R32 GTR RB26DETT

[Jjtxaz24]

Started doing a leak down test and decided  what the hell, let me take off the valve covers. Here's what I found:

A bolt snapped off:

And both together: 

 

So I still have my stock cams. I'm gonna take the bolt out and replace it. My end cap still seems good. Then toss the stock cams back in till I can replace them with better cams or just leave em stock. 

Any idea what the bolt PN is? 

[Duncan]

Umm yes that makes the problem pretty obvious, you have a couple of fouled spark plugs ?

[GTSBoy]

No wonder there were some odd noises.

[Duncan]

Cam cap bolt is 13058-56E00.

however....it's probably not that simple. #6 valves were closed when the pistons were going uppy downy. there is an oil feed all through there that will have shredded steel and aluminium in it, the cam's tunnel is probably damaged/worn etc etc

I would chuck a cam in, do an oil and filter change and see what happens but I don't like your chances

[Duncan]

Oh, also, why would 1 bolt snap and was it the cause or effect of an issue. Best reason for a bolt to snap is that it was over torqued which means every other cam bolt is suspect. I'd replace the set, ARP do aftermarket that may be cheaper than Nissan (not sure, I've never checked). Alternatively, if there was an oil feed problem to the back that could seize and therefore break the cam.

At least post up a pic of the journals under the broken cam.

[Jjtxaz24]

16 minutes ago, Duncan said:

Cam cap bolt is 13058-56E00.

however....it's probably not that simple. #6 valves were closed when the pistons were going uppy downy. there is an oil feed all through there that will have shredded steel and aluminium in it, the cam's tunnel is probably damaged/worn etc etc

I would chuck a cam in, do an oil and filter change and see what happens but I don't like your chances

I will put the stock cams in when I extract that broken bolt out. 

14 minutes ago, Duncan said:

Oh, also, why would 1 bolt snap and was it the cause or effect of an issue. Best reason for a bolt to snap is that it was over torqued which means every other cam bolt is suspect. I'd replace the set, ARP do aftermarket that may be cheaper than Nissan (not sure, I've never checked). Alternatively, if there was an oil feed problem to the back that could seize and therefore break the cam.

At least post up a pic of the journals under the broken cam.

I promise they were not over torqued. I triple checked em and went in torque sequence. I know for a fact they were at the torque spec they were supposed to be.

Let me take a picture of that for you. 

[Jjtxaz24]

 

I used as thin,paper clip and checked it I could rod the oil squirter and it slid in and out. How deep are they supposed to be? It did go in 25.5mm. I guess I can take off another cap end and check that one. 

[Jjtxaz24]

https://www.ramsheadservice.com.au/product/nissan-rb26-genuine-cam-cap-bolts-kit-nis001/

 

Is this a legit company out there in Australia? They seem to have OEM bolts for a good price, but it seems to good to be true sorta speak. 

[Old man 32 GTR]

When I did my head the shop upgraded the cam cap studs to Tomei items. Might be a good idea since one has let go. 
and yes, Rams head service are a reputable shop, they are the ones that serviced my head 

[Jjtxaz24]

1 hour ago, Old man 32 GTR said:

When I did my head the shop upgraded the cam cap studs to Tomei items. Might be a good idea since one has let go. 
and yes, Rams head service are a reputable shop, they are the ones that serviced my head 

I saw the tomei ones, but I didnt wanna spend that much on them and I feel OEM should be good enough. After talking to some friends and stressing over this I feel that one bolt may have been over torqued. 

We have a shop here in the USA and its know for having cheap "affordable" tools. I used a torque wrench I got from there. That is the only thing I can think of as to why that one bolt would snap near the head. 

I'm gonna order another torque wrench only this one I'm looking for is gonna be in inch lbs not foot lbs and hopefully have a better accuracy. The current one I had was a +/- 4% tolerance on the accuracy. 

[GTSBoy]

1 hour ago, Jjtxaz24 said:

+/- 4% tolerance

If true, then it wasn't responsible.

[Jjtxaz24]

1 hour ago, GTSBoy said:

If true, then it wasn't responsible.

Then the bolts were just old? Either way damage is done. Trying to prevent it from happening again.

So new OEM bolts and use a different torque wrench. I guess. 

[Duncan]

Well by eye the cam journals look OK which is good news. 

While you may have never overtorqued the bolts, you don't know what happened to it before you got it. It may well have had different cams at some stage over the last 30 years. That's why I'd replace all the bolts, OEM are fine if they are cheaper.

[Jjtxaz24]

1 hour ago, Duncan said:

Well by eye the cam journals look OK which is good news. 

While you may have never overtorqued the bolts, you don't know what happened to it before you got it. It may well have had different cams at some stage over the last 30 years. That's why I'd replace all the bolts, OEM are fine if they are cheaper.

I think slapping in the stock cams will get her up and running which makes me happy. 

My next question is what's the easiest way to get my cams off without taking all the front belts and accessories off. 

I read through a thread that said to ziptie the belt and cam gears up and slide the old cam out and new ones in. 

I'm assuming I'd have to loosen the timing belt tensioner and to reach that I have to take off the lower cover and pull off the balancer. 

[Jjtxaz24]

So as you guys know nothing's ever easy on this f**king car, started to try and take out the broken bolt and having no luck. I tried to center it with a punch as best as I could and drilled into it to use an EZ out and not going well. Ended up off center and I got frustrated so I stopped. 

In the event I end up f**king it up. Do you guys know the the thread pitch these bolts have. I think it's an M6 but unsure what pitch it has. 

Pre planning the next step. Have you all used a helicoil? 

[GTSBoy]

You would be well advised to get a mobile thread repair guy to come and do this for you. They do it by muscle memory alone without the risk of you completely cocking it up (which you have to acknowledge, is a substantial risk!!).

As to the pitch on the bolts....you have the other bolts right there. Just measure it with a vernier caliper. M6 is usually 1.0mm

[Jjtxaz24]

8 hours ago, GTSBoy said:

You would be well advised to get a mobile thread repair guy to come and do this for you. They do it by muscle memory alone without the risk of you completely cocking it up (which you have to acknowledge, is a substantial risk!!).

As to the pitch on the bolts....you have the other bolts right there. Just measure it with a vernier caliper. M6 is usually 1.0mm

I looked online in my area for a mobile thread repair guy cuz that was a great idea and I didn't find one. I'll make a call to a friend and maybe he can help me out. 

If it goes south, I think this kit will work. It's an M6 x 1.0 bolt. 

https://www.google.com/shopping/product/296852226159252192?q=m6+helicoil+kit&client=ms-android-verizon&biw=412&bih=718&tbs=vw:l,ss:44&sxsrf=ALeKk01qXpOSKB90LjEsZI0_MzuiZwJFwg:1589439191304&prds=epd:16865377650706785995,cdl:1,prmr:1,cs:1

[Jjtxaz24]

I made some calls and after a couple of days of trying to find someone local to do it for me I had no luck. 

I ended up using a dremel to flatten the previous progress I did (it was drilling kind offset),  and ended up ordering some reverse drill bits, then used the ez out previously and bolt came right out. 

I took my other bolt, and it screwed right in and was able to torque it down.

Heres a pic of the bolt that's snapped with a regular one:

I tried to line them up as best as possible. The threads seem good on the head so I dont think I need the helicoil kit (I'm still waiting on bolts and I did order the helicoil kit just in case). The manual says to use 6.7-8.7 ft lbs of torque and I think the first time I did it around 8 ft lbs. I'm gonna be doing it around 7lbs maybe 7.5lbs to allow for that +/- 4% variable.

What you guys think? I'll be going back to my OEM cams.