Originally Posted by Tweak1
Hey guys haven't done much posting just a lot of reading I have a 92 TSi that I purchase about 6 months ago previous owner stated that the motor had been built. Now I decided to double check and nothing is like he said, cylinder 3 has a broken wrist pin and cylinder one at one time smacked a few valves around. So I have decided to build me a somewhat bullet proof motor. Few questions I have tho.
1. I'm in between Manley turbo tuff rods or GRP rods any recommendations?
2. What's a good valve spring/valve/ cam combo?
I'll have pictures up I'm at work right now when I get home I'll post them up any info is appreciated.
First off. I'd check the block to see that theres no scoring or any damage to the cylinder walls. If its too much damage, even with boring it out and honing might not be enough to fix it.
For the rods and valve spring/cam combo. A good place to start is seeing how much power you want to eventually put down to the wheels. I mean you could build a block thats capable of handling 1000hp, but it would be pointless if all your looking at is running in the 500hp range. The turbo tuff rods are very strong.
With the cams, you need to determine what size turbocharger you plan on running as well as what kind of port work your going to have done to the head, and what intake manifold (i.e stock and so on). The cams are really designed with different grinds to change their duration and lobe separation, which will help move your power band around to tweak your setup the way you want.
In reference to valve springs, thats also going to be determined on how big the cams are that you plan on running and how high you plan on allowing the engine to rev. For instance, you wouldn't wan't to put a spring with a lower spring rate on a bigger cam that your going to rev to 10,000 rpm. Spring rate is how much force it takes to move a spring a said named distance. For example, if you say a spring has a spring rate of 400lb per inch, it would take 400 lbs to compress the spring 1 inch. 100lbs to compress the same spring to .250 in, 200lbs to compress it .500 in, and 300lbs to compress it .750 in.
Any ideas on what your final goal is would be helpful to help determine what kind of build you should do
. Hope this helped a little bit. It also obviously gets a lot more in depth with all of the fore mentioned stuff listed, I am just trying to help you get the basics down to start the ideas flowing.