Cylinder Head upgrade

[piotr]

Hi guys .
what are the opinions on the “must “ when bringing the power up to the level around 500BHP in terms of cylinder head upgrades .
My friend who is a engine builder said the springs would be absolute minimum.Also he said it would be nice to go for one piece valves and port match .

im not too keen on taking the head off as the engine was fully rebuild in 2016 and only did about 5k miles but then again if it really needs doing then it needs doing and that’s it .
it would be nice to hear from people who actually are running cars with similar power level and what they did to the heads?

[SteveH]

You'll get that out of a standard head with standard valves and springs. Easy to lightly port and match the ports to the gaskets. If you go down the route of new valves, springs, retainers, etc it will get expensive quickly. Additional cooling channel behind the fire rings would be worthwhile to help manage temps.

[piotr]

You'll get that out of a standard head with standard valves and springs. Easy to lightly port and match the ports to the gaskets. If you go down the route of new valves, springs, retainers, etc it will get expensive quickly. Additional cooling channel behind the fire rings would be worthwhile to help manage temps.

Cheers Steve.
For me the main thing is reliability.
Kind of stupid to get lots of power if it will **** itself after 5 minutes.
What I’m worry about is that I will be asking 25 years old valves and springs to cope with more than twice as much power ,more heat and pressure.

[steve briance]

I can't offer any informed advice i'm afraid but am curious... What does your engine builder mean by one piece valves? Does he mean solid valve lifters?

Solid valve lifters seem to become desirable for higher rpm above 8000. If thats your expectation then, he could be right and that for me is also a reliability thing - no more ticking hydraulic lifters and no bouncing valves upsetting things at high rpms.

[piotr]

I can't offer any informed advice i'm afraid but am curious... What does your engine builder mean by one piece valves? Does he mean solid valve lifters?

Solid valve lifters seem to become desirable for higher rpm above 8000. If thats your expectation then, he could be right and that for me is also a reliability thing - no more ticking hydraulic lifters and no bouncing valves upsetting things are high rpms.

To be absolutely honest I’m not to sure what he did mean by that as we only had quick chat and I was working so didn’t go into the details.I have just assumed it’s different type of valves but I need to ask him questions .

[spink]

I guess by one piece he means non sodium filled valves?

[piotr]

I guess by one piece he means non sodium filled valves?

That’s what I think and I can see reading about it .
nothing to do with solid lifters .
I will have a chat with him after Christmas but I can see it coming,I will be taking head off as I don’t want to risk valve dropping

[mac2226]

Hi guys .
what are the opinions on the “must “ when bringing the power up to the level around 500BHP in terms of cylinder head upgrades .
My friend who is a engine builder said the springs would be absolute minimum.Also he said it would be nice to go for one piece valves and port match .

im not too keen on taking the head off as the engine was fully rebuild in 2016 and only did about 5k miles but then again if it really needs doing then it needs doing and that’s it .
it would be nice to hear from people who actually are running cars with similar power level and what they did to the heads?

If your going to remove the head then just change full head setup with supertec valves ti retainers double valve springs and port matching the intake and exaust if they’ve not been changed already the valve guides.

[Cordoba16vt]

I am in the 400+ BHP range with totally standard head, serviced, with one piece valves ( the original valves were not serviceable - they had sunk into the guides way too much and got thin at the skirts - 440 000km had taken its toll) having absolutely no issues to take the engine to 7000 plus rpm at 1.8 bar on billet RS2 and high lift cams. One thing I will do with next belt change is put the lightweight lifters from INA. Whatever the setup, if engine is taken regularly above 7000 rpm , especially for long periods, will cause reliability issues.

[s2dk]

I ran 565 hp on stock head and stock cams (aby)
only had arp head bolts and rs 2 head gasket
gtx35 gen 2 at 2.3 bar from 2018-2021
now I’m on regrind 7a cams same setup as above but only 2.15 bar and 642 hp

[nip]

I ran 565 hp on stock head and stock cams (aby)
only had arp head bolts and rs 2 head gasket
gtx35 gen 2 at 2.3 bar from 2018-2021
now I’m on regrind 7a cams same setup as above but only 2.15 bar and 642 hp

Hi there when did you get full boost before and after cheers

[s2dk]

Hi
I sadly don’t have a boost curve on the old setup
but I have a graph that shows both 565 and 642 and they are the same until 5500 ish

[nip]

Hi
I sadly don’t have a boost curve on the old setup
but I have a graph that shows both 565 and 642 and they are the same until 5500 ish

Thanks that will do cheers, bet it comes it alot harder now

[piotr]

I ran 565 hp on stock head and stock cams (aby)
only had arp head bolts and rs 2 head gasket
gtx35 gen 2 at 2.3 bar from 2018-2021
now I’m on regrind 7a cams same setup as above but only 2.15 bar and 642 hp

Many thanks for reply

[s2dk]

Thanks that will do cheers, bet it comes it alot harder now

Yah its Way different op top Thats for sure