Discussion
Thanks, I will bear that in mind. This is another pic of the crack. Head has been at Grace Engine Developments and they have come back with "I wouldn't use that head for boost, you`d be flipping a coin every time you went out".
To be honest I don`t want to be constantly thinking when is my expensive engine going to fail. Again!
What`s everyone else's thoughts?
To be honest I don`t want to be constantly thinking when is my expensive engine going to fail. Again!
What`s everyone else's thoughts?
I've seen and used much worse on other brand heads with no problems.
But that isnt to say all other heads are the same. So really it's down to people with direct experience of cossie heads.
They might know better if the cracks run very deep, whether they are a problem, whether they can be repaired etc etc
Give someone like Harvey Gibbs a should at SCS Engines ?
But that isnt to say all other heads are the same. So really it's down to people with direct experience of cossie heads.
They might know better if the cracks run very deep, whether they are a problem, whether they can be repaired etc etc
Give someone like Harvey Gibbs a should at SCS Engines ?
If it's just the one then repair it, as long as you find someone who knows what they are doing then it should be ok.
The official line is that the hoop stress holding the seat in has been lost, this means in theory it could come loose, although like Stevie I've seen plenty running ok with cracks in them, you never know....
When the seats are put in the head is heated, the seat insert frozen and pressed in so it's a shrink fit, some of this tension has now been lost.
You need a good experienced welder with a big machine, the correct rod, head pre-heated and he needs to go in, get the job done and finish it quickly. You can't arse around heating the area up slowly with a small welder, too much of it goes into the rest of the head softening and possibly warping it, there will be lot of heat in there even if it's done quick.
Officially it then needs putting through a hardening treatment, but I think for that I would grind it close to size while it's hot and peen it before final finish and cuts are done.
Any good head guy and welder will know this.
The official line is that the hoop stress holding the seat in has been lost, this means in theory it could come loose, although like Stevie I've seen plenty running ok with cracks in them, you never know....
When the seats are put in the head is heated, the seat insert frozen and pressed in so it's a shrink fit, some of this tension has now been lost.
You need a good experienced welder with a big machine, the correct rod, head pre-heated and he needs to go in, get the job done and finish it quickly. You can't arse around heating the area up slowly with a small welder, too much of it goes into the rest of the head softening and possibly warping it, there will be lot of heat in there even if it's done quick.
Officially it then needs putting through a hardening treatment, but I think for that I would grind it close to size while it's hot and peen it before final finish and cuts are done.
Any good head guy and welder will know this.
As said, contact some of the big name Cossie people
Harvey at SCS, Mountune, Julian Godfrey
they would be able to tell you for sure, or repair if need be
Or I seen Frosty used this place for a massive repair a year or so ago albeit a 2v head
http://cylinderheadservices.com/
I'm sure many of the cylinder head specialists could work with it too.
I really cant imagine the head would be considered scrap because of that little crack
Just search youtube etc for videos about head repairs, you'll be amazed at the work that's done
Harvey at SCS, Mountune, Julian Godfrey
they would be able to tell you for sure, or repair if need be
Or I seen Frosty used this place for a massive repair a year or so ago albeit a 2v head
http://cylinderheadservices.com/
I'm sure many of the cylinder head specialists could work with it too.
I really cant imagine the head would be considered scrap because of that little crack
Just search youtube etc for videos about head repairs, you'll be amazed at the work that's done
stevieturbo said:
As said, contact some of the big name Cossie people
Harvey at SCS, Mountune, Julian Godfrey
they would be able to tell you for sure, or repair if need be
Or I seen Frosty used this place for a massive repair a year or so ago albeit a 2v head
http://cylinderheadservices.com/
I'm sure many of the cylinder head specialists could work with it too.
