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Bugger
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25,313 Posts
I just wanna know which head will add more bhp and won't crack. I was told and head bigger ported that the jcw with damage my engine.




Joe
Theres a fair few engines on that have done 30-40k+ miles on BVH's, Ben, Alski, Loui, Floof, Jove etc all did a lot of miles on their BVH's.
 

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Premium Member
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6,439 Posts
I just wanna know which head will add more bhp and won't crack. I was told and head bigger ported that the jcw with damage my engine.
This is probably the main underlying question. The r53 head has the most restriction at the exhaust so a modest increase on the intake and a much greater exhaust increase in exhaust is surely what we're after to balance the flow? Also with a ported intake and exhaust manifold so everything flows better would be the ultimate combo??
 

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Premium Member
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5,164 Posts
The cars that made the most over here for the past few years had RMW cylinder heads as far as i remember, ofcourse that doesn't mean that aren't other good options out there.
 

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Registered
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3,198 Posts
There were a few thousand converted cars , back in the day these were being sold by , mostly underpaid BMW techs and owners who demanded the original heads as they paid for a new one , £25 was the going rate as there were so many around - I snapped up loads , over a hundred , as they were bargain of the decade.
Most were used in BV head jobs , but I still have a few left , they are not like fish , so don't go off !
Now very rarely they come up on eBay etc
 

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Registered
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3,198 Posts
Aluminium comes in temper T0 to T6 , the higher the number the stronger it is , this is heat treatment , heating to a high temp around 500 degrees for a time and plunging into cold water , lower the temp , lower the T rating .
Then the aluminium is slow heated to around 160 degrees and cooled , this "ages" the material , it sort of locks in the strength , however once done if you heat again to 160 it unlocks the strength again .
This is where overheating engines knackers the head , constant heat cycles hot /cold also weaken the material and stress internally cause cracks
I'm not selling as bare head anymore , only as a ported and revalved £1000
 

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Premium Member
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5,164 Posts
I agree, this is a different case though. Also someone who's going to do this has to make sure he gill get back the same head, not an exchange.
 

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Cuntousaurus
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15,729 Posts
I've said it before, if you look around you can get this done cheap with great results. There are loads of top guys in the UK who know how to port heads. It terms of cracking heads, on a new head with good oil temp management and a decent tune you should not have this issue. Keep the boost modest or fit some anti det like water meth and this will also help.

In my experience:

- New head (well 3 miles or so if im honest) £70 (I bought two cores at this price and sold one to RMW!)
- Decent set of valves (G&S) and bits ~£300
- Head ported by a top UK guy (Ex F1/prodrive) £400.

A lot of other things were done at the same time including new pistons and the whole shebang built up by 1320 so difficult to isolate the increases but with just 14psi I'm making 20whp more than my old engine (stock head) that was running 18psi! Cooler temps + more power = WIN WIN :D
 

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Farmer boy!
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3,846 Posts
I've said it before, if you look around you can get this done cheap with great results. There are loads of top guys in the UK who know how to port heads. It terms of cracking heads, on a new head with good oil temp management and a decent tune you should not have this issue. Keep the boost modest or fit some anti det like water meth and this will also help.

In my experience:

- Brand new head £70 (I bought two cores at this price and sold one to RMW!)
- Decent set of valves (G&S) and bits ~£300
- Head ported by a top UK guy (Ex F1/prodrive) £400.

A lot of other things were done at the same time including new pistons and the whole shebang built up by 1320 so difficult to isolate the increases but with just 14psi I'm making 20whp more than my old engine (stock head) that was running 18psi! Cooler temps + more power = WIN WIN :D
So the suggestion i made is pretty much the best way to do it, what about rockers, is it worth upgrading them too?
 
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