RSX Piston Meltdown

[RSX302]

From Fuel Injection Section - Rick's Tank's at the Race Track


What compression ratio were you running at? 103 degrees and 91 octane are all we have in Arizona!

302cu, 9.5cr, 10-12 psi Twin Turbo intercooled, 750hp @ 7500rpm. (2.5hp/cu)

My EGT's would hit 1400-1500 as I kept my foot into it.


The only way to lower my EGT's was by increasing timing. I would guess I'm transferring the heat into the cyl.(double edge sword, melt the turbo or melt the pistons)

I will bring CR down to around 8.5. I started at 7.5 (dished piston) and that was way too low. (lazy) 9.5 drove and performed great, but I think is too high for sustained road racing. We'll shoot for the middle.

https://static1.pt-content.com/images/noimg.gif

[Chad-1stGen]

Ouch. Are you able to throw a new set of pistons it it or are you going to disassemble and refresh the whole thing?

[RSX302]

Ouch. Are you able to throw a new set of pistons it it or are you going to disassemble and refresh the whole thing?

I will be disassembling and check everything with a fine tooth comb.

After pulling off the drivers side head, it got into #8 cyl as well.

Block looks ok, but my biggest concern at this moment is the heads. Started melting and some of the piston stuck to them. I'm hoping I can mill off .005-.010" and clean-up.

[CarlC]

What fuel to you run Ron?

[Vegas69]

Ouch, looks like we are both in the same boat. Mine is torn down to the bare block as of yesterday. I like this part of it probably the best.

[shmoov69]

that blows. Did it damage the cyl's?
1500 is hot, but it should be able to take it for short bursts shouldn't it? I know mine has taken that a bunch and even 1400 for long drives.....read LONG! Like one leg of the power tour long! (Had a bad timing issue)
Looks more like the rings butt ended and popped the top, kinda like detonation.

[RSX302]

What fuel to you run Ron?


I run Mobil 91 oct.

[RSX302]

Ouch, looks like we are both in the same boat. Mine is torn down to the bare block as of yesterday. I like this part of it probably the best.

What happened to your's?

[Vegas69]

Engine builder matched the wrong distributor gear with the cam. Ate up the bronze gear and all that debris went through the motor. 1500 miles later still getting particles. Bearings have debris embedded and pitted. Time for some upgrades. :1st:

[RSX302]

that blows. Did it damage the cyl's?
1500 is hot, but it should be able to take it for short bursts shouldn't it? I know mine has taken that a bunch and even 1400 for long drives.....read LONG! Like one leg of the power tour long! (Had a bad timing issue)
Looks more like the rings butt ended and popped the top, kinda like detonation.

I think I'm good on the block. Don't see any damage.

I've run a good while on this motor with 1400-1500 deg short runs. It probably would have lasted forever on the street. I think I amplified my problem when I increased my timing from 25 to 27 at WOT. Decreased my EGT's by 100 deg when I did this. (as it does during cuise mode when I increased) Even though I didn't hear detonation, I'm sure it was there. Boosted compression ratio is 13-14:1. Probably should have added 100 oct for the track day.

Do you know what your timing did when you had the high EGT's? (retard?)

I need to find out if these statments are true--would explain allot and fall in line with what I'm seeing.

Retard timing= reduces cylinder temps but increases EGT's
Advance timing= increases cylinder temp but reduces EGT's

[RSX302]

Engine builder matched the wrong distributor gear with the cam. Ate up the bronze gear and all that debris went through the motor. 1500 miles later still getting particles. Bearings have debris embedded and pitted. Time for some upgrades. :1st:

Damn--that bites!! He's gonna help with rebuild costs..yes?

[CarlC]

I agree with you Ron on the non-audible detonation. With that kind of power/CI ratio, boost pressure, and pump gas.....

Sorry, I don't have any good Ford parts.

[RSX302]

Retard timing= reduces cylinder temps but increases EGT's
Advance timing= increases cylinder temp but reduces EGT's


I read an article last night brousing the web that stated "doing nothing else but Retarding timing will increase EGT's"

Stands to reason if you increase timing, you will reduce EGT's.

So, burn up the turbo or burn the pistons--take your pick. If you run tube headers, only the coating will suffer.

