C3 Race Car Build

[Forrest Gump]

Manifold off and with it resting on the valley wall with no gaskets there’s 15 thou gap between head and manifold so I’m guessing it’s not compressing the gasket. Will have to find someone to machine it.
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..It looks thin, but you still have a bed of rtv present on the valley so wouldn't that indicate manifold is fully compressing on the gaskets or the rtv would have been completely squeezed out of valley area? You would also be getting a lot of oil drawn into the intake ports.

I've never understood why the blue permaseal bit is only on one side of those gaskets. What about the other side!!

 

[stealthyflatfish]

Feel your pain brother, B4 stripping manifold off again and wasting them expensive fell pro's, think I might have just removed the bolts, given the manifold bolts a liberal coating of RTV and re torqed to one or two lbs more than what they were. Some of those bolt holes can break through to the waterways and suspect the water might just run up the threads and out the top, and the actual gasket/manifold might not have been the issue. What do you think ? others on here might have had the same issue. Just my way of thinking.

 

[Oneball]

..It looks thin, but you still have a bed of rtv present on the valley so wouldn't that indicate manifold is fully compressing on the gaskets or the rtv would have been completely squeezed out of valley area? You would also be getting a lot of oil drawn into the intake ports.

I've never understood why the blue permaseal bit is only on one side of those gaskets. What about the other side!!

you can see oil rising up the gaskets. It might be compressing the gasket somewhat but I don’t think the clearance is right. It to me is the most likely explanation

 

[Oneball]

Feel your pain brother, B4 stripping manifold off again and wasting them expensive fell pro's, think I might have just removed the bolts, given the manifold bolts a liberal coating of RTV and re torqed to one or two lbs more than what they were. Some of those bolt holes can break through to the waterways and suspect the water might just run up the threads and out the top, and the actual gasket/manifold might not have been the issue. What do you think ? others on here might have had the same issue. Just my way of thinking.

I checked them first. None of them go into the water way and they were all thread sealed when I assembled the engine as some do go into the valley.

 

[Roscobbc]

Problem with intake manifold is that torque settings are quite low (so additional tightening is perhaps not the best answer) - so, presuming heads are 'off the shelf' and new aftermarket items - and inlet manifold is also a new aftemarket item..........which is responsible - heads or inlet? - this is a potential issue too (in the opposite way) for those who have 'decked' blocks and 'skimmed' heads. Some might double-up on intake gaskets......as (presumably) intake and heads are new - are they 'square'?

 

[Oneball]

Problem with intake manifold is that torque settings are quite low (and additional tigtening is perhaps not the best answer) - so, presuming heads are 'off the shelf' and new aftermarket items - and inlet manifold is also a new aftemarket item..........which is responsible heads or inlet? - this is a potential issue too (in the opposite way) for those who have 'decked' blocks and 'skimmed' heads. Some might double-up on intake gaskets......

Nothing is actually new. Heads and block have been skimmed.

Looking further into it. With gaskets in place there’s over 60 thou clearance to the valley wall which is apparently what you want.

Ports align perfectly, so skimming anything won’t help that.

Bolt holes are somewhat out of centre so I think opening them up to provide clearance to the bolts is probably the first step. Everything else will be much more complex.

 

[Roscobbc]

The quality of some aftermarket inlet manifolds IMHO can be a little suspect at times - take off all that silver paint and you'll often see blow holes in the aluminium - perhaps machining quality needs to be questioned too?. We sometimes see relatively cheap SBC ally heads that are obviously manufactured in the far east that have failed from waterway corrosion - I'm guessing that far more components from leading American brands are actually manufactured in the far east than most people realise.........however I'm guessing that the standards required by most of these USA companies would be quite high (to retain market credibility) - whereas cheapo items off ebay and other sources has to be questionable.......

 

[Oneball]

That manifold is bare alloy. No paint on it. It’s also pretty old so I’m imagining Edlebrock were still making stuff in the USA in the 80s/90s

 

[johng]

Tim, how much did you skim off the heads and block? The holes in the head would move by this amount in the right direction to cause the misalignment you show. Opening up the holes sounds like a good first try.

 

[Oneball]

Tim, how much did you skim off the heads and block? The holes in the head would move by this amount in the right direction to cause the misalignment you show. Opening up the holes sounds like a good first try.

About 70 thou, inlet face was also skimmed from memory. There may be a correlation but the ports align.

