engine building/internal work forum

Hey, this is probably a wrong forum but I couldnt find a better selection for my question...
Im building an engine (bmw s52) for turbo... now Im planing on doing as much work as I can myself for
1. financial reasons
2. its no fun having a car without actualy building it yourself ;)
back to my question...
Im looking for a forum where I could ask specific questions about engine rebuilding and engine related work. I read a few books on engine blueprinting and fi(maximum boost) but still have questions....

so far Im planing on using JE pistons to lower the cr to 8.5:1, port and polish, chromed crank/cam bearings, oversized valves, forged connecting rods.

Now Im planing on obtaining a cracked head to atempt porting it now 2 questions
1. good book writeup on porting, where to remove material and such
2. any way to check your work, measure the airflow without having to visit a shop everytime you make changes? I have 6 cylinders so I can try 6 different port profiles.....
3. how much does a airflow test cost?

Question number 2 conserning oversized valves and valve jobs in general
1. Is it possible to do on your own?
2. Whats involved in oversizing the valves? Boring the valves and recuting a new valve seats?

Any advice/comments would be great.
Tom

There is books on porting but for your car????? Next you can build a flowbench that works just as good as anything out there. If you get a scrap head to look at and test I suggest you cut it threw the intake and exhaust runners and look at how much meat you have to work with, and with the remaining ports flow them to the needs of your engine. Bigger isn't always the best, but proper flow is. Done right you'll see a big improvement.
My flow bench cost me...like $100, and I've been using it for many years.
As for oversize valves, that goes hand an hand with the flowing of the heads. Bigger valves without ports to match flow of the valves is useless and a waist of money and time.
You need to do some research on the project you have in mind.

Camshafts usually don't use any separate bearings. For the crankshaft you should go for high performance bearings from for example Vandervell. These are usually built up on several layes, the top leyer being of white metal (babbit).

To fit larger valves you must usually fit new larger valve seats (preferbly of beryllium-copper or similar), so this requires milling. You must also make the port size in the head larger so it fits with the larger inner seat diameter of the seats. One could also keep the stock seats and make the sealing area of the valve smaller but this reduces cooling and is probably not the best solution for a turbo engine.

How and where to remove material in a head to increase the flow isn't that easy, you should perhaps read some articles or books on the subject. However, I can mention that you usually removes material in the roof of the ports. Note that the BMW S52 engine is probably not one of the easiest engines to start with since it has a very good flow from stock (the risk is large that you just makes it worse). I don't know about the S52 but some of BMW Motorsports newer engines are CNC ported from the factory.

What a S52 engine needs most is probably con-rods, pistons, a better head gasket and a set of high strength bolts for mains and head. Then the engine should be fitted with a stainless exhaust manifold for a turbo (a really large turbo), an aftermarket ECU, intercooler, piping and perhaps a new intake manifold.

Since the S52 delivers about 300 hp, add a turbo large enough to deliver 2 bar of boost at peak power without being restrictive and you should have about 900 hp.

There is books on porting but for your car????? Next you can build a flowbench that works just as good as anything out there. If you get a scrap head to look at and test I suggest you cut it threw the intake and exhaust runners and look at how much meat you have to work with, and with the remaining ports flow them to the needs of your engine. Bigger isn't always the best, but proper flow is. Done right you'll see a big improvement.
My flow bench cost me...like $100, and I've been using it for many years.
As for oversize valves, that goes hand an hand with the flowing of the heads. Bigger valves without ports to match flow of the valves is useless and a waist of money and time.
You need to do some research on the project you have in mind.
Thanks for the response...

Research is a never-ending story :) When buying a cracked head i was gonna use the first cylinder part just to cut it then the rest for testing my work... How did you make a flow bench for $100?! ;) I found a site that a guy had a diy on a flow bench but it was more like $500.

Tom

Camshafts usually don't use any separate bearings. For the crankshaft you should go for high performance bearings from for example Vandervell. These are usually built up on several layes, the top leyer being of white metal (babbit).

To fit larger valves you must usually fit new larger valve seats (preferbly of beryllium-copper or similar), so this requires milling. You must also make the port size in the head larger so it fits with the larger inner seat diameter of the seats. One could also keep the stock seats and make the sealing area of the valve smaller but this reduces cooling and is probably not the best solution for a turbo engine.

How and where to remove material in a head to increase the flow isn't that easy, you should perhaps read some articles or books on the subject. However, I can mention that you usually removes material in the roof of the ports. Note that the BMW S52 engine is probably not one of the easiest engines to start with since it has a very good flow from stock (the risk is large that you just makes it worse). I don't know about the S52 but some of BMW Motorsports newer engines are CNC ported from the factory.

What a S52 engine needs most is probably con-rods, pistons, a better head gasket and a set of high strength bolts for mains and head. Then the engine should be fitted with a stainless exhaust manifold for a turbo (a really large turbo), an aftermarket ECU, intercooler, piping and perhaps a new intake manifold.

Since the S52 delivers about 300 hp, add a turbo large enough to deliver 2 bar of boost at peak power without being restrictive and you should have about 900 hp.
You`re right about the camshafts they dont have seperate bearing, what to say is that id chrome the cam surfaces where they touch the ledges to prevent them from wearing out so fast... they get scratched pretty easy for some reason...

I currently have 2 heads + another cracked one comming so Ill leave one stock then one will be ported... so even if I make it worst at least i can say I tried...

is anyone has any good book recomendations that would be great, I bought a few dvds on headwork and porting (standard abrasives)

for engine managment Im still not sure I guess its too early to tell... suposedly AEM has a nice EMS with boost control, water injection, traction control and many many features... but not yet PnP for the s52 other choice would be TEC3...



Tom

There are better solution than chrome, TiN or DLC for example. Note however that if you coat one surface, the other one might suffer from the wear. Usually you want one hard and one soft surface. For example DLC coated pistons pins have been used with con-rods running the rod directly on the pin without bearing.

DTA P8Pro is a cost effective solution for a EMS. It has 8 ignition- and 8 injector drivers. 6 of each are required for operating the BMW S52 sequentially. There are of course other systems but the price goes easily from a four figure to a five figure number (Bosch Motorsport, EFI Technology, TAG and Magneti Marelli has for example some nice systems, sadly they are expensive).

www.sdsefi.com has what looks to be a pretty good system. No expirience with it though. Good luck.

Ill look into systems but for now thats not my priority... can anyone point me to a writeup on how to make a simple bench flow?

Tom