RB26 Block cracked under intake manifold

[MoMnDadGTR]

Well i couldnt for any reason get a picture of what has happened to me but I'm back under the knife again. short lived dream haha. directly under roughly 5 and 4 piston, the block has cracked on the intake manifold side. i was wondering if anyone has experienced this on the intake side? i know they are known to crack between the water jackets on the exhaust side but this seems stange. strange things and me is very normal tho soooo...... JB weld the crap out of it or what mates? it is creating the car to over heat thats how this problem arose. i always noticed a tiny coolant leak in my garage from the very first time i started this motor. i took my intake manifold off and resealed it because i thought i was leaking on one of my coolant ports in my manifold... after some abuse the leak has gotten worse. the rad seems to pressurize extremely quick. i really dont care to much about this motor anymore do you mates think i will have luck with jb weld or something and let her settle then send?

 

 

Edited April 7, 2022 by MoMnDadGTR
cant type

[MoMnDadGTR]

it doesnt leak unless the rad pressurizes fyi. once i had the car back together i started it for 5 seconds then quickly jumped out and shut it off to see the leak/crack. doesnt take long to start dripping like a average bloody nose.

 

[Shoota_77]

Not having fixed one before my advice is invalid but if it was mine I would grind it back a bit with a die grinder and try and pack the JB Weld slightly into it a bit.  Let it dry, grind it back, squirt of paint and send it!

[GTSBoy]

With a crack on the inlet side, the block is so much more likely to fail on the other side if you push the power levels much. So.....just hold your breath.

[MoMnDadGTR]

On 07/04/2022 at 3:17 AM, GTSBoy said:

With a crack on the inlet side, the block is so much more likely to fail on the other side if you push the power levels much. So.....just hold your breath.

Got that right mate. Every time I start the car I hold my breathe. At first I thought it was my intake gasket so pulled that all off yesterday to do it again today to fix the crack. My rad seems to be pressurizing extemely quick is this normal? I started the car this morning from dead cold start for 4 seconds just to confirm the leak( needs a bit of pressure to leak) and my rad had pressure like mad after 4 seconds of running

[MoMnDadGTR]

No smoke out exhaust, compression is good, no oil on coolant or coolant in oil.

[MoMnDadGTR]

This was the smalll crack. I feel like this wasn’t my over heating issues tho.  It would over heat extremely fast and rad seemed to pressurize way to quick when trying to bleed...

[MoMnDadGTR]

maybe a small leak on the intake manifold as well where pressure was sneaking into the coolant system. i could hear a wierd sound i never heard before like it had individual throttle bodies naturally aspirated.  hard to describe the sound. like a deep waap sound that was never there ever. then followed by over heat. i think the leak was always there on block(crack). i ditched the metal intake gasket and went with a paper one with rtv on each side. gunna let everything sit till tomorow and try it again lol. what a shit show.

 

[MoMnDadGTR]

Lol

[Shoota_77]

First coat? 😁

Another 5 coats and she'll be good for 1000HP!  Cover the whole motor and you won't even need a block brace!

[GTSBoy]

Structural coatings are the best coatings.

[Predator1]

On 08/04/2022 at 12:03 AM, MoMnDadGTR said:

Got that right mate. Every time I start the car I hold my breathe. At first I thought it was my intake gasket so pulled that all off yesterday to do it again today to fix the crack. My rad seems to be pressurizing extemely quick is this normal? I started the car this morning from dead cold start for 4 seconds just to confirm the leak( needs a bit of pressure to leak) and my rad had pressure like mad after 4 seconds of running

Do you have a pressure sensor in the radiator?

[MoMnDadGTR]

On 08/04/2022 at 1:47 AM, Predator1 said:

Do you have a pressure sensor in the radiator?

No might not be a bad idea though mate.

[Ben C34]

Bummer mate.

This stuff is pretty amazing. Have used it to seal a radiator and a water pump on old bangers.

https://www.ebay.com.au/itm/SEALWEL-COOLING-SYSTEM-SEALER-CLEANER-SEALS-RADIATORS-HEADS-GASKETS-2xCUBES-/291625153239

 

i would be inclined to chuck some in.

[MoMnDadGTR]

On 08/04/2022 at 5:04 AM, Ben C34 said:

Bummer mate.

This stuff is pretty amazing. Have used it to seal a radiator and a water pump on old bangers.

https://www.ebay.com.au/itm/SEALWEL-COOLING-SYSTEM-SEALER-CLEANER-SEALS-RADIATORS-HEADS-GASKETS-2xCUBES-/291625153239

 

i would be inclined to chuck some in.

cheers chap. i ordered some but dont know if i can wait 2 weeks to try this bitch lol. shipping from australia takes some time these days for what ever reason. any where really about 2 weeks wait for me. 

 

[MoMnDadGTR]

im about 3 hours away from filling it up with fluid and trying it out again for the 73rd time. if it doesnt over heat or leak ill be happier than pig dung. if she over heats ill be pulling the plug on this engine and getting a prp rb30 i think, if its gunna go wrong it will for me hahah so i gotta go with something stronger. ive debating doing the jz swap a few times now...

 

[MoMnDadGTR]

well fired her up and the jb weld did its job great! only to force a bunch of coolant into cylinder 6 and 5.....so yeah im bunged for now and will confirm whats wrong. im guessing head gasket or cracked internally block. oh well.

 

[MoMnDadGTR]

i had so much coolant dripping from plug 5 and 6 i just put them back in and walked away

 

[Ben C34]

Damn.  That sucks man.

[Duncan]

sorry to hear that, it will be interesting to hear exactly what happened once you pull it down.

what was the history of they block? was it new to you, was it bored out?