Torana SS

[vlad01]

Damn, I figured non OEM would be cheaper than KC, KC are wayyyy overpriced, so the after market billet style don't looks as bad price wise, but yeah, 250 is way too much either way.

For sure there would have been a few suppliers, large companies usually setup a few sources/contracts in case one goes down to avoid halting their entire product line if they were to only have one supplier.

[VK_3800]

Been chasing the cause of excess oil in the intake, to the point of fouling plugs. Second-guessing my PCV setup, leakdown tests...

Turns out some manufacturers can even get basic paper gaskets wrong... I've installed a lot of inlet gaskets, heck this engine has seen many sets, and I've never seen this happen. Both sides are very similar, they have torn apart even right around the bolt holes and the bolts were all still torqued up! I'm guessing a combination of oil and heat with unsuitable material?


Good thing I didn't just order two more sets of the exact same brand just hours before finding this... doh!

[immortality]

That sucks. Cancel the order?

[VK_3800]

Yeah hopefully, sent an email. Would be nice to find something this week as there's still an outside chance I might be able to drive it down to Kaikoura next weekend. Parts like this are suddenly drying up, for so many years you could walk in to almost any parts store and get most Holden parts off the shelf. Feels weird to need special orders and wait days or weeks (not to mention prices, oops I just did).

[immortality]

It certainly is becoming a headache getting Holden spare parts.

I actually keep gasket spares on the shelf for V6 stuff, I probably should start doing the same for the 304/8 as well.

My mate is putting together a 355 atm, he needs a oil pickup tube gasket and it looks like he'll need to buy a whole set to get one little gasket.

[brindo]

Thats a good find but frustrating - not a 10 minute fix.
Haven’t had that on intake gaskets but had very similar on gearbox input shaft bearing retainers. But that was using sealant and the gasket. Put it together dry and I didn’t have the issue.

[vlad01]

I'd had this sort of thing constantly with the thermostat gaskets, tried every brand, genuine too. All of them were permeable to the coolant through the material or just rotted to a mush.

I finally solved the issue, drum roll please... by using genuine gaskets. Yes that's right, using genuine ones where the genuine ones leak badly, but genuine ones also are 100% perfect. The difference is when the genuine ones were made, old stock= bad, new stock = perfect. I can not see any difference, identical looking material and manufacture's material part number prints, looks identical down to the fibres under a magnifier.

I can only conclude that either the manufacture changed the binder in the gasket to work with modern coolants, or it's exactly the same but age has caused the binder to chemically break down, but I would have thought the later should result in an appearance change if it's constituents are chemically altering with time. So I lean on the side that the manufacture has improved the formula to be compatible with newer coolant chemical standards compared to the old days.

One thing I did notice is the old stock has more compressibility over the new stock, when the bolts nip up, the torque wrench clicks off with bugger all turning, the older gaskets they compress some and the wrench clicks off after 2/3 to 3/4 turns, new is lucky to be a 1/4.

Took me years to figure out a gasket for the thermostat that didn't just turn to rotten mush and leak in 5 min or slowly weep out through the edge of the material. Often they looked like your intake gasket there.

That there is a classic material creeping/walking from heat or movement cycling. That is where one side of the material slides while the other is gripping but at certain parts of the cycle, expansion/contraction, loads etc... it reveres roll, so you end up with a net direction of the material travelling. I found this to be a given on brake pad backing shims on my cars, they walk out from the caliper/pad in short time straight into the rotor hat. Hence why I remove and toss the shims (better pedal feel too) I have seen this also happen with weather seals and strips, decals etc...

In electronics and computers, thermal paste and pads can creep out, for paste they call it the pump out effect and it is inevitable on all chips, just a matter of time. Caused by the surface topology changing back and forth with heat load cycles.

Going back to the gasket, a good gasket should bond to both surfaces and have enough internal give to flex back and forth in both Z height and sheering loads to maintain sealing as well as keeping the gasket from walking. I found graphite gaskets one of the best in this regard and MLS/SLS being the norm these days for modern cars where nearly nothing is touched for the life of the car, MLS works like mentions but SLS works good just because steel can't creep any more than the locating allows since it is so rigid and un-tearable.

[VK_3800]

Vlad, if you have a source of genuine gaskets for a 308 I'd be interested to hear it - those are long gone! Yes pretty clear what happened, just very unusual to see in this application - this is the first time I used this brand and won't be doing so again. I find coolant is normally worse than oil, I've definitely played that game with thermostat housing. I suspect in this case they simply made them for vehicles where the inlet is not exposed to oil then used the same material here without thinking about it. The fact that these didn't stick to the surfaces backs up that it was the wrong material too, normally there would be a lot of scraping involved to clean it up. Steel isn't available and not an option without proper surface prep (machining) but decent standard gaskets won't be a problem.

edit: and regarding sticking to the surfaces, you can see the red RTV has done its job fairly well around the coolant ports at the ends.

immortality, the oil pickup gasket can just be cut off a roll of oil-proof gasket paper which is still easy to get (I think), I generally keep some around for most items. A set of punches makes a much easier job of the bolt holes etc.

[immortality]

immortality, the oil pickup gasket can just be cut off a roll of oil-proof gasket paper which is still easy to get (I think), I generally keep some around for most items. A set of punches makes a much easier job of the bolt holes etc.

Yeah, I suggested the same thing to him.

[vlad01]

I can't help on the genuine gaskets for Holden v8, however Holden still sell some and continue to manufacture for the V6, although some are old stock or NLA, but the thermostat are being made still, hence why it took me a long time to figure out why a small lot of them sealed perfectly and stayed dry and leak free, while majority leaked day dot. Came down to me forgetting where I put my 15-20+ stash of gaskets I bought as NOS a few years ago from a closed dealer, then for me giving up and going to my closest dealer and buying one or two new thinking and seeing they were the exact same gaskets. Clearly more to this that I thought, the brand new stock clearly works as intended, old stock that has been sitting around def does not! The old stock ones I have are dated 2004 and as mentioned still the same manufacture and gasket material model (water mark type model number, brand, name etc...)

Of course I found the stash few months ago and I used them for my round of due maintenance and thermostat changes, only to find them all leak, where my white car was still perfect 6 months on, and that is where I started to realise I bought a single gasket from Holden for the white car when I couldn't find my lot I kept on hand.

I tried to get a few more new the week before to do the rest of the remaining cars and a friends car he left me to custom tune, they all worked leak and weep free!

My brother went through I think 3 sets of intake gaskets on his 304 over a span of 2 years, they all did the same thing as yours but on the coolant ports instead, some rotted, one just burst open but otherwise looked unaffected by the coolant. The last gasket he put in has remained leak free for quite a few years now. Was replaced before covid for sure. I can't recall what brand, but it may have been duropro or endurotec which was the two brands my local mechanic most often had available from his suppliers. But now it's usually platinum as that's all his suppliers have and they are crap.

Duropro it my preference for the V6, they make excellent graphite head gaskets with wider that stock fire rings, good quality build too. The paper gaskets in the kit is decent too.

There was a head or intake manufacture some years ago here in Aus that made supposedly the best intake gaskets for the holden v8, but I just searched and couldn't find it, I can't remember the name of them either. These gaskets had larger ID on the ports for ported heads and beads around all ports and bolt holes. It was touted by many as the best gasket to get. If anyone recalls who this mob was, post it up. The gaskets were made here, not overseas like other brands at the time.