[shmoov69]

Well, my egt's were high forever until I got a 6AL-2 box this spring. The best thing for the car by far! Before I had the timing advance locked at 24 with a 6A box. That made the cruise temps 1300+ normal. The time on the PT that it got so high was when it started in TX and it was running goofy so I checked the timing and it was off the mark. Bad! So I reset it and it drove to MO and ended up changing the P/S lines that night because the heat of 1400+ for about 5-6 hours cooked the lines. I also changed the pumpkin that night to a "beside the shed in a bucket" 2.70 gear that a friend had on the quick. I thought it was the gear ratio since I just changed it to a 3.70 that I had laying around because my 3.00 did not work that I had just changed earlier due to a bad locker that I got from someone on here.....but that is another story entirely, sorry I got off track there, ADD ya know! Lol
anyhoo, I thought the engine RPM was the problem so I changed that and was on our way the next AM and made it only about 3 hours away and lost an oil line to the turbos, at that piont I gave up and called for help and trailered it home. I let it sit for several weeks while I was discusted. I tell you all this story to say that when I got to work on it and get the engine washed off from the oil, I happened to look at the balancer and it just didn't look right so I reached down to wiggle it and it wiggled! Turns out that the balancer bolt came out and had ate up the front of the crank and the balancer. So, the timing "adjustment" that I made in TX only slowed the timing enough to cause the super high EGTs. Got a steel crank after that tho! Lol.

But yes, slower timing will cause higher EGTs and faster timing will cool the EGTs.....to a point and then it will go the other way.

Wow, 27* at wot seems a bit high to me on pump gas, but maybe Fords like more? Mine will only do 24-25 max at wot on pump gas before it gets into rattle.

[shmoov69]

Oh, I don't understand about burning up the turbos from fast timing. What am I missing here?

[RSX302]

Well, my egt's were high forever until I got a 6AL-2 box this spring. The best thing for the car by far! Before I had the timing advance locked at 24 with a 6A box. That made the cruise temps 1300+ normal. The time on the PT that it got so high was when it started in TX and it was running goofy so I checked the timing and it was off the mark. Bad! So I reset it and it drove to MO and ended up changing the P/S lines that night because the heat of 1400+ for about 5-6 hours cooked the lines. I also changed the pumpkin that night to a "beside the shed in a bucket" 2.70 gear that a friend had on the quick. I thought it was the gear ratio since I just changed it to a 3.70 that I had laying around because my 3.00 did not work that I had just changed earlier due to a bad locker that I got from someone on here.....but that is another story entirely, sorry I got off track there, ADD ya know! Lol
anyhoo, I thought the engine RPM was the problem so I changed that and was on our way the next AM and made it only about 3 hours away and lost an oil line to the turbos, at that piont I gave up and called for help and trailered it home. I let it sit for several weeks while I was discusted. I tell you all this story to say that when I got to work on it and get the engine washed off from the oil, I happened to look at the balancer and it just didn't look right so I reached down to wiggle it and it wiggled! Turns out that the balancer bolt came out and had ate up the front of the crank and the balancer. So, the timing "adjustment" that I made in TX only slowed the timing enough to cause the super high EGTs. Got a steel crank after that tho! Lol.

But yes, slower timing will cause higher EGTs and faster timing will cool the EGTs.....to a point and then it will go the other way.

Wow, 27* at wot seems a bit high to me on pump gas, but maybe Fords like more? Mine will only do 24-25 max at wot on pump gas before it gets into rattle.

Ok cool thanks..that fits to what I was thinking.

I originally had 25* at WOT and the EGT's would hit 1500-1550 on longer pulls. I though that this would burn up the turbos if I left it this way. I tried 26* and 27* and the EGT's came down with no sign of rattle or power loss. EGT's came down to 1400 at WOT. I was happier with that, but I guess I put more heat into the cylinder and killed the pistons in the process. I should have used 100oct for more protection.

I will rebuild with around 8.8:1 so I can stay on pump gas and hopefully keep the egt's at bay.

[shmoov69]

I Wonder what the EGTs are on an F1 car? I know that the turbos glow on a dyno when they runn them.
I wonder how hard it would be to "burn up" a turbo? Short of oil starvation that is. Granted, I do understand that their turbos are prolly a bit better than ours! Lol!

[John Wright]

I Wonder what the EGTs are on an F1 car? I know that the turbos glow on a dyno when they runn them.
I wonder how hard it would be to "burn up" a turbo? Short of oil starvation that is. Granted, I do understand that their turbos are prolly a bit better than ours! Lol!Wonder what rpms those bearings see in the F1 turbos...the engines themselves are whipping along upwards of 14K...

[Steve1968LS2]

I will be disassembling and check everything with a fine tooth comb.

After pulling off the drivers side head, it got into #8 cyl as well.

Block looks ok, but my biggest concern at this moment is the heads. Started melting and some of the piston stuck to them. I'm hoping I can mill off .005-.010" and clean-up.

I was going to offer to help, but then I remembered it was a ford engine.. lol

Hope you get it all sorted out easily.. I'm getting ready to pull Penny's engine for a new one two (bigger one)

[RSX302]

Newer F1 engines don't use turbos anymore. They are amazing still.