I really cant imagine the head would be considered scrap because of that little crack
Just search youtube etc for videos about head repairs, you'll be amazed at the work that's done
thanks Steve, have rung these guys and sent a few pics over. Waiting for a price Monday.Harvey at SCS, Mountune, Julian Godfrey
they would be able to tell you for sure, or repair if need be
Or I seen Frosty used this place for a massive repair a year or so ago albeit a 2v head
http://cylinderheadservices.com/
I'm sure many of the cylinder head specialists could work with it too.
I really cant imagine the head would be considered scrap because of that little crack
Just search youtube etc for videos about head repairs, you'll be amazed at the work that's done
If they can put valve seats in Red Victor I'm sure my car won't be too much of a problem.
A small update as not much progress been made. Decided not to fix the current 4x4 head as it was going to end up under 138mm head height. Would have been throwing £1200 at a head very much on its last legs. I have another 2wd head on 138.5mm which I will probably use. Bassett Down Balancing have been given a contract to balance electric motors so we have now given the job to Grace Engine Developments. James there has built some very powerful reliable Cosworth YB engines so feel in safe hands. We did talk about going mad and doing a 2.2 stroker with a Borg Warner twin scroll turbo and 600bhp but maybe slight overkill!
Looks like we are going to do a nice road engine circa 450bhp, maybe longer rods and custom cp Pistons. Probably going to go Link ecu. Have asked for the engine to be done by June but best laid plans and all that......
Looks like we are going to do a nice road engine circa 450bhp, maybe longer rods and custom cp Pistons. Probably going to go Link ecu. Have asked for the engine to be done by June but best laid plans and all that......
Small update time!
Bought an Airtec 100mm top feed intercooler which should sort the cooling side of things, just have to sort fitting it now! I suspect there will be some butchering of the nosecone.
I've gone a bit mad on spec as well.
Have gone Nicasil lined, long studded 200 block with billet crank caps, Carrillo long rods, Arrow standard stroke crank. I also have some Pistons that I'm not sure about using. They are JE forged with titanium nitride coated rings but are 9.5:1.
I'm going with a Borg Warner EFR7163 running 1.8 bar.
What is the consensus on a CR this high. The engine was designed to run HUGE torque on a 48mm restrictor (ex Rallycross) which of course I don't have to run. I will speak with JE about whether I can machine a little CR out of the Pistons perhaps to 8.5:1 and if I can't then will have to go custom Pistons.
Bought an Airtec 100mm top feed intercooler which should sort the cooling side of things, just have to sort fitting it now! I suspect there will be some butchering of the nosecone.
I've gone a bit mad on spec as well.
Have gone Nicasil lined, long studded 200 block with billet crank caps, Carrillo long rods, Arrow standard stroke crank. I also have some Pistons that I'm not sure about using. They are JE forged with titanium nitride coated rings but are 9.5:1.
I'm going with a Borg Warner EFR7163 running 1.8 bar.
What is the consensus on a CR this high. The engine was designed to run HUGE torque on a 48mm restrictor (ex Rallycross) which of course I don't have to run. I will speak with JE about whether I can machine a little CR out of the Pistons perhaps to 8.5:1 and if I can't then will have to go custom Pistons.
A lot of people are getting away with higher CR's these days, but if you're on pump fuel, and limited space for chargecooling and wanting to run a decent amount of boost, I'd still tread cautiously there.
In the region of 8.5:1 will give a huge safety margin for little trade off compared to 9.5:1
In the region of 8.5:1 will give a huge safety margin for little trade off compared to 9.5:1
I remember you saying you used a 10% methanol fuel mix in your car. Maybe I should run Shell Nitro and 10% methanol?
Seems a much easier way of doing it than plumbing in an unreliable injection system. Obviously I will have injector headroom to support.
It's going to be mapped on a Motec M400 but don't know who to use yet. possibly Dialynx.
Seems a much easier way of doing it than plumbing in an unreliable injection system. Obviously I will have injector headroom to support.
It's going to be mapped on a Motec M400 but don't know who to use yet. possibly Dialynx.
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