Cracked rocker cover 🤦‍♂️

[Smokey_1507]

Hi All, 

I decided to paint my rocker covers with a aerosol can I had for the last 6 months, I de greased and lightly sanded the bad spots then scotch brite all over, I then gave 2 coats of primer & let it dry, I then gave it two coats of Matt black & let theist dry, then put on two coats of watermelon megashift pearl and to finished I put two coats of lacquer, I was very happy with how they turned out considering it was done in my shed on a cold night with aerosol cans, 

I pulled the old pvc grommet and the two pipes from each head and put in An-10 adapters ready for the lines to go to the catch can, I cleaned the old sealant from the front and rear of the block and removed the 2 half moons as billet replacements and a head bolt kit to replace studs and washers.. 

on installing the half moons I put a healthy amount of sealer on and sat them in, I noticed that they don’t sit flush with the head, is that normal??

I put some sealer on the back portion of the head covering the half moon and along the front of the head.. I replaced gaskets with new ones just to be sure!! All was looking good at this stage.. 

but then .... 

As I was tightening the rocker cover studs my brother said that will do as moments earlier I said they only had to be hand tight, me being me I gave an extra turn and all CC I heard was “ding” I looked down and it was split 🤦‍♂️🤦‍♂️🤦‍♂️🤦‍♂️.. 

After a lot of swear words we walked away for an hour or two then I started the car to see if it would leak under pressure and surely it was 😭😭😭..  I noticed that it was leaking from the half moons at the rear too!!
 

I have sourced some rocker covers and will have to start again..  Any ideas why the half moons don’t sit flush and why the sealant didn’t seal & the rear of the head?? It did recommend 24 hrs but I’ve also heard people doing this job and driving straight away.. 

Any info ?? Did I miss something along the way??  

[hardsteppa]

Poor design? Rubber ones sit up a little bit like that cos they can squash flat. My Taarks aluminium ones sit flush.

[GTSBoy]

The cost of copy engineering instead of proper engineering.

[Ben C34]

I wouldn't be surprised if by "healthy amount of sealer" you put on way too much and that caused them to sit high

[r32-25t]

There and old saying, if it’s not broken then don’t fix it. Rubber ones have worked for years

[hardsteppa]

Yeah but if you ever order from efi solutions, get some of their aluminium ones. Only a few bucks, fit perfect, haven't had to touch them since were installed, and have had rockers off/on 4 times since then.

[Ben C34]

37 minutes ago, hardsteppa said:

Yeah but if you ever order from efi solutions, get some of their aluminium ones. Only a few bucks, fit perfect, haven't had to touch them since were installed, and have had rockers off/on 4 times since then.

How much sealant did you put on them?  A smear or a healthy amount....

[BK]

9 hours ago, Smokey_1507 said:

head bolt kit to replace studs and washers.. 

I assume you're referring to the rocker cover bolts. Was this one if those cheap shitty solid washer type kits that don't use a factory style rubber crush insulator ? If so, there is a reason the factory use these rubbers - to try and prevent overtightening.

Also the torque on these is only 2 - 4Nm.

Use the new factory stuff instead of the bling stuff - and actually torque them down in sequence. Not that this mattered in this situation with regards to sealing as the rear of your covers were kicked up by the billet half moons not being flush anyway.

[Smokey_1507]

5 hours ago, hardsteppa said:

Poor design? Rubber ones sit up a little bit like that cos they can squash flat. My Taarks aluminium ones sit flush.

I’m not sure, I purchased them from Franklin performance along with the head bolt kit 

[Smokey_1507]

3 hours ago, GTSBoy said:

The cost of copy engineering instead of proper engineering.

I may have to agree on this.. I will get some rubber half moons I think as said, as they can squash down. 

[hardsteppa]

2 hours ago, Ben C34 said:

How much sealant did you put on them?  A smear or a healthy amount....

I dont use sealant ben, i use my own various bodily fluids.

Wasnt tons, enough to give a little 'squeeze out the sides'.

[Smokey_1507]

3 hours ago, Ben C34 said:

I wouldn't be surprised if by "healthy amount of sealer" you put on way too much and that caused them to sit high

The sealer I used was like a liquid and came with a brush in the pot, I put a healthy amount on around the half moon to try get a good seal so it didn’t leak but the height wouldn’t be caused by the sealer imo.. 

[Smokey_1507]

52 minutes ago, BK said:

I assume you're referring to the rocker cover bolts. Was this one if those cheap shitty solid washer type kits that don't use a factory style rubber crush insulator ? If so, there is a reason the factory use these rubbers - to try and prevent overtightening.

Also the torque on these is only 2 - 4Nm.

Use the new factory stuff instead of the bling stuff - and actually torque them down in sequence. Not that this mattered in this situation with regards to sealing as the rear of your covers were kicked up by the billet half moons not being flush anyway.

I got the bolt kit from Franklin performance, they came with small washers but are not the crush type,, I will try get some new factory bolts from somewhere or re use the ones I took off.. cheers for the sequence! I did tighten from the middle to each end, I will make sure not to use a ratchet and only tighten by 🖐 once the replacement covers get delivered this week.

[Smokey_1507]

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[BK]

1 hour ago, Smokey_1507 said:

I’m not sure, I purchased them from Franklin performance along with the head bolt kit 

I have a set of Franklin engineering billet half moons here. Didn't end up installing them but I did place them for reference in an RB26 head when I was going to.

They sit flush.

[Smokey_1507]

I will check them again before the new covers go on.. would there be a difference in size for the rb25det and the neo motor in regard to the half moons?? 

[BK]

Yes, neo is different.

[Smokey_1507]

Ah that’s my problem then.. I have just noticed the gaskets are different too 🤦‍♂️ The neo ones have a flat edge where the normal rb are rounded.. I’ll use the old gasket as it seems to be in good condition. 

Ive changed all 6 spark plugs as the old ones were looking dirty

I have just bought some skyline r34 gt & gtt rb25neo genuine cylinder head half moons, 

just waiting on paint to be delivered then it can go back together,

cheers for all the help and info!!