How hard to build up a cossie engine?

[M K]

How hard is it to build up a cosworth engine???

I am at the stage of sorting my engine and getting it built up, I have the majority sorted and the only things left to get is oil pump, pistons, bearings and gaskets

But I am considering having a go putting it together myself!!! Should I attempt it or is it not worth the risk?

I am quite capable I like to think so should have no issues in that sense, just a bit daunting making your first ever build a 500bhp cossie engine but in reality it's only bolting stuff in and torquing it all up correctly

Any info appreciated

Thanks
Marc

[Carlo]

Going by the standard of your work mate I'm sure your unto the job

[Cochyn]

Seeing as you're good mates with and have had a previous built car by FMS, then I doubt you'll have any issues getting guidance. If in doubt, leave it to a pro, but your car deserves the best so wouldn't be skimping at this stage, not that your own work shows any of that anyway

[Paul Cos]

I'm doing mine at the moment. You need patience. I'm using the ford manual and just following it. Seems easy enough just take your time.

[Mark Barber]

easy mate we all here tohelp if you unsure

[cossiedavid]

as long as you know what piston to bore clearence,s have to be your be fine to tight and it will pinch up when you drive it hard then it will need a rebuild again

[M K]

When I have pistons it will be given to pmason engineering to be bored to suit said pistons

[M K]

Thanks for the info guys, think I will give it a go

[richyx]

the only thing im concerned about onengines is getting the correct bearing clearences, i still cant work out that plasti gauge lol

everything else is simple bolt on parts

[mallard man]

nothing simple about a 500bhp cossie engine. i see what goes into building and checking a build at Turbosystems.

[Simon T]

I've done a couple of engines, and i'm a graphic designer not a mechanic

Just keep everything clean and check everything twice

[grcossie]

I have build up a couple of Cosworth engines, adjusting the piston rings gap is a shit job

[DaveEsccos]

The secret to not only reliable but high output engine building is attention to the details and take your time over everything. Think about your ring gaps, plastigauging your crank / journal clearances. Having it all balanced by a reliable engineer, where to use loctite and where to use grease etc etc etc, you would be stunned at the things I get sent back with a note saying "don't know why this failed" when its painfully obvious.

[DaveEsccos]

I have build up a couple of Cosworth engines, adjusting the piston rings gap is a shit job

Were you using what we call OEM sizes?

For those who don't know, a YB bore size starts at 90.82mm where as say a Vauxhall XE starts at 86mm. When gapping rings, a good rule of thumb is say 0.0055 x bore diameter for the top ring and 0.0065 x bore diameter for the second.

On the example above, the XE engine is going to be much easier to gap the rings to because your dealing with round numbers. On the YB however, you have the odd .02 to allow for and it can be a pig to gap the rings for the inexperienced.

There are pistons and rings on the market for the YB which will follow what we term the OEM path:

90.82mm + 0.5mm over size = final bore of 91.32mm
90.82mm + 0.75mm over size = final bore of 91.57mm

And those that follow the much easier After market path:

90.82mm + 0.68mm over size = final bore of 91.5mm
90.82mm + 0.93mm over size = final bore of 91.75mm

Anyway, enough rambling. If any one wants more info let me know and I'll send you a PDF.

[Rolls]

Its probably the only job (along with setting up) that I'd enlist to a pro...