Engine Blue Printing

green machine · Postby **green machine** » Mon Jun 16, 2008 11:47 am

Hoping someone can steer me in the right direction( no pun intended). The old girl has a few K's under the belt(and the MX5 as well). It is time for an engine rebuild but and while the engine was out i thought it would be an idea to blue print it. Has any one had their engine blue printed and if so who did you use. Any names in the South Eastern Suburbs. Thanks :roll:

Juffa · Postby **Juffa** » Mon Jun 16, 2008 11:57 am

green machine wrote:Hoping someone can steer me in the right direction( no pun intended). The old girl has a few K's under the belt(and the MX5 as well). It is time for an engine rebuild but and while the engine was out i thought it would be an idea to blue print it. Has any one had their engine blue printed and if so who did you use. Any names in the South Eastern Suburbs. Thanks

Welcome to the obession.

South Eastern Suburbs of which city?

Might also help to tell us more about which model MX-5 you have.

JH

green machine · Postby **green machine** » Mon Jun 16, 2008 12:28 pm

Dooo!!
Valid point. Melbourne. :oops:

AB7 · Postby **AB7** » Mon Jun 16, 2008 12:41 pm

Try Full tech (98887499), ask for Tony. He knows MX5 like no one else.

Blue94t · Postby **Blue94t** » Mon Jun 16, 2008 1:07 pm

Also give Nissco a call.
9761 4743
They do top quality work.
Jake

green machine · Postby **green machine** » Mon Jun 16, 2008 1:39 pm

Thanks Guy's. I plan to do some exhust mods at the same time. Keep you informed as it goes.
Cheers
AJ

Matty · Postby **Matty** » Mon Jun 16, 2008 2:15 pm

A 'full blueprint' of the sort done historically is kinda pointless, as the motors are infinitely better from the factory than those of yore.

Speak to Tony, he has rebuilt several motors with great success and knows a few tricks.

wun911 · Postby **wun911** » Tue Jun 17, 2008 10:22 am

Sorry nube questions here whats is blue printing? Does it give more performance?

Boags · Postby **Boags** » Tue Jun 17, 2008 10:55 am

wun911 wrote:Sorry nube questions here whats is blue printing? Does it give more performance?

With production line engines (historically, as Matty said) there has always been tiny overlaps of intake manifold ports and inlet ports in the head, as well as exhaust ports in the head and the exhaust manifold. These tiny overlaps do cause turbulence in the flow through the head; thus reducing flow.

Newer engines have much smaller overlaps due to better technology and better quality.

To blueprint is to match the ports exactly to one another so there is no little lips to cause turbulence.

I am wholly ready to be corrected on this; that is my understanding from talking amongst peers.

Boags

Matty · Postby **Matty** » Tue Jun 17, 2008 12:33 pm

That's one aspect of blueprinting.

The real key to it is to machine (or pick off the shelf) parts so they are at the (desirable) limit of the factory tolerances.

For example:
Bore the block to the largest tolerance.
Machine the block and head to the minimum height to increase compression ratio.
Pick pistons that fit with the minimum friction.
Open up bearing clearances to the maximum to reduce friction.
Pick pistons with the highest dome to maximise compression.
Pick rods and pistons that all weigh the same (ideally all weigh as little as possible too), so that the engine is balanced as finely as possible
Balance the rotating assembly of the crank, flywheel, clutch, etc to minimise power-absorbing vibration.
Shape the cam profile so the lift is maximised at all measured points.
etc...

Ultimately you end up with the optimum performance, whilst still keeping everything within the factory specifications (which is a 'legal' requirement for some forms of racing).

As I said, factory tolerances are much tighter than they used to be in the olden days, so the potential for gain is reduced.

Boags · Postby **Boags** » Tue Jun 17, 2008 12:36 pm

Thanks Matty.

wun911 · Postby **wun911** » Tue Jun 17, 2008 3:53 pm

I'm starting to understand now.

Oh man I would love to do this, sitting there weighing and measuring stuff all day long.

Benny · Postby **Benny** » Tue Jun 17, 2008 5:15 pm

Balancing the engine is far more important than blueprinting.

A nicely balanced engine is as smooth as silk, and wants to rev more and more.
Blueprinting can yield a small gain in power, but a well balanced engine will last longer than one that is just blueprinted and not balanced properly.

mekros · Postby **mekros** » Wed Jun 18, 2008 8:25 am

This is just taking the discussion to a semantic level....

wouldn't blueprinting mean that the engine is balanced to design specs, which would mean that the engine would do have minimal vibration? Or do you mean balancing the engine beyond design intent (and specs)?

Matty · Postby **Matty** » Wed Jun 18, 2008 2:28 pm

agreed. Any motor from the factory should (excepting manufacturing error) be built to the factory specifications - you could say this was manufactured to the blueprints (ie original drawings and specifications) if you want.

\"Blueprinting\" as the term is commonly used refers to using tighter tolerances than the factory spec, and/or optimising your choice within that tolerance band.

Out-of-balance (of the crank for example) would also be a factory defined parameter, with a (upper) tolerance limit. (That's why you see drill holes in the counterweights of the crank, and the edge of the flywheel.) But with some skill you could improve on the factory spec.