Agreed.

I wish a fellow Oz person would go out and buy a motec.

Or even better go and get their hands on that car which supposedly had 25%+ gains that was discussed in that autospeed article.

 

I heard that car is now dead and in for MAJOR engine repairs - it turned out to be a VERY expense exercise.

 

UL and/or others:

Could you briefly explain blueprinting?

Thanks,
Mike

 

I've never blueprinted an engine but my understanding is it is a tolerance matching exercise.

Any production part (say a metal bearing or bushing) is made with a specified tolerance (say +/- 0.xxxx inches) since no manufacturing can hit an exact value each time. The tolerance is based on material choice and forming technique along with how much yield loss or rework expense a manufacturer is willing to accept. Some of these tolerances can be found in the shop manual.

So when you buy a car engine it is made up of parts that, hopefully, are all within size specification. That doesn't mean you won't have better results (less vibration, less friction) if you could put the engine together with tighter tolerances. To me, this is blueprinting, verifying tolerances are correct (often fixing wear items) and tightening what specs you can.

I don't know if shot-peening, for example, is also considered a blueprinting item?

 

Also the weights of some components are carefully checked; adjustments are made to ensure connecting rods are the same weight, that the crankshaft is balanced, etc.

 

I don't think shot-peening is consider part of blueprinting. To my understanding, shot-peening smoothing out your piston/walls ect... Its elimitated all the fine scratches on the metal wall. Imagine millions of very tiny hammers beating on your pistons to get a smooth surface.
nick

 

Pen and Prolene are right on.

Blueprinting, at its essence, is making sure the actual engine matches up perfectly with the specs. More specifically, since specs usually have a tolerance range as Pen pointed out, you're making sure they match up at the end of the tolerance range you want.

For example, if I'm building an engine for maximum power (not worried about long term durability) I'd do the following:

1. Choose the longest rods I could find out of the parts bin.
2. Choose the lightest pistons I could find, preferably with the biggest domes and smallest valve seat cutouts.
3. Set up bearing tolerances and ring gap on the loose end of the scale.
4. Make sure my valve job leaves the valves sitting as high on the seats as possible (valve recession reduces compression and can hurt flow in some cases).
5. Make sure all the rotating components are matched in weight and then carefully balance the bottom end.

The difference between an average production and one that is blueprinted with cherry picked parts (which are sometimes hard to get, but also why factories can build ringer cars with stock parts, they have huge parts bins to work with) could be on the order of 5-10% hp depending on the tolerances allowed.

UL

 

I can't see any reason that the rev limiter is harmful to the engine. What would make you say this?

 

[QUOTE]Originally posted by jguerdat
[B]

I can't see any reason that the rev limiter is harmful to the engine.

 

Thanks to all who have replied about blueprinting. Makes perfect sense now!

Mike