What cam is this? Suggestions for replacement?

[Oneofthegreats]

When it comes to building engine's, I like to keep detailed record's of what get's done & what goes into them.

The engine was rebuilt in 98, so it was a far while ago now. Has clocked up over 370+k with only a headgasket failure.

I wouldn't suggest skimming the head super thin to raise the CR, as this can cause mixture & ignition problem's.

I ended up fitting new piston's which had a smaller volume & higher deck height.

I should have posted this up before to save confusion
Here's all the dismantled & assemble spec's


GX Engine

Bore - 81mm
Stroke - 86.4mm
Swept Volume Per Cylinder – 445.398cc
Engine Capacity - 1781.582cc

As Dismantled/As Assembled

DeckDeck height -

1.00mm/0.60mm

Head gasket height -

1.65mm/1.65mm

Piston Crown Volume -

17.69cc/11.27cc

Deck Height + Gasket Volume -

13.6609cc/11.5989cc

Cyl. Head Volume -

30.00cc/ 30.00cc

Compression Ratio

Piston Crown Volume -

17.69cc/11.27cc

Deck Height + Gasket Volume -

+13.6609cc/+11.5989cc

Cyl. Head Volume -

+30.00cc/+30.00cc

Total Combustion Chamber Volume

=61.3509/=52.8689

Swept Volume -

445.398/445.398

=506.7489/=498.2669

Total Combustion Chamber Volume -

+61.3509/+52.8689

Compression Ratio

= 8.2598:1/9.4246:1

Cam Specs – Stock GX

In Opens 15°BTDC
In Closes 55°ABDC
Ex Opens 55°BBDC
Ex Closes 15°ATDC

Duration In + Ex 250°
Lift @ Lobe .360”

As you can see, a Autotech 270 is a much bigger cam.

If you just going to fit a Hydraulic G Grind, I wouldn't bother about HD valve spring's, just lifter's. But on the other hand, if the engine has had a hard time for most of it's life, new spring's wouldn't be such a bad idea.

Just out of interest sake, the Autotech 270 is $129.95US. They should post to OZ.

[Peter Jones]

Ok, that makes sense, thanks for taking the time to write it all up.

For now I don't really want to tear the whole motor down, so I don't think I'll be replacing pistons until I tackle the project motor.

If I do the pistons and rings I'd have to bore it and while I'm there I'd have to do the big ends, and if I did those I'd have to do the mains etc etc.

First rule of any project. Define scope.

I'm in the defining scope phase at the moment and trying to get a feel for what can be done beyond just sticking the head back on.

Hard to say what sort of life this motor has had. The previous owners were a couple of kids that neglected it. I don't think they could have driven it to hard because the fuel pump was stuffed when I got it and the throttle cable was so badly adjusted that the secondary wasn't pulling in. I think the owner before them must have fitted the 5 speed and K-Jet motor.

All the kids did to it was cut AND oxy the front springs

I'll see what my head guy has to say. it might be possible to get that CR up by other means, he's pretty handy at designing and shaping combustion chambers. Just depends how generous he's feeling. I don't know if he's still got the pantograph, that thing always amused me. He had all the VW combustion chamber reference models to go with it once upon a time.

I'll go and check out autotech tonight, I've already spent too much time on the net at work today.

Pete

[Jarred]

Pete, If you are planning on doing a project engine, it might be wise not to use up all your favours with you head fella. He could come in very handy for some full on work on perhaps a 2L 16V, which I'm my opinion is probably worth it as a next step.

8V are good for street and general use, but you can get so much more power out of a 16V, it's almost not funny.

having said that, my scope on this project would (just briefly): get the head back on with a bit of work (stage 1 kinda stuff; "mild street" perhaps) and get some more laps under your belt. Learn how to drive/race first, then by the time you are really confident, and at the absolute limit with the 1.8 8V you'll be able to pop in a worked 16V and progress from there.

That's just what I'd do, just my 2 cents. It's not really worth sinking a whole lot of coin in an engine you are planning on replacing in the near future.

[Peter Jones]

There's plenty of favours left in that bucket, I needn't worry on that score.

I've spent many weekends down at the shop repairing or re-wiring his phones, internet, alarm, mills, lathes lights etc. I just finished the phone cabling in his new house after Christmas. Basically we never charge each other for labour, just out of pocket material expenses. I can go down there and use any of the machines myself if he's busy or I can do some of the grunt work for him while he works on my stuff. These days we don't get to catch up too often because I work in town now and it's hard to get to the shop when he's open. To get the head to him I'll have to pop around to his place one night this week because he's not opening up on Saturdays any more.

Agree with you on the conservative approach for the moment, there's bigger things to come.

Pete

[Peter Jones]

Good range of cams here.
http://www.bahnbrenner.com/vw_audi/c..._Hyd_Camshafts

Makes me want to build a crazy 8v.

Pete

[Oneofthegreats]

Just letting you know Pete.

From what I've read, BBM are more of just supplier/distributor. There own product's are sceptical & over priced IMHO!

Eg. The cam's spec's are the same as TT (Techtonics Tuning) cam's right down to the TT part #'s & are more than likely the same cam's.

http://techtonicstuning.com/camsspecs.asp

[Oneofthegreats]

8V are good for street and general use, but you can get so much more power out of a 16V, it's almost not funny.

Just out of interest sake.

It's actually been very well documented that it's easier to gain NA power out of a 8V on a cost vs power ratio due to the 16V poor cyl head design, which has been regarded as the worst designed VW cyl. head 2nd behind the VR6.

I've only read this & haven't done it, but they say it's also easier to extract double the output of an 8V vs 16V NA tuned.

In saying that though, if I had some spare coin for a nice daily driver, I personally wouldn't mind building a simple 2L 16V setup with Microtech LT8, EFI Hardware 45mm throttle bodies (The Badger5 complete 16V setup is £2350.00 GBP http://www.badger5.co.uk/ ), CR 10.9:1, cleaned up port's, TT 276° cams, 4-1 extractor's & 2.5" full flowing system.
Should make easily 200+hp properly tuned & be reasonable on the go juice.

But for less money, I could also throw a turbo on the 8V & make the same HP easier & with a ton more torque, which I reckon would be much more fun!

6 of one, half a dozen of the other. Your choice.

[Jarred]

Yea, I agree Tim.

Although I know nothing about the head designs, just from driving my 1.6 in the Golf, it was a much easier engine to drive, (and thrash) than my 1.6 16V (in the laser)

Sure the 8V was modified slightly, but the 16V you really have to ring it's neck to get power out of it, where as the natural tourqey-ness of the 8V makes it a much more streetable engine IMO.

Having said that. If I were to spend some dosh on a "race" engine, I would go a 2L 16V for sure. A nice set of cams, and well pretty much all the work the Preen is doing to his engine, I'd do if I was building a full blown Race engine. hence my recommendation to Pete.

Sure an 8V can get good power, more so with a turbo (duh) but a turbo on a 16V, would be exponentionally beneficial.

OF course it comes down to money. 8V has half the cams and valves, so it's already a bit cheaper. but money now object (or less of an object) a 16V for it's tunability.

Having said all that. I'm pretty sure I've just reapeated what you've said Tim, but just using different words! hahah oh well.

[Golf Loon]

Beau and I were talking about this last weekend. A crazy 8v is quicker and more reliable than all but the most extreme 16v.

Also consider the american aba crossflow heads they can make stupid power from an 8v and can run kjet

[GoLfMan]

i think i'd be more inclined to build myself a pretty crazy 2L 8v twins, big valve head, serious porting and all the exhaust hizzle dizzle for racing.

Torque wins races