Hello,

im trying to rebuild sierra cosworth engine. My block is 205, Head from 4x4. im trying to reach goal of having 400 hp.
I have green injectors and standart 4x4 turbo what was rebuilded.

Im need to change head cam's, should i use oem ones, or take some aftermarkets?
What best head gasket and head bolts to use?

What other mods you advice me to do, because engine is in the rebuilding stage..... so want to do some mods then to get reliable 400hp

 

My Cossie made 469bhp with just a twin scroll manifold, bigger injectors and a borg warner turbo. The engine was stock but did need a decent intercooler.

 

i have injectors dark green, are they capable?

 

I think they were common on 380bhp cars. I went for 1000cc as a future proof which was a good idea as my new engine is likely to be way more.

I think you should add a WRC style metal gasket to be safe too.

A good intercooler is a wise precaution and ideally a large bore down pipe and exhaust as they can be restrictive at 400bhp.

The expense comes in when you do away with the laggy old T35 / 38 turbos and go for something modern.

 

With dark greens, do you mean 803’s? Those are capable of 340-350 bhp. With Siemens 55’s you will be able to go over 400.

Turbo wise there are several options. A T34.63 will do close to 380-390, and a T36 and T38 should go over 400. But they will be very laggy. Another option is a GT3071 which is more modern so will be less laggy with good power. As said the Borg Warner EFR will be best but requires a special manifold.

Cams are not needed for 400. My preference would be a modern turbo, but in the end I chose a T34.48 as it meant I could have an off the shelf chip, which is a lot easier if you are in Europe and all the good tuners are in the UK.

 

My car made 425.6 bhp on a T34/63 turbo but it only lasted about 1500 miles over 8 months before the turbo needed to be replaced as at that power its pushed to its limit.

engine mods were standard bottom end with just pockets in the pistons, ported head and BD16 inlet cam. Standalone management system, hart inlet plenum and a good intercooler. 1050cc injectors

i wouldnt worry to much about the numbers and focus on the drivability as a well set up 350bhp will leave a badly set up 400bhp car standing if you can use all the power through the Rev range.

 

This is very true. I had a laggy setup before and the car made about 330 bhp but was not fast at all as was always off boost.