Blueprinting

[aussieg60]

Can someone explain what exactly is Blueprinting and is it worth doing ? What gets done in the process with what gains are to be made in doing this.

[h100vw]

Blueprinting involves building the closest engine you can to the factory std spec. Or using std components, build the best engine with ideal tolerances everywhere.

A great number of production car race series allow free suspension and brakes but insist on std engines. The only way to get ahead is to have a better engine than the rest.

A couple of examples of what the builder might do is get a batch of 40 pistons and measure them every which way dimensionally and then weigh them too. They would pick the 4 that are most closely matched. Then they would do the same for the con rods and compare the end to end weight to make sure that the engine is balanced in use.

A bit of honing of the bores so the piston fits perfectly and even taking into account expansion as the motor warms up. Matching the volumes of the combustion chambers is another one I nearly forgot.

Balancing and lightening of the crank and flywheel/clutch assembly would be obligatory.

To go to the n'th degree they would be looking at batches of injectors and maybe even try different ECUs to try and wring the last bit of power out of the engine.


Overall a very expensive project to undertake and for pretty modest gains of 10 to 15% tops.

Certainly you could build a much more powerful motor for less money but it would'nt be as smooth a runner.




http://www.lingenfelter.com/pack_fact.htm


Gavin

[aussieg60]

Thanks Gav, not many do this ? unless in the motor sport industry ?

Most engines these days are made with tight tolerences anyway ?

[aussieg60]

Gavin

I been reading about the Golf Limited. I was suprised to read that the engine is blueprinted.

Is there any difference in the G60 charger ? How could it pump out 22psi (1.5bar) ? :???: modified or rebuilt to handle the smaller spinning pulleys without grenading ?

[twin eng, twin turbs]

As an engine reconditioner your absolutely correct h100vw in the process of blue printing but their are some more processes caried out to ensure the best possible engine build.

Oil clearance of the reciprocating components is another, for example the crankshaft main and big end bearing jounals are measured for diameter and out of round. Then the block is fitted with its main bearings (numbered) and main caps and torqued up correctly, the main tunnel is measured for size and out of round. The same is done with the conrods, with bearings fitted (numbered) and torqued up and sizes checked. This enables the oil clearance to be determined by taking the main tunnel and conrod sizes away from the crankshaft sizes. Dependant upon the engine builder the oil clearances can then be matched to as close as 0.0001" (we still work in imperial) by linishing the crankshaft, or closing and honing the conrods and or tunnel boring the block.

Torque plates are also used when honing the block to ensure the bores are not out of round when the cylinder head is fitted. A torque plate is the equivalent of having the cylinder head fitted when honing as it is the same thickness as the head in relation to the length of the headstuds and torqued up to the same specs as the cylinder head.

Balancing is done to the to 0.1 of a gram both staticly for pistons and conrods (end to end) and dynamicly for pulley, cranksaft and flywheel clutch assembly in most cases at 500rpm.

i have done all this work on my own engines and the time it takes to do so is worth it for me, but to pay someone to do it could blow out the cost of the rebuild massively!

[h100vw]

Gavin

I been reading about the Golf Limited. I was suprised to read that the engine is blueprinted.

Is there any difference in the G60 charger ? How could it pump out 22psi (1.5bar) ? :???: modified or rebuilt to handle the smaller spinning pulleys without grenading ?

I don't see them doing 1.5 BAR mate. Except maybe in a motorsport environment. Obviously the 16V motor revs a good 1000 revs more than an 8V which may account for it????

Gavin

[gldgti]

the amount of boost you get from a supercharger is (basically) a simple relationship of volumetric displacements and rpm ratios. i don't know what the volumetric displacement per revolution of a g60 is, but if its more than 1litre/rev, i don't see why you couldn't have that much boost on a 1.8l engine. the g-lader chargers are good for over 15,000 rpm from memory (dont quote me), so that'll give you a max rpm ratio of say 2:1, but thats just as an example...

[aussieg60]

Is intake pressure different to what comes out of the charger ? In a number of articles it says 22.6 psi :?

Heres a few articles
http://www.dubforce.net/forums/index.php?act=attach&type=post&id=2780
http://www.dubforce.net/forums/index.php?act=attach&type=post&id=2774