What caused my melted piston?

[Tomas Wallin]

I am only on page 4 of this huge post but that happend to me on a flat tappet cam. I am sure he must have a roller cam. I have since switched to a roller cam after blowing a hole in the piston from going lean. A cam lobe can definatly do some damage.

Yup, a hyd roller and the cam is running perfectly since I put it together again.

[WeaponX]

Pics of the last victims......#5 & 8

14lbs and 7000 rpm on 604 cid. The wrong fuel mix. Easy to fix this time just two new pistons and rings.Got lucky

Notice the eyebrows both missing the thin sides.

[Coolerman]

Pics of the last victims......#5 & 8

14lbs and 7000 rpm on 604 cid. The wrong fuel mix. Easy to fix this time just two new pistons and rings.Got lucky

Notice the eyebrows both missing the thin sides.

maybe it's the light, but in that 2nd pic, it looks like the block got torched. Also, I thought these motors were at 6lbs boost

[indywhsle]

I have not posted here much if at all but I just read every page and since I just had the same problem with my 502 with a m3 procharger putting out 730hp and 785fpt I figured that I would chime in. Mine had dyno time plus 4 or 5 hrs. and long story short it was the water pick up. I would recomend putting a low water pick up on the boat. Don't know if you already have one but that was never asked in any of the posts.

[WeaponX]

maybe it's the light, but in that 2nd pic, it looks like the block got torched. Also, I thought these motors were at 6lbs boost

Block is perfect. Burnt through the MLS gasket between 5&7 a little.

Lots of talk on these motors but the facts are 1063 hp at 6.8 psi on pump and 1186 hp at 12psi could get more out of it at both psi but I had just one day on the dyno only ran six pulls.

And it was the five days before the Shootout.

[Tomas Wallin]

I have not posted here much if at all but I just read every page and since I just had the same problem with my 502 with a m3 procharger putting out 730hp and 785fpt I figured that I would chime in. Mine had dyno time plus 4 or 5 hrs. and long story short it was the water pick up. I would recomend putting a low water pick up on the boat. Don't know if you already have one but that was never asked in any of the posts.

Actually I did put on a new dual design pickup (engine and IC) after this incident so the flow is better now but it should have been sufficient enough before as well. I know the flow through the intercooler is alot better with the new pickupdesign.

I use the drive water pickup for the drive oil cooler.

[DAREDEVIL]

Actually I did put on a new dual design pickup (engine and IC) after this incident so the flow is better now but it should have been sufficient enough before as well. I know the flow through the intercooler is alot better with the new pickupdesign.

I use the drive water pickup for the drive oil cooler.

PICS of the pickup ??

[2112]

Pics of the last victims......#5 & 8

14lbs and 7000 rpm on 604 cid. The wrong fuel mix. Easy to fix this time just two new pistons and rings.Got lucky

Notice the eyebrows both missing the thin sides.

How did you catch this? Just on tear down after a Dyno pull or was it in the boat already?
.

[WeaponX]

How did you catch this? Just on tear down after a Dyno pull or was it in the boat already?
.

After it ran. Just a bad guess on fuel blends. I saw a drop in power and boost and pulled out of it on a run for top speed. Got lucky on this one I've seen alot worse.

[Geronimo36]

After it ran. Just a bad guess on fuel blends. I saw a drop in power and boost and pulled out of it on a run for top speed. Got lucky on this one I've seen alot worse.

Yeah man, you got real lucky, that's cool!!

I kinda got lucky like that once... Had an engine pop the head gasket out in the 11 oclock position on #7. Blew the chunk of gasket into the lifter valley...

Luckilly the gasket was the weak link otherwise the piston would have been moments later!

[indywhsle]

Actually I did put on a new dual design pickup (engine and IC) after this incident so the flow is better now but it should have been sufficient enough before as well. I know the flow through the intercooler is alot better with the new pickupdesign.

I use the drive water pickup for the drive oil cooler.

I thought the same thing. $6000 later I'm not so sure.

[Tomas Wallin]

I thought the same thing. $6000 later I'm not so sure.

Here you can see the water flow at high speed.

[Geronimo36]

Here you can see the water flow at high speed.

Are you bleeding water off the rear corners of the cylinder heads?

If so, how big are the hoses?

[Tomas Wallin]

Are you bleeding water off the rear corners of the cylinder heads?

If so, how big are the hoses?

No I'm not.

How should that be plumbed?

I assume the bleed holes would be in the intake at the rear water runners in the heads, but where should the water be routed? Back to the engine somewhere or separate dumps?

[Geronimo36]

No I'm not.

How should that be plumbed?

I assume the bleed holes would be in the intake at the rear water runners in the heads, but where should the water be routed? Back to the engine somewhere or separate dumps?

You can do it a few different ways; 1. Route it to the front of the intake and "T" in with the hoses coming out of your intake (if you have plugs in the intake just use them), 2. Dump overboard, 3. Some guys have bungs welded on the tailpipes for the hoses to connect.

I'm using two #6 lines on either side of the intake which connect together via a "Y" connector that runs a single #6 overboard. If you have low water pressure you might want to tee in to the front of the intake or use smaller lines, possibly as small as 1/8". All you're doing is giving air pockets a place to escape.

I decided to dump overboard so I can peer over the side of the boat to make sure I'm pumping water at anytime.

I'd highly recommend doing it to relieve any air pockets in the heads (especially steel heads) to reduce the potential of detonation on the back cylinders.