Anyone got a link to a site or able to tell me anything more about blueprinting?

In engine blueprinting, all the specifications are double-checked. Usually this indicates closer-than-factory tolerances, with custom specifications appropriate for a street car or a race car. The goals usually are to:

Ensure the engine puts out the rated power (because not all mass-production engines put out the rated power) for its manufacturer's design
or

Make more power out of a given engine design, by extra careful measurement and assembly
balancing of reprocating parts and rotating assemblies, to reduce engine vibrations thus achieving more power due to recover of power "lost" to vibrations
Ideally, blueprinting is performed on components removed from the production line before normal balancing and finishing. If finished components are blueprinted, there is the risk that the further removal of material will weaken the component. However, lightening components is generally an advantage in itself provided balance and adequate strength are both maintained, and more precise machining will in general strengthen a part by removing stress points, so in many cases performance tuners are able to work with finished components.

For example, an engine manufacturer may list a piston ring end-gap specification of 0.003 to 0.005 inches for general use in a consumer automobile application. For an endurance racing engine which runs hot, a "blueprinted" specification of 0.00045 to 0.00050 may be desired. For a drag-racing engine which runs only in short bursts, a tighter 0.00035 to .00040 inch tolerance may be used instead. Thus "Blueprint" can mean tighter or looser clearances, depending on the goal.

Nicely put mate

Tp Blueprint is to take it to the original design specs,and that's it nothin' else.

iIs it true some engines come from the factory blue printed?, iv'e have read or heard somewhere that they r stamped this way!

I think the VR GTS-R (the yellow one with huge black bodykit) put out 300kw thanks to factory blueprinting by HSV.

you are trying to be funny....arnt u???

Darth some stuff like the FPV Fords and the HSV Crappydores have handbuilt stuff in them so yea basically taking it to design spec.
FNP there was a VS GTS Holden(i think) with 300kw but it was through cams and stuff besides being blueprinted.

Last edited by badcooky on Sun May 11, 2008 8:36 pm, edited 1 time in total.

a little more on what already been said.

ALL engine are already technicly blue printed. they are built to the original blue print IE:plans.

it's just that mass production demands that there be a tolerence factor.

when you see a spec given as 3thou to 5thou, in the facorty blue print it is 4thou +/- 1thou.

the problem starts when more then on reforence point is used and the second, third or forth point is found as a result of previous work.

you end up with whats called tolerence stacking.

if there are 5 machining operations to be performed and the tolerence for each is +/- 4thou and each operation is checked from the one befor it, you can end up with a 20thou difference from the first to the last. even though the tolerence is only 4thou.

Now we've all heard of the socalled 'freak engines' you know, those facorty built engine that just seem to out perform the others. The other end of the scale is the engine that just seem to get left behind by all the others.
chances are if you pull down each ot the two engines you find the freak fast engine will be almost spot on the factory blue print spec, and the slow engine will be on the border line of tolerence.


for street engine, machine back to factory blue print is all thats needed, and some times is overkill.

it all starts by closing and honing the main tunnel, as all other measurments will be taken from this. the block is the mounted on a jig (through the main tunnel) to the deck(s) trued. In the case of a V8 that means machining the decks 90degress from each other and square and level to the main tunnel. for and inline engine there is only one deck so square a level.
cam shaft tunnels get the same treatment if needed.
then check and correct any other mayjor points on the block

rods will be check for length, twist and bend and for big and little end bore sizes and weights, corrections will be made or rods junked.

the blue printing also incorperates and full ballance job.

ring gaps as mentioned will all be check and corrected. aplication and actual gap is irrelevent in a write up like this, as the prosess is still performed regardless.

crank shafts get indexing and stroke correction. (here is the time to deside if you want a few extra cubes by offset grinding to the smallest bearing size)

you can move onto blue printing cylinder heads aswell but that is story in its self.

jump on ebay or google pitstopbookshop
and find a copy of "The Step By Step Guide To Engine Blueprinting"

it goes through the entire process

There ya go.
Mass production and tooling wearing out is the enemy.
I thought there was blueprinting and balancing as separate but if ya think aboot it it's one process really.
Well done Tichster sixter.

thanks for the info! u answered my question.