Mk1 16v Project

[GoLfMan]

Its JUST a mk1 4 door you know? I like it and i'm happy with what i'm doing, but its nothing that flash. Except the donk, it'll be pretty serious. Once i'm finished i'm going to build a full on race 1.8 16v. Solid lifter head light weight everything 9500rpm type stuff.

Edit: Having said all that, i'm glad theres other people that like it too. Thanks for the complements.

deerrrrr its just a mk1 4 door, i just love the serious engine prep thats going into this 16v, its old school cool with some nice engine building and engineering going into it, not just bolt on sh$t
to hell if its a 4 door, extra practicality

[Jarred]

I too like what you're doing with your mk1. taking the time to do it proper and making it look pretty sweet along the way. lookg forward to more updates for sure!

oh, and well done with the future job prospects!

[twin eng, twin turbs]

I'm taking the Karmann Ghia to the nats this year, but i'll take you up on the drive. .

Thats awesome your taking the karmann ghia it should be shown off more often as it is probably one of the cleanest ive seen! But it stiill dosn't have water cooling.... As yau know we have the same supertech oversize valves but did you realise that they are boardering on to big on the exhaust side and almost require new oversize seats aswell! See how yours go when they are cut and you'll no what i mean.

[Preen59]

I'm taking the Karmann Ghia to the nats this year, but i'll take you up on the drive. .

Thats awesome your taking the karmann ghia it should be shown off more often as it is probably one of the cleanest ive seen! But it stiill dosn't have water cooling.... As yau know we have the same supertech oversize valves but did you realise that they are boardering on to big on the exhaust side and almost require new oversize seats aswell! See how yours go when they are cut and you'll no what i mean.

Hmm interesting. I think bonk is getting G and G to do my head so i'll just have to see how it goes. The head is a 9a head and was very low K's when i got it, not that it makes much difference. Bonk said that .5 out of the throat of the insert should be fine, i hadn't taken a look though, because the head had no cams in it so all the valves were shut.

[Preen59]

More progress today.. Slightly.

MIC'd up the big end and main bearings.

The rods varied .02mm between them, but the mains were all within .005mm, which is 3/8ths of a mickey hair of stuff all. So i'll get the mains on the crank ground all to a set size and i'll only worry about individually sizing the big end journals.

Here's a pic when i was doing it, obviously i've left the bearings in the rods and the mains i have kept them in sets and numbered for the corresponding cap.



Oh, and i worked out why the 16v's and later have 3 piece centre bearings too. Making the centre thrust bearing in 3 pieces enables them to use a normal bearing for the journal and 4 thrust bearings that are all identical.

What this does is allow them to only have to tool for the 2 bearings, which is far cheaper and less complicated with no need for changeover etc, but also it means that on the production line they only need to have the 2 types of bearing available, this reduces logistical and mismatched part issues, which lowers the chance of running out of the parts on the production line.

You may not think that's interesting but i do.

[GoLfMan]

i think its very interesting and its a smart move to by VW production...

engineering like that i love except for when it is used to cat corners in quality and durability which it too often is!

[Preen59]

i think its very interesting and its a smart move to by VW production...

engineering like that i love except for when it is used to cat corners in quality and durability which it too often is!

Tell me about it. I work for a white goods manufacturer. "We can save $450 000 a year if we go from .55mm steel to .45" And i say "yes, but if we do that, scrap will go up, the machines will be more temperamental" etc etc, and they say "well there's a cost reduction here, you guys will have to make it work". Engineering being controlled by accountants.. Gotta love it.

I'm glad to be back in the toolroom away from that crap again.

[Oneofthegreats]

Good to see more progress & top notch work on this.

What are you setting up your clearances to?

Don't know what the VW spec is, but I try & set my V8 stuff up with 0.0025" big end's & main's.
End float - 0.006"

Also with ring's I go.

Top Ring .0045" for every inch of Bore eg. 80mm = 3.149"
2nd ring .0050" for every inch of Bore
Oil Ring rail gap .015" for every inch of Bore

This may be the same for VW as a small engine is still an engine & still has to have tolerances

[Preen59]

Good to see more progress & top notch work on this.

What are you setting up your clearances to?

Don't know what the VW spec is, but I try & set my V8 stuff up with 0.0025" big end's & main's.
End float - 0.006"

Also with ring's I go.

Top Ring .0045" for every inch of Bore eg. 80mm = 3.149"
2nd ring .0050" for every inch of Bore
Oil Ring rail gap .015" for every inch of Bore

This may be the same for VW as a small engine is still an engine & still has to have tolerances

Good question..

I asked Collin at TT and he just quoted me out of the bentley book (he was looking it up while i was on the phone to him) so i'm probably going to go for standard clearance upper tolerance (higher clearance). I can't remember what they were but i do remember that the big ends were different to the mains. I will discuss it with Silky though, as i'm getting him to get the crank done anyway.

The ring gap you're talking sounds pretty run of the mill, but once again i'm not sure what gap i'll run at the moment. as you know you basically want as little as possible without it touching when it warms up.

**For anyone who doesn't know what we're talking about here, the ring gap is the gap between the 2 ends of the ring when it is in the bore, you simply measure it with feeler gauges.

You need a gap between the 2 ends of the ring when it is cold, because as the engine heats up (and the rings), the ring will grow, or get longer due to thermal expansion.

If the ring gap is inadequite, when the engine heats up and the ring grows, the ends will push together and the ring will distort and this does a few things:

-The ring deforms and nolonger seals on the bore, causing blow-by, blowby will overheat the ring and it will lose its tension.
-Also, when the ends touch, they push outward and score the bore.

So, when you go to put a new set of rings in because they've lost tension and you're getting too much crank case pressure and HP loss, when you hone the bore, the ring score will still be in the bore, and you will have to hone 2 or so thou or more out to clean it up.

Then you have too much bore clearance and you see where i'm going with this i'm tired, time for bed.

Any questions, just ask.

[Jarred]

Yeah I get that. In theory only though. So expect alot of questions if I ever decide to rebuild an engine!

What happens, though, when the bores have too much clearance - do you need bigger rings to suit??