Mk1 16v Project

[velly_16v_cab]

lol...very true.

[Preen59]

yea What's all this engine de-flashing about. i'd be interested to know all the things you're doiong to your eng, and the reasons why,. it seems a prettty comprehensive rebuild... (of the eng)

Well i figure do it once do it well so i'm not skimping on anything (i'm not spending money when i don't need to, either).

You know when you get a cheap injection moulded plastic part and there's little feathery bits hanging off it in spots? That's called flash. Its where the to mating halves of the mould (or sliding cores etc, but we'll keep it simple) don't seal together properly and the plastic 'squirts' out a little between the faces of the mould.

The same goes (basically) for a casting or forging. Where there are mating faces the can be flashing if the cast or forge die isn't perfect. In the cast it happens for a slightly different reason but we'll leave it alone because this thread isn't the place to be explaining the casting, forging and injection moulding process in detail.

Where you have flash, it can cause a weak spot and cracks/ failures always start from imperfections. Always. That's why you see Top Fuel engine rods are polished. So that there is nowhere for a failure to start, although that's not to say something will never fail.

So, by de-flashing the block and your rods, you eliminate a potential failure point.

The VW castings are very high quality, and the only spot on my block that needed de-flashing was the main bearing webs. The rest of the casting is perfect. Same goes for the rods, VW rods are very high quality and very minimal de-flashing is required, followed by shot peening.

Shot peening is basically sand blasting the rod. It uses glass beads. These glass beads remove the 'skin' of the metal and remove any surface stress and tension within the rod, making it tougher and less brittle.

Clear some things up?

[Preen59]

Oh i also removed all the welsh plugs from the block today. The small plugs in the ends of the block for the piston coolers i'll be tapping and fitting screw in plugs to.

Here's some before and after pics of the block from flash to deflash.



And after..



Can you see what i've done? You do it with a die grinder... And a steady hand .

[Jarred]

oh yea, I get that. makes sense. I'm geussing you'd have to be running a bit of a performance engine for any of the standard moldings to become an issue though right?


thanks for the explanation though. Handy bit of knowledge that i'll pull out at some point of time I'm sure.

[GoLfMan]

this is a very educational build mate, lovin ya work

[Preen59]

thanks for the explanation though. Handy bit of knowledge that i'll pull out at some point of time I'm sure.

Yeah, it's cool when like, you get to quote info and like, make yourself sound all smart n that..

[Preen59]

this is a very educational build mate, lovin ya work

That's what this forum is all about IMO. Sharing information about, and being able to discuss a common interest.

I'm happy to share the small amount of knowledge i have...

And if i don't know i'll make something up that sounds intelligent..

[GoLfMan]

That's what this forum is all about IMO. Sharing information about, and being able to discuss a common interest.

I'm happy to share the small amount of knowledge i have...

And if i don't know i'll make something up that sounds intelligent..

forums nowadays are headed toward less tech knowledge of the old timers and more about flashing and chipping cars which is a pity, love seeing a bit of the real stuff

[Preen59]

forums nowadays are headed toward less tech knowledge of the old timers and more about flashing and chipping cars which is a pity, love seeing a bit of the real stuff

Yeah, i'm not really a big fan of the 'purchased horsepower' thing. I mean, there is a market for it and i don't bag the people that take that route, but i'd rather do it myself and do it my own way. Much more satisfaction and much less cost.

I think being able to use the odd bolt on part is good, but not just buying everything and having it fitted by someone else so you can say you engine has all this brand name gear in it and quote horspower figures you should be getting, but not really knowing why or how those parts work.

[Preen59]

I'm geussing you'd have to be running a bit of a performance engine for any of the standard moldings to become an issue though right?

Sorry, forgot to answer your question.

Yeah, my block would be ok without doing it but it took 5 mins to do and if nothing else i won't jag my damn knuckles on it now.

It's mostly done for strictly racing engines (like NA 2l 10,000+ rpm 350hp) sort of stuff. And for high performance forced induction engines. Common practice for supercharged methanol 2000hp+ 70psi+ V8 drag engines etc.

[gldgti]

Yeah, i'm not really a big fan of the 'purchased horsepower' thing. I mean, there is a market for it and i don't bag the people that take that route, but i'd rather do it myself and do it my own way. Much more satisfaction and much less cost.

I think being able to use the odd bolt on part is good, but not just buying everything and having it fitted by someone else so you can say you engine has all this brand name gear in it and quote horspower figures you should be getting, but not really knowing why or how those parts work.

we need more people like you on this forum mate

[Preen59]

Here's a pic of the car trailer. We've mostly got it done. Just small things now like the tow hitch, guards and wiring (and of course, paint). We're going to use a cam system to tilt the trailer (similar to a hay bail turnover) so it won't need ramps. I'll explain when we make them.

[Preen59]

I wet blasted my block today. Didn't come up too bad. I didn't do a spot on job of it, i just blasted the majority of rust and paint off to clean it up. I also blasted out the water jackets to give them a good clean too.

Of course, 10 minutes after it had already started to rust again . But that's ok, i got it back to the workshop and coated it in CRC. So its now ready to go to the engine machine shop. Woo.

[Preen59]

we need more people like you on this forum mate

Don't say things you might regret!

[GoLfMan]

this 16v is going to be a crazy engine i got dibs going for a ride at nats first