[RSX302]

I was going to offer to help, but then I remembered it was a ford engine.. lol

Hope you get it all sorted out easily.. I'm getting ready to pull Penny's engine for a new one two (bigger one)

THAT'S COLD! lol

It'll work itself out and I'll be tearing up the streets and chasing you down in no time.:drive:even with a Ford!

Bigger engine? LS with Cubes?

[mjoc1]

ZL1 with twin turbo's

Mike

[RSX302]

Pictures?

Do you run a EGT gauge?

[alnoe]

Ron

What were the ring gaps set at?

It looks like the rings may have butted and this caused the top of the piston to lift.

Do the spark plugs have any "pepper" on them?


If the engine did not detonate it could be the ring gaps were tight.

A "lot" of SBF factory piston engines (specifically from 5.0L engines that had factory forged pistons) have lasted a long time with 10-15# of boost, at least until the blocks split.

PM me if you want and I can give you some other things to possibly look for, or shoot me an email at [email protected].


Al

[shmoov69]

Ron

What were the ring gaps set at?

It looks like the rings may have butted and this caused the top of the piston to lift.



Al

That was exactly my first thought from the pic, tightly gapped hypers, but as long as the thing has ran before made me question my "first thought".

[RSX302]

Ron

What were the ring gaps set at?

It looks like the rings may have butted and this caused the top of the piston to lift.

Do the spark plugs have any "pepper" on them?


If the engine did not detonate it could be the ring gaps were tight.

A "lot" of SBF factory piston engines (specifically from 5.0L engines that had factory forged pistons) have lasted a long time with 10-15# of boost, at least until the blocks split.

PM me if you want and I can give you some other things to possibly look for, or shoot me an email at [email protected].


Al

Rings gapped at .022"

Pistons I'm running are CP 4017R forgings.

Couple spark plugs where melted down a little. All indicators lean to detonation.

Thanks for the input...

[RSX302]

Pulled the motor down Sunday and the cylinders and rod bearings all looks like new. I will order a new set of pistons, pins, rings and hone the cylinders for the new rings.

I'm thinking I will set up the new pistons with around 8.8 to 9.0:1 to help lower egt's a little. I think that should keep me safe with 91 oct fuel at 25 deg timing with around 1400 deg egt's.

Not sure what 0.5:1 compression reduction with get, but had I not increased my timing to 27 degrees, we may not have had this discussion. Maybe melted turbo instead?

I've read that turbo's are good to around 1500 and some race applications have seen 1600.

[John Wright]

Maybe pulling the compression by that 1/2 point may keep the pistons in there....what do you think about ceramic coatings for the piston tops?

[shmoov69]

You will gain alot more power with more boost than with more compression! Lol! Heck, drop it to 8:1!!!
Sound good, let us know when it is going again!


BTW- I've always LOVED your car!

[RSX302]

Maybe pulling the compression by that 1/2 point may keep the pistons in there....what do you think about ceramic coatings for the piston tops?

I had the ceramic coating and will be using it again. Maybe another reason to reduce compression a little more?

[RSX302]

You will gain alot more power with more boost than with more compression! Lol! Heck, drop it to 8:1!!!
Sound good, let us know when it is going again!


BTW- I've always LOVED your car!


I'm having second thoughts...I may run closer to 8.5. I wanted to run as much compression as possible to give good drivability on the street. 9.5 was very nice running. I hope 8.5 won't be too low. After all, I am cubically challanged. LOL

I can run the 10 psig spring at Willow Springs and 15 psig spring on the street and the drag strip.

[MonzaRacer]

here is another thing to think of http://www.turbomirage.com/water-alcohol-injection-parts-list.html.
Think of it all you need is a gallon of washer fluid (good old blue bubble gum stuff, dont think you need rain X in engine)and your golden.
Had a buddy with a 331 Ford and he put on some idiotic looking turbo setup (idiotic in the oil lines looked like they where duct taped and welds that could be done better by a 2 yr old) but his 11.7 to 1 engine needed help IMMEDIATELY even with 110 Cam 2/Turbo Blue race gas.
So I sent him this link, he ordered all the parts and plenty of different spray nozzles and after about 20 minutes of pissing his neighbors off he hit on which worked best.
Oh and he had to work out when the water injection needed to come on.
And all of it for way less than other he found.
Good luck.
Lee Abel
AFTERMARKET PERFORMANCE

[RSX302]

here is another thing to think of http://www.turbomirage.com/water-alcohol-injection-parts-list.html.
Think of it all you need is a gallon of washer fluid (good old blue bubble gum stuff, dont think you need rain X in engine)and your golden.
Had a buddy with a 331 Ford and he put on some idiotic looking turbo setup (idiotic in the oil lines looked like they where duct taped and welds that could be done better by a 2 yr old) but his 11.7 to 1 engine needed help IMMEDIATELY even with 110 Cam 2/Turbo Blue race gas.
So I sent him this link, he ordered all the parts and plenty of different spray nozzles and after about 20 minutes of pissing his neighbors off he hit on which worked best.
Oh and he had to work out when the water injection needed to come on.
And all of it for way less than other he found.
Good luck.
Lee Abel
AFTERMARKET PERFORMANCE

Yea..I've heard about water injection, but haven't worked with it.

