27 replies to this topic

[grumpy xu1]

I'm wondering if you have pollution heads & a non pollution intake manifold ? The edelbrock performer is very close in looks to the original 308 intake manifold. Check the heads 1st, but I'm fairly sure that the edelbrock intake manifold suits both heads, been a long time since I've seen 1 though.

[rodomo]

Blowing air = backfiring out of the carby?

[Shiney005]

The air that you are hearing will be being sucked in. Not blown out. A good little test of your inlet manifold gasket is to spray some Aerostart along the manifold edges, and if they are leaking you will hear the idle speed increase. If you have oil in you water it is probably also going the other way which is much worse and you don't want to be running it until it is fixed. As Gary said above, the Edelbrock Performer is a good dual plane manifold for a mild motor. As for the T piece, you can buy a brass one to screw into the manifold. If that is your hatch in your profile picture, then it looks to have come a long way. 

Edited by Shiney005, 17 March 2018 - 09:59 AM.

[Bigfella237]

So it sounds like you have pollution heads and if the centre bolts are stripped then the EGR ports are leaking, there's no other way air could be "blowing" out of an inlet manifold (on a N/A engine anyway).

 

Also it's common for these manifolds to corrode around the water jackets, which means pressurised coolant ends up in the sump, but if you have oil in the radiator then I'd say you have bigger problems. The only pressurised oil that gets to the cylinder heads in a Holden V8 is through the pushrods and there's no way that could find its way into the cooling system, so IF you do have oil in the radiator then it almost has to be a cracked block?

 

EDIT: Never mind, I obviously type too slow!

Edited by Bigfella237, 17 March 2018 - 02:40 PM.

[Bigfella237]

Looks like exhaust gas would be blowing straight up and out through that lower hole...

 

 

"Universal fitment" manifold versus not-universal fitment heads!

 

Either have those extra holes TIG'd up and the surfaces machined or swap manifolds? Do you have a photo of the coolant passages at either end of the manifold? If they're corroded you could have them built-up at the same time?

[Shiney005]

https://www.ebay.com...DYAAOSwB3BaO4la

[axistr]

Yep Bigfeller is right those heads look like blue motor heads and they have the heat risers in the centre. You need a suitable blue motor inlet manifold and correct gaskets. The common problem of water leaking into the valley is more often the rear water crossover passage, the gaskets leak or manifold leaking due to corrosion/pitting. Its also common for the rear to leak and water/coolant enters into the inlet ports.   

[Ice]

You must type slow took me ages to put photos on here!
 
No oil in the water..just water in the oil, not a lot compared to how much the radiator was down, only had a short run on last trip though
 
That hole has been capped and filled, not good photos sorry, coolant passages aren't corroded as manifold was checked before putting on as needed welding on the exhaust side (different place) and pressure checked by reputable business as we wanted to only do the job once
 
Going to replace the manifold as something just isnt right... just need to know which one to look for 

Edelbrock performer dual plane get one of these and your good to go

[mick_in_oz]

Come on guys, get your act together.

 

RED Pollution heads! Single bolt in the middle and a "U" shaped EGR port, Blue heads have two bolts in the middle and square shaped EGR port.

 

The comment about one of the three bolts hols perhaps letting the EGR leak is valid, BUT, it looks as though that hole isn't drilled, only the centre hole, so shouldn't be a problem.

 

I'd be looking more closely at the way the manifold fits the heads, you will have to sit the manifold on and try to measure the gap that the gasket normally fills, needs to be checked in each corner, and top and bottom at each corner. The point of this is to try to confirm if the angle of the manifold faces correctly matches the angle of the intake faces of the heads. As the heads are not original, the manifold is not original, and the manifold has had work and will have been machined, there is a very good chance one or both items are incorrect and do not match. The net result is that there could be less compression of the gasket at the lower edge of the face of the manifold, causing the gasket to leak over time, leading to the described air leak and also the water in the oil...

 

Personally, even if I measured a "bit" of a discrepancy, I'd be tempted to simply use some fresh gaskets spray with something like Holomar, and use some sort of silicon gasket sealer around the water jackets of the manifold, both sides of the gasket, and ALWAYS sparingly so it doesn't get somewhere it shouldn't be.

 

If the manifold measures up poorly to the heads, getting it remachined would be an option.  Even a new manifold should be checked for fit in the same manner in case the issue lies with the way the heads have been machined.

 

Is there a gap between the bottom of the manifold and block with the side gaskets sitting in place, and if so how much???

[axistr]

The photo of the inlet manifold above in bigfellers post look like a blue motor manifold, correct me if I am wrong. The blue motor manifold had 2 staggered bolt holes in the centre as pictured. The original 253 engine in my WB panno has a WR prefix and has the same hole shape and bolt paten.

 

Only have a photo of the top side and yep I painted it red but the bolt paten in the centre at the heat riser is the same.

 

 DSC_00201254.JPG   68.47K   1 downloads

 

 

[grumpy xu1]

I'm pretty sure that if you have the exhaust crossover in the heads, you need a intake manifold to suit, otherwise you get the exhausting noise you were talking about previously by memory. Might pay to replace the head gaskets as mentioned above too ! Cheap & easy in a torana.

[grumpy xu1]

So the performer manifold will not suit?

I can't remember, just check if you can get it with the exhaust crossover in it. It's like a "u" shape isn't it. Obviously in the middle section. I have a 253 gmh 2 barrell pollution manifold, but it's either HX or vb i can't remember, but it was on a red 253.

[grumpy xu1]

There's around 5 or 6 genuine gmh pollution 4 barrel intake manifold's for sale on gumtree atm. You should be able to find what you're looking for there ! Around $120

[mick_in_oz]

My take on the EGR port of that Manifold is that it is intended as a one size fits all, both Red and Blue Cylinder Heads, the EGR port is positioned what I see as offset as to suit both EGR Ports shapes.

 

As long as the gasket is of a type that covers everything it should seal fine. It should only need a regular red manifold gasket set.

 

The comment about using a straight edge and "seemed to be out a few mm on both sides" a few mm IS A HUGE AMOUNT, I'd get your straight edge again and do the same check, but also flip over the straight edge and recheck to see how much error is in your straight edge (I'm picturing a long steel rule) to see if some error has crept in due to the measuring procedure and tools available. I'd not expect to see any more than perhaps 0.1mm, twice that amount is fine, as a gasket is meant to take up irregularities in the surfaces of the mating parts. Really it should be almost zero due to it supposedly being machined after being welded.

[axistr]

Its been some time and my memory isn't as good as it was, but in the eighties there were many incidents with leaking V8 inlet manifolds when the blue motors were introduced. Even mechanics Holden dealership included come unstuck when they mistaking fitted red motor gaskets to blue motors. Spare parts places were just suppling Holden red motor V8 gasket which were different to the blue motor. Then owners seeking more performance from their 253 V8 decided to use the later Blue motor manifold on there red motors same problem of compatibility. Just thought this maybe the case here and should be closely inspected