight, and how much oil pressure are you running?

Breakin first 500 miles - Valvoline non-synthetic 30W
Currently 500-1500 miles - Castrol non-synthetic, 10-40W
Was planning to switch to synthetic after 2,500 miles

Oil pressure with shimmed pump is 12psi at idle, 35psi @ 2,300 and ~45psi @ 3,000+ I have the stock oil cooler, flushed throughly, lines replaced.

I know some synthetic oils burn white. Is that what you were thinking? :icon_bigg No odor, and no sooty bumper. It's like there's no problem, yet there it is... :3d_frown:

Friday night and Saturday morning is basically dedicated to tuning the car and getting boost back up to 17psi, 20+ if I can get some high octane fuel. I'm leaving the video camera at home this time - IJ/Jeff. :biglaugh:

 

[MDCmotorsports]

Well Im thinking about having a restrictor made for the turbo.

This is a very common practice on some of the v8 application turbos. Typically a turbo doesn't like to see over 40psi under decell.

 

[Supra]

Well Im thinking about having a restrictor made for the turbo.

This is a very common practice on some of the v8 application turbos. Typically a turbo doesn't like to see over 40psi under decell.

Oh, I see. I don't recall what my oil pressure looks like under decel but it would be a safe assumption that it's ~45psi or greater... My memory is that the oil pressure levels off at ~45psi @ >3,000RPM but wasn't specifically paying attention to that detail. I guess what I'm saying is that I don't honestly remember what the oil pressure is when running +4,500RPM under boost or decel. I should have the car back together tonight and will be able to make a note of the actual numbers.

 

[drjonez]

what size is your feed/drain for the turbo?

 

[Supra]

what size is your feed/drain for the turbo?

I knew that was coming next... :biglaugh:

AN-6 for the coolant.
AN-6 for the oil. ***EDIT oil feed is AN-4***
Something larger for the drain.... Sorry but don't know the actual size. :icon_conf

It's supposed to be the equivilent to this:
http://suprasport.com/product.asp?itemid=481&catid=216
...except mine has pretty Earl's fittings instead of hydraulic crimped lines.

 

[Supra]

http://www.supramania.com/forums/attachment.php?attachmentid=8336&stc=1&d=1153415074

 

[drjonez]

I knew that was coming next... :biglaugh:

AN-6 for the coolant.
AN-6 for the oil.
Something larger for the drain.... Sorry but don't know the actual size. :icon_conf

It's supposed to be the equivilent to this:
http://suprasport.com/product.asp?itemid=481&catid=216
...except mine has pretty Earl's fittings instead of hydraulic crimped lines.

no restrictor on the oil inlet? if not, then there's your problem. -6 is WAY too big for oil feed.....drop it to -4 or -3 or get a restrictor....

 

[drjonez]

http://www.supramania.com/forums/attachment.php?attachmentid=8336&stc=1&d=1153415074

oh, and NEVER run a fram oil filter....:3d_frown:

 

[Supra]

oh, and NEVER run a fram oil filter....:3d_frown:

LOL, I ran FRAM for the first filter change because I knew I was changing it out after 5 minutes of run time. It's NAPA / WIX now!!! (Unless you have a problem with Wix).