is there anyone running gas rings what is it like

 

Do you mean like cooper rings, back in the day on the cosworth scene where a groove was machined into the block around each cylinder, and a length of welding wire was placed in the groove?

They still used a head gasket tho.

Bit old hat now with how technology has moved on imo.

 

RCM offers something of the sort I believe. I still see a few HUGE HP engines using type to tech.

 

I think bob rawl's car is running that system, take a look at his project thread, popular in the states too.

 

No bobs still running a head gasket I spoke to him about it yestaday

 

Pretty sure its still only available on the 2 litre block as it was used by the WRC cars

http://www.rogerclarkmotorsport.co.u...productID=1235

 

I think with the advent of MLS gaskets this is no longer a requirement or need. If there is not an MLS gasket available for your application and you had to use a fibre composite gasket then yes this would stop the fire ring from blowing out.

 

trying to make a 650 bhp engine as safe as i can .trying to fined someone running gas rings who is not trying to sale my some thing

 

every one tells me after 600 its a must

 

Like who? Quite a few are running over 600 with no gasket issues...

 

rcm for one mate

 

Firstly there is no such thing as a "reliable" 600bhp subaru engine as ultimately you're asking 150bhp per cylinder but thats not to say you wont get some decent use from it, secondly rcm maybe correct to some extent but even they had issues with the gobstopper and finally like I said previously the gas o ring conversion I believe is only available on the 2 litre engine.

 

Ive seen it on a dynoflash video on youtube, the guy points it out on a 2.5scd cosworth built engine he still uses mls head gaskets aswell i believe, his car makes 705whp with hta86 turbo, i dont know how reliable it was though

 

Compression ratio is a contributing factor to consider also, ultmately it's cylinder pressure that lifts the heads, not bhp numbers. For example I built a 2.1 scd/11mm arps at 9.0:1 cr, it was fine at 400bhp but heads lifted at 450bhp. I dropped it to 8.5:1 and it's fine at 450bhp now.

 

What fuel was it running on 9:0:1 comp?

 

Paul Doyle's car uses Cosworth head gaskets at 700 bhp plus nitrous without any HG problems. RCM are now producing a stopper gasket for the EJ22 and we'll be using those in the future.

 

V Power

 

Would it not be have been prudent to run better quality fuel when going for more power, as I read that high comp motors really come alive the better the fuel quality?

 

It is just a road car and the Customer wanted good spool and no more than 400bhp, hence high comp, when He took it for mapping they managed to get more out of it. That wasn't what I'd been asked to build the engine to though!
Yes race fuel makes a huge difference, typically on a rally car you gain around 30bhp and a alot more tourque. Once the extra timing is put in of course.

 

Typical Subaru owner chasing figures How much would a high comp 2.1 motor built to handle 550 cost roughly?

 

To quote for a long engine is difficult as there is alot to factor in depending on final spec, a 2.1 CDB short engine is approx £3500-£4000, you would need 14mm studs for that power and high(ish) cr.

 

As above Gas ring conversion is only available for 2.0L from RCM,I think someone from 22b tried to make Gas ring(O Ring conversion),not sure if they're done it or not

Mostly people running Cosworth Headgasket like we are run and they're been proven in many cars and many high powered cars,I would stay clear of the Cometic HG

Jura

 

Bit off topic, I take it water injection makes good power gains on an impreza with added ignition advance/active knock sensing too? Same as better fuel?

 

Hi there

We have run water methanol and with smallest jet and largest jet and consensus is we are gained with smallest jet around 15bhp and 30-40lb-ft over V-power alone on MDX321T,with largest jet on Rotated 30R we are not seen any difference


Jura

 

hi banny sti (Firstly there is no such thing as a "reliable" 600bhp)
i did not say a safe 600bhp what i said is (trying to make a 650 bhp engine as safe as i can)
i have been running my e/t engine with no h/g problems for some time @584

 

Good, I have a devils own kit in the garage, it will be going on my car

 

My rally car runs Cometic at 10.0:1 at1.6bar- 2.0 CDB with 14mm studs, no problems. I think that if the cr/boost is enough to lift the heads, the gasket won't make much difference anyway.
PS Cometic used to make the gaskets for Cosworth, I don't know who supplies them now, perhaps they are better? Ive not seen any real evidence to say they are though.

 

Be careful with the water injection, a water meth mix will definately give gains, but needs to be mapped for it. Just water on it's own can have negative results unless alot of time is spent on the dyno.

 

It's off my old golf that I had a v6 24v turbo in and a 2.0 16v turbo in, both mapped by me, v6 was 1.5 bar on an HX40 the 16v was 2.0 bar on an HX35, I find the WI makes a massive safety margin with regard to det, water on its own is more than enough (after all its the water that cools down the combustion temps). I thought with an impreza running such aggressive knock sensing that it would keep advancing timing and making more power until it knocks? AFR is not effected when running water, I've checked

 

In my experience water injection does affect AFR usually making it richer and mapping for it is important.