 

[johng]

Might just be that the bolts holes used to line up and the ports didn't! There's probably enough space for the gasket to seal even if the ports weren't properly aligned. You might have inadvertently improved your gas flow Let's hope that opening up the holes does the trick.

 

[Forrest Gump]

Might just be that the bolts holes used to line up and the ports didn't! There's probably enough space for the gasket to seal even if the ports weren't properly aligned. You might have inadvertently improved your gas flow Let's hope that opening up the holes does the trick.

If.the bolts are going in to begin with then you’ll be okay because the hole clearance will effectively increase as the manifold pulls down. If they were tight against the other (upper) edge of the hole that would be a problem as bolts would bind as manifold pulls down - stopping it pulling down.

I reckon you just got unlucky with the RTV seal around the water ports - give it a bigger smear of Rtv!

The installation notes for my AFR heads advises applying RTV along the lower edge of the intake ports as well as of around the water ports.

 

[Oneball]

Unlucky would have been one leak. But all 4 water ports were leaking so not convinced. I’ve opened the holes up so we’ll see when I get some new gaskets. I’m also going to use some stronger washers.

 

[Oneball]

Manifold back on. Fingers crossed

 

[Oneball]

Up and running again, water pump bolt that was leaking has been thread sealed and is still leaking though.

 

[Nick B]

 

[Roscobbc]

Not sure if there are similarities with SB and BB waterpumps - but I notice on your image that the water pump bolts appear similar to a BB - certainly one shorter bolt as the BB. There is a risk that if one of the longer bolts is incorrectly inserted in the 'short bolt' hole and tightened 'enthusiasticly' it can bottom-out in the 'blind' tapped hole in the block, risking stripping-out the thread. That certainly happened to mine and a constant minor leak has frequently occurred. Not a critical amount of coolant would leak but as the gasket deteriorated with the coolant under pressure it would get worse. With the engine in situ I drilled-out the thread and used a Timesert kit with its helicoil like insert. Its not really strong enough to support a high grade ARP stainless bolt to any acceptable torque. All secure enough but even with plenty of suitable gasket material and doubling-up on gaskets it only worked for a limited time. Next step? - engine-out (yet gain) for either accurately boring-out the offending tapped hole, 'plugging' it and re-boring another thread? - don't think so. Problem is that the tapped holes are 'blind' - get it wrong and you're straight in to the waterway. Instead I chose instead of using a bolt - I used studding (and a nut) screwed in to the existing dodgy thread (chemically cleaned) with its Timesert and the use of some specialist Araldite epoxy as an additional fixative. A year or so later and (using double gaskets etc once more) its all holding togther and not leaking......

 

[johng]

So is the inlet manifold now sealed? Also, what happened with your brakes?

 

[Oneball]

Not sure if there are similarities with SB and BB waterpumps - but I notice on your image that the water pump bolts appear similar to a BB - certainly one shorter bolt as the BB. There is a risk that if one of the longer bolts is incorrectly inserted in the 'short bolt' hole and tightened 'enthusiasticly' it can bottom-out in the 'blind' tapped hole in the block, risking stripping-out the thread. That certainly happened to mine and a constant minor leak has frequently occurred. Not a critical amount of coolant would leak but as the gasket deteriorated with the coolant under pressure it would get worse. With the engine in situ I drilled-out the thread and used a Timesert kit with its helicoil like insert. Its not really strong enough to support a high grade ARP stainless bolt to any acceptable torque. All secure enough but even with plenty of suitable gasket material and doubling-up on gaskets it only worked for a limited time. Next step? - engine-out (yet gain) for either accurately boring-out the offending tapped hole, 'plugging' it and re-boring another thread? - don't think so. Problem is that the tapped holes are 'blind' - get it wrong and you're straight in to the waterway. Instead I chose instead of using a bolt - I used studding (and a nut) screwed in to the existing dodgy thread (chemically cleaned) with its Timesert and the use of some specialist Araldite epoxy as an additional fixative. A year or so later and (using double gaskets etc once more) its all holding togther and not leaking......

The one that’s leaking is the only one of the 4 that isn’t a blind hole, it’s goes into the water jacket. If it doesn’t settle will try a Loctite rather than a PTFE paste.

 

[Oneball]

So is the inlet manifold now sealed? Also, what happened with your brakes?

Don’t know, will see in the morning.
Servo has gone off to be checked.