Cracked rear iron... I think

[ElTeeFauci]

So I just finished having a little bit of fun in the vert... datalogging and such. Saw a little bit of smoke, wondered if it was mine, so I went home.

Oil leak on the drivers side of the engine... sprayed it down with brake cleaner, started the engine. Nice stream coming from the coolant temp sensor that feeds the dash gauge. Obviously isnt coolant, so I'm guessing I cracked the iron.

Ben - I'm directing this at you (kinda). I googled the leak and up came a thread from the other forum where this happened. You replied saying you've never seen it. Now you have, twice!

I suppose when I get to CA I'll pull the engine and figure out whats going on.

[ElTeeFauci]

Maybe more likely a blown dowel o-ring.

[Rotary Evolution]

must have found an older thread, i've got a stack of cracked FC rear irons and even 20B irons with the old thin castings that cracked.

is this Junito?

if it is the iron did you feel any hesitations? it takes quite a bit more work to break the pinned engines but it is still possible. on the stock pins you can crack one without even feeling a hesitation.

[ElTeeFauci]

Nope. My name over there was midnfauciusn. Its coming from between the iron and plate about 1/2 inch above the coolant temp sender.

[ElTeeFauci]

No hesitations... actually runs as well as it ever has... just spews oil now. Probably about a pint per minute.

[Rotary Evolution]

ah ok, well i would clean off the dowel area just forward of the oil filter and just above the coolant temp sender. shine on the rounded part of the casting with a flashlight and look for hairline cracks.

with the amount of oil it's pumping out it sounds like a crack at the dowel pin, sorry.

consider a stud kit, the iron will also have to obviously be replaced. it can be salvaged either by studding the engine and welding the iron or running external oil feeds to the front and rear iron and blocking the upper pin oil passage but that's only really worth it on drag racing engines or on track racing builds.

the drift guys have been going through irons like a fat kid in a candy store so i'm going to have to push more real fixes on them instead of throwing them together on budgets and hoping for the best. just had a early B code 20B that cracked the front iron, center thick iron at the front AND the rear of it, studding the front worked but i only noticed the crack at the rear of the thick plate after the engine was running again, the superficial fix only last half a run around the track but the front held up fine(replaced the broken front iron with a reworked 13B-REW iron matched to cosmo 20B spec, repaired the cracked thick iron by welding it and reinforcing the front housing with tight tolerance 1/2" studs, the back half of the engine was not reinforced because we did not have time before the event after we found the crack at the rear section).

being that the 20B thick iron is NLA we have to work around it or he has to source a C-D code short block. external oiling would save the block from the scrapper, as i'm not sure even studding the engine with a cracked iron will keep it from failing again down the road.

at least that gives you an idea of options if you never want to deal with it again and it winds up being a faulty iron.

i will be making a titanium stud kit for the 13B in the near future, but the price will be slightly steeper than some other kits at about $400 for 6 full length studs(to fit an unmodified block or 1/2" which is more suitable for high HP applications and requires block reaming/rethreading, priced higher because titanium still isn't exactly cheap). titanium may not be as strong as some other alloys but it does have good corrosion resistance as well as tensile strength, in the conditions it has to survive in corrosion can weaken other alloys over time.

[Pete_89T2]

OP - are you absolutely sure its coming from the coolant temp sensor area and not somewhere above it? Reason I point this out is if the O-rings under the oil pedestal blow out, it will flow down, make a mess and possibly look like its coming from the area the coolant sensor bolts into the rear iron.

[ElTeeFauci]

Positive. I'm pretty familiar with the engine. Its clean as it is, but when I sprayed it down with brake cleaner, I had no doubt where it was coming from. Definitely not the pedestal. You can actually watch the oil flow out.

[Rotary Evolution]

and a leaky dowel seal or oil pedestal o-ring wouldn't leak that much without any prior notice. a loose filter that spun off some might but it would probably be worse.

o-rings don't just "blow out", they can leak and slowly ramp up but not an immediate "there one minute" problem.

[ElTeeFauci]

I'll shoot a video for you guys and throw it on youtube.

[Sephitrask]

sure you dont want to pull it and rebuild it before you leave Jax? we could make it happen with a quickness..

[ElTeeFauci]

I'd love to... but the move comes first... financially and otherwise. I just bought 3 major appliances this week for the new house. That didn't help.

[ElTeeFauci]

So, this thread is on pause for a couple months... until I do the teardown. Lots of pics will follow.

[Rotary Evolution]

i take it you did find a cracked dowel casting?

you can replace the iron without disassembling the whole engine but unless the engine was putting out over 350whp you should look into why it failed otherwise even if it is fixed it will fail again or other parts will fail along with it. for example, if the tune or pump is bad which caused the detonation that took out the iron and you stud the engine the seals will be next to go.

i'm also looking to moving the shop down to central florida, but on the west side near clearwater/tampa. but that is about a year from now.

[730RWHP12A]

the iron cracked for sure, either because of too much timing or a lean spot in the fuel map, possibly an injector going bad or even a clogged fuel filter.. find what caused the problem or it will crack again.. good luck with the move !