1.6 Compression Specs and question

[silentdub]

I am about to tear down this 1.6 and send it off to the machine shop. I will have the head resurfaced as well as the block. I am wondering what the current spc is for this motor 20:1?

I am guess it is about 20:1, would anyone recommend bumping it up to say 20.5 or 21 for a little more power or is this not a good idea?

For those that changed it, how much did you shave off the head?

2nd question, Oil squirters, are they standard on the 1.6? Should I add/install them if not?

This is a non turbo and I am keeping it that way.

[bajacalal]

Factory specs on this thing are something around 22.5 to 1. That's a lot of pressure, even for a diesel. I don't see how much more you could get away with, these are EXTREME interference motors with little room to spare, the valves when closed sit like 0.30" from the piston top at TDC. You might need to use of a thicker head gasket if material is removed from the block or head.

Oil squirters were standard on turbo blocks and I think VW started adding them to more engines later on, it wouldn't be a bad idea to add them if yours doesn't have them but not necessary on the NA. You might want to consider a higher volume oil pump if you add them.

[R.O.R-2.0]

just leave it as it is.. VWs have some of the highest compression ive ever seen on a diesel..

oil squirters are not necessary,as was mentioned.. no n/a VW diesel 1.6 EVER got oil squirters that i know of.

only some of the industrial engines, and most of them were 1.7 and 1.9 blocks.

[silentdub]

Gotcha, so if there is no reason in increase compression, then so be it.

I would add the oil squirters, I hear that they really help keep the pistons cool, so I figure why not.

Thanks for the answers!

[bajacalal]

@ROR I was thinking of engines like the 2.0 gas.

@silendub It's not that there's no reason to do it, it's that it's not feasible. The engine design just prevents it without, I would imagine, having custom pistons or something made, which doesn't make economic sense. The way to make more power with these engines is a turbocharger.
Remember, things that affect performance in gasoline engines don't necessarily apply to a diesel.

[silentdub]

@ROR I was thinking of engines like the 2.0 gas.

@silendub It's not that there's no reason to do it, it's that it's not feasible. The engine design just prevents it without, I would imagine, having custom pistons or something made, which doesn't make economic sense. The way to make more power with these engines is a turbocharger.
Remember, things that affect performance in gasoline engines don't necessarily apply to a diesel.

understood. This is my first diesel engine rebuild, hence the reason I am asking questions. I am building a sipster so power isn't my goal, just MPG.

Is there are reason to use a thicker gasket and lower compression a little?

[R.O.R-2.0]

if you want to make your engine a sipster, a thicker gasket is going to be counter-productive..

run the right gasket for your piston protrusion.. thats the only way its going to get you maximum MPGs..

you are not running loads of boost, or anything like that, and the compression is already stupidly high on these engines, so basically, you have no reason to need to have the compression at any other number than where it is at factory..

the squish and quench is important on these engines.. and the head gasket thickness determines that..

[maxfax]

I think it was bought up before that slightly lower compression could improve economy.. I remeber reading somewhere that the biggest reason for the stupid high compression was for easier starting when selling these things to the masses..  Wonder what an AAZ head would do for this combo..

[silentdub]

I think it was bought up before that slightly lower compression could improve economy.. I remeber reading somewhere that the biggest reason for the stupid high compression was for easier starting when selling these things to the masses..  Wonder what an AAZ head would do for this combo..

That can make sense, but ya know, the regular gasket will be fine then. I am not that familiar with the N/A Diesels so I figured I'd ask.

How about different cam profiles? Stay stock for MPG or is there a better choice?

[R.O.R-2.0]

I think it was bought up before that slightly lower compression could improve economy.. I remeber reading somewhere that the biggest reason for the stupid high compression was for easier starting when selling these things to the masses..  Wonder what an AAZ head would do for this combo..

That can make sense, but ya know, the regular gasket will be fine then. I am not that familiar with the N/A Diesels so I figured I'd ask.

How about different cam profiles? Stay stock for MPG or is there a better choice?

heres what you should do if you want more mileage:

free flowing intake and exhaust systems.
good transmission
turn injection pump down
properly inflated tires
no more weight in the car then is absolutely necessary..

opening up the intake and exhaust will really make a big difference in power and economy.

if your car ever smokes black, you are getting bad mileage..

[R.O.R-2.0]

I think it was bought up before that slightly lower compression could improve economy.. I remeber reading somewhere that the biggest reason for the stupid high compression was for easier starting when selling these things to the masses..  Wonder what an AAZ head would do for this combo..

VWs do start very easily compared to other similar IDI diesels. my datsun pickup needs the glow plugs to start it even if you just shut it off hot 10 mins ago..

and what about a AAZ head? on an n/a? that might be kinda cool?

[silentdub]

I think it was bought up before that slightly lower compression could improve economy.. I remeber reading somewhere that the biggest reason for the stupid high compression was for easier starting when selling these things to the masses..  Wonder what an AAZ head would do for this combo..

VWs do start very easily compared to other similar IDI diesels. my datsun pickup needs the glow plugs to start it even if you just shut it off hot 10 mins ago..

and what about a AAZ head? on an n/a? that might be kinda cool?

AAZ head? Don't currently have one nor the money to invest in it.

[rabbitman]

The compression ratio for the 1.6D is 23:1 and the 1.5D is 23.5:1.

There's other option for cams and that's through Giles, they're call high performance but they'll probably get you better mileage too.

[trav1856]

I was old anything over 6lbs boost on an NA engine will melt the rings. Anyone confirm?

[R.O.R-2.0]

I was old anything over 6lbs boost on an NA engine will melt the rings. Anyone confirm?

no, i cant confirm it, but i can tell you its un-true as hell.. i run around 20 psi to my n/a all the time.