20v turbo engine building

Hey all,

I'm in the process of building my coupe's 20v turbo engine and wanted to ask if anybody has any tips or things to remember when putting it all back together, even the most basic and obvious stuff. Anything would be much appreciated as I am quite new to engine building and there are so many things to remember as is.

Forged pistons and rods are on the way, I also have a custom tubular exhaust manifold with a 44mm Tial external wastegate and 3 inch Downpipe coming. The manifold will be built to fit a Garrett GTX3076R Gen II turbo with v-band connection, which is also on the way.

I will try to use a megasquirt MS3X as the ECU with a custom wiring harness. I am planning on ordering bosch 1000cc EV14 injectors and still have to get an uprated fuel pump as well. I have also ordered colombo & bariani camshafts and am looking to increase the rpm limiter to 8000. This begs the question, does anyone know what the limits of the stock valve springs are? At what rpm would one start to experience valve float? I've read that some have gone as far as 8250 or more. I'd love to hear any thoughts on this.

Also, if there are any other internals to renew at this stage I would appreciate any suggestions. Obviously I already have new connecting rod bearings, main crankshaft bearings and new cylinder head bolts. I will also be getting a new water pump, new tensioners & belts etc. This reminds me, has anyone gotten their hands on a kevlar or otherwise strengthened timing belt for the 20v turbo? I've tried contacting multiple gates racing timing belt suppliers but have had no luck.

I also already have a front mounted Intercooler and an uprated radiator, however I am concerned about the stock oil cooler. Are there any upgrades for the stock one or has it been efficient enough for others who have taken the coupe out on track?

I will be sending everything to the machine shop for porting, cleaning, balancing etc. probably next month assuming all the necessary parts have arrived by then.

Again, any and all advice is appreciated, thanks.

Hi,
Suggest you contact Joe @FCSS for advice in general, but I would look to purchase a new oil pump, albeit the price seems to vary a lot.

My comment would be to pay attention to the manifold, most of the aftermarket offerings have been/ are crap and worse than the OE upto 500 hp

Regarding rev limit, it seems that 8k is a safe threshold, and you may struggle to simply source OE alternatives.

Cheers Jamie

The oil pump is a good point, I remember actually reading contradicting opinions about it on some thread, some saying to simply clean it and do a 'health check' while some insisting it ought to be replaced while the engine is out. The price can be quite rough from what I remember, €500+ if I recall correctly which hurts a bit, but I suppose it's better safe than sorry.. it certainly is one of the last things you would want failing on you.

As for the manifold, this is exactly what I had read over the forums, although as my power goal is somewhere between 500-600 (which may be a bit optimistic) I definitely wanted to try to squeeze some more power from a hopefully more efficient manifold (38mm tubular ducts) and at the same time try to minimize boost creep with an external wastegate. This also allowed me to opt for a v-band connection for the bigger GTX3076R turbo I wanted. We'll see how it holds up.

I'll definitely have to try to contact FCSS, just checked their website and never heard of them till now.

Many thanks for the advice!