Fook me....loud metallic ticking!!!!

[millhouse]

Well....as some of you may know I'm running a megasquirt as a standalone ecu to control both fuel and spark. I had the lower part of my VE table to the point where my afr was safe and reasonable. Today I decided to hook up the twins and start tuning my boosted portion of the VE table. Now...the boosted portion of my VE table is super rich...so I'm basically tuning it down to get closer to my desired AFR.

While doing some spirited freeway runs in boost....my engine suddenly started making a LOUD metallic ticking noise. At first I thought perhaps I blew out the copper rtv gasket, but not likely as it's a very thin layer. I was unable to check where exactly the noise is coming from as I stalled it when I was backing into my garage.

I could tell however it was coming from the driverside...and it increased with rpms and I do believe it changed pitch. My temperature increased after this noise started occuring...although it didn't go past ~ 215*F.

If you have any idea of things I should check once it cools back down (besides the exhaust) let me know.

 

[Daggar]

Sounds like it's time to pull valve covers at the very least. You might get lucky and see a broken or loose rocker or something. Better to have it "tink" then to "thunk" I think. Thunking usually means bottom end.

Good luck!

 

[millhouse]

Sounds like it's time to pull valve covers at the very least. You might get lucky and see a broken or loose rocker or something. Better to have it "tink" then to "thunk" I think. Thunking usually means bottom end.

Good luck!

I hear ya. It's odd though...my vacuum remains rock solid at idle and my rpms do vairy at all.

After I check the exhaust bolts to ensure everything is snug, the covers are definatly coming off.

I must say however that during the 1/2 hour I was tuning the boosted portions....it was WICKED!!! Even running conservative timing and a bit rich. It's showing 8 lbs of boost too!!! Well..it was fun while it lasted.

 

[65ShelbyClone]

At first I thought perhaps I blew out the copper rtv gasket, but not likely as it's a very thin layer.

RTV? Where did you use the silicone? I have never figured out how RTV could work in an area that gets so hot, but occasionally I see it squeezing out from the exhaust joints on DIY turbo cars. What kind of gasket do you have between the cylinder head and header? I'm not ruling out a BHG, but maybe it's something else.

I assume you also have a wideband?

 

[millhouse]

RTV? Where did you use the silicone? I have never figured out how RTV could work in an area that gets so hot, but occasionally I see it squeezing out from the exhaust joints on DIY turbo cars. What kind of gasket do you have between the cylinder head and header? I'm not ruling out a BHG, but maybe it's something else.

I assume you also have a wideband?

Because of the extra exhaust backpressure caused by the turbo's, my gasket choices are limited. Typically any type of paper gasket will not last very long on turbo appplications. If you have a clean/flat header flange and a clean/flat exhaust deck on your heads then copper rtv works great...and that's what I'm using.

As far as a wideband goes....yes I'm running one.

 

[65ShelbyClone]

I guess I can understand using silicone between the header and engine, but what about between the turbo and collector? That's an even more brutal area for heat and pressure. On my SVO, they came stock with no gasket between the manifold and head and a laminated stainless one between the turbo and manifold.......that was on top of all the grade 8 fasteners they used on the hot side. They need it too; a good couple miles at 14psi and the hot side will turn red.

 

[millhouse]

I guess I can understand using silicone between the header and engine, but what about between the turbo and collector? That's an even more brutal area for heat and pressure. On my SVO, they came stock with no gasket between the manifold and head and a laminated stainless one between the turbo and manifold.......that was on top of all the grade 8 fasteners they used on the hot side. They need it too; a good couple miles at 14psi and the hot side will turn red.

I have a stainless gasket between the turbo and header...although there are a few turbo kit manufacturers that preach using the copper rtv there too. The fasteners most defiantly need to be of a high grade (mine are grade 8 or better).

 

[Daggar]

So do you think that the ticking you're hearing is an exhaust pressure tick then?

 

[millhouse]

So do you think that the ticking you're hearing is an exhaust pressure tick then?

I have had exhaust tic's before…and they were nowhere near as loud, nor did they have the "metallic" sound to them. At this point I'm not ruling out anything…however I am somewhat expecting it to be a bit more "major".

 

[millhouse]

Well...I took the intake off and the drivers side valve cover. I went ahead and arched the solenoid over while I was up front and the valvetrain looked and sounded fine. I did notice however that while standing there I was getting huge bursts of air blown on my feet (wearing sandles). Soo...I did the only resonable thing and wedged my hand between the front primaries on the driverside, and holy hell!!!!

It appears that I've blown my headgasket between the compression chamber and the outside of the engine on number 5. After checking the plug it appears I was not detonating. I suspect that my early attempts at trying to seal my (then) gt40p heads is coming back to haunt me. I should never have attempted to o-ring the block to try to fix a problem caused by a weak head design (for blown app's). I'm thinking that perhaps my depth was a wee bit off on the o-ring on that cyl.

Argh, the fun never ends.

 

[Skoobie]

Time for a new block? That suuuuuuuucks

 

[millhouse]

Time for a new block? That suuuuuuuucks

Nah....I'm thinking of just ditching the copper o-ring and throwing a new gasket on her. That is...if there is enough material on the block to seal the firing ring on the gasket. If I find the o-ring is not at the proper depth I may try to fix it and throw another one in there.

My last resort will be to take my old 200k+ mile block and have it cleaned up...do a ring job, throw some new rod bolts & main bearings in and call it good. Ultimately a new R or Dart block is in my future....although I still need to buy a damn house before I go that far.

 

[Daggar]

Hell with it... clean up both surfaces as best as you possibly can. A very light sanding may also be in order. Slap a set of cometics on there and call it a day.

Oh... and be good to your tune.

 

[millhouse]

Hell with it... clean up both surfaces as best as you possibly can. A very light sanding may also be in order. Slap a set of cometics on there and call it a day.

Oh... and be good to your tune.

I hear ya. The heads were freshly surfaced before I installed em. I have a feeling my depth on my o-ring is off as my tune was safe and I'm running think deck aluminum heads and studs to boot.

I've heard good and bad about the cometics. When you get them to seal...they wont leak. Now....getting them to seal can be a bit tricky I hear. Also...once you get them to seal you better not detonate or else! Although, the same can be said about o-ringing the block...so I thought.

 

[Daggar]

I hear ya. The heads were freshly surfaced before I installed em. I have a feeling my depth on my o-ring is off as my tune was safe and I'm running think deck aluminum heads and studs to boot.

I've heard good and bad about the cometics. When you get them to seal...they wont leak. Now....getting them to seal can be a bit tricky I hear. Also...once you get them to seal you better not detonate or else!

All true