I'm assuming water injection cools everything down to prevent melt down? reduction in HP too?

I guess even if one used high octane fuel, melt down can/will still happen. Just makes it harder for pre-ignition to occur right before the BIG melt.

[gmorris]

Water injection is great for additional safety factor but you do not want your tune to rely on it in case of system failure. Most guys will tune to the ragged edge without water/meth and then add it to give peace of mind. That way if it ever fails you won't garantee yourself a cooked engine.

[camcojb]

Yea..I've heard about water injection, but haven't worked with it.

I'm assuming water injection cools everything down to prevent melt down? reduction in HP too?

I guess even if one used high octane fuel, melt down can/will still happen. Just makes it harder for pre-ignition to occur right before the BIG melt.
no reduction in hp, actually an increase. Well, what I mean is the water or water/alky injection allows you to run more boost and timing than you could otherwise, hence the increased power. Straight water is the best heat absorber, but if you need additional fueling the popular mix is water with alcohol. This gives an octane boost and additional fuel (alky) to burn, also lowering your injector duty cycle with an efi setup.

It can be used simply as additional protection as above, using the same tune/boost as would be safe without it. Or it can be used to allow more boost and/or timing, getting power levels closer to running higher octane race gas without needing race gas. Many systems have a lot of built-in safety factors, but obviously damage could occur if the unit failed (rare but possible if properly installed).

Jody

[RSX302]

no reduction in hp, actually an increase. Well, what I mean is the water or water/alky injection allows you to run more boost and timing than you could otherwise, hence the increased power. Straight water is the best heat absorber, but if you need additional fueling the popular mix is water with alcohol. This gives an octane boost and additional fuel (alky) to burn, also lowering your injector duty cycle with an efi setup.

It can be used simply as additional protection as above, using the same tune/boost as would be safe without it. Or it can be used to allow more boost and/or timing, getting power levels closer to running higher octane race gas without needing race gas. Many systems have a lot of built-in safety factors, but obviously damage could occur if the unit failed (rare but possible if properly installed).

Jody

Very good...I see the purpose of water injection but since the damage is done, I will set up the motor so it will run all day on 91 oct with the proper egt's. I will give up a little hp but it should still be more then fun with 700+hp. My engine bay is very cramped as it is. There's something to be said about just having an engine.

[twinturbo69]

Ron,
How is the rebuild coming along? Glad to hear your block was okay!
My motor is almost complete: https://www.pro-touring.com/forum/showthread.php?t=62409
We swapped out the exhaust in favor of a cast iron manifold and have been porting it and waiting to get it coated with the extreme temp black coating.

Your story makes me want to run 100 octane for additional detonation insurance even though I have a 10 psi tune for 91 octane. I have no idea what my EGTs are going to be at, but they can't be any worse than they were with my old manifolds!

I wanted to hit you up regarding wheels for my car as I want a 335mm wide rear tire and am planning on the DSE minitub but had a few Q's.

Thanks,
Blake

[RSX302]

Ron,
How is the rebuild coming along? Glad to hear your block was okay!
My motor is almost complete: https://www.pro-touring.com/forum/showthread.php?t=62409
We swapped out the exhaust in favor of a cast iron manifold and have been porting it and waiting to get it coated with the extreme temp black coating.

Your story makes me want to run 100 octane for additional detonation insurance even though I have a 10 psi tune for 91 octane. I have no idea what my EGTs are going to be at, but they can't be any worse than they were with my old manifolds!

I wanted to hit you up regarding wheels for my car as I want a 335mm wide rear tire and am planning on the DSE minitub but had a few Q's.

Thanks,
Blake

Finally got the block back. All machined up and ready to go. Got the pistons (purdy) CP's Dished (15cc) with full coatings.

Next on the list is figuring out what rings I want to go with. Thinking steel Hellfire's at this point.

Hoping by next month we will be all back together.


Your 8:1 should be no problem with 10-12psi intercooled boost on 91oct and your EGT's should be fine. I just put to much timing in (27) with 9:1 and 91oct. Shoulda stayed with 24deg.(25 max) I wouldn't be rebuilding. max power is with 24Deg. Such as life..live and learn.

[Wicked]

I would monitor your intake and coolant temps on the long runs. Intercooler may be getting heat soaked.
What about the other cylinders? No damage? Are you monitoring individual EGTs?

I would also see if your tune has a timing modifier to pull timing when the intake and coolant temps go up.

I am a big supporter of more boost and less timing