Tall deck blocks and connecting rods?

[djwimbo]

I know it's been mentioned in previous threads on displacement increasing, but I'd like to know more.

I know the 2.0 8V blocks and the 1.9L TDI blocks will bolt to our trans. and that all the 4cyl have the same bolt pattern for the F/W's. So, is there an advantage to using the 2.0 or the 1.9? Better metal in one than the other? Easier to run catch can lines, lower cost... ??? Obviously the TDI will not need the grinding to clearance the TDI crank, but I'm not sure I'd want to use that one.

I'm not building an engine real soon, but when I do I'd like to be able to spin 7500rpm+ w/o any issues.

I know there's a mechanical advantage to using a longer connecting rod, has it been done in the 1.8T world? I'm interested more in the longer rods than displacement increasing.

- thanks

[mike-2ptzero]

Longer rods? I sure hope you mean using a longer stroke by using a different crank.


The stock 1.8t motors will rev to 8k without a problem

[killa]

I know it's been mentioned in previous threads on displacement increasing, but I'd like to know more.

I know the 2.0 8V blocks and the 1.9L TDI blocks will bolt to our trans. and that all the 4cyl have the same bolt pattern for the F/W's. So, is there an advantage to using the 2.0 or the 1.9? Better metal in one than the other? Easier to run catch can lines, lower cost... ??? Obviously the TDI will not need the grinding to clearance the TDI crank, but I'm not sure I'd want to use that one.

I'm not building an engine real soon, but when I do I'd like to be able to spin 7500rpm+ w/o any issues.

I know there's a mechanical advantage to using a longer connecting rod, has it been done in the 1.8T world? I'm interested more in the longer rods than displacement increasing.

- thanks

increased displacement for faster turbo spool, more torque
ABA block doesn't need any shaving to clear a 92.8mm crank
16mm taller which allows you to run 159mm rods, end up with 1.71 rod ratio and can run the 21mm wrist pins right off the bat.

Just a few advantages.

[djwimbo]

increased displacement for faster turbo spool, more torque
ABA block doesn't need any shaving to clear a 92.8mm crank
16mm taller which allows you to run 159mm rods, end up with 1.71 rod ratio and can run the 21mm wrist pins right off the bat.

Just a few advantages.

I'd like to increase the displacement, but it's not my #1 goal.

Who makes 159mm rods for VAG cars? from a TDI? 21mm wrist pins? I think I need to do some more research...

No mike, I mean longer rods. It may mean I have to make a phone call to get some custom pistons made, but I'd be willing to do that IF I do the build I want.
The American V8 guys have been increasing rod length for years. I've done a decent amount of reading on the rod length stuff. Although it's all tailored to the domestic crowd.

Stock rods are ~5.67"
the 159's I just learned are avail are ~6.26"
Very similar to what the V8 guys upgrade to. They start w/ a 5.7" and go up to a 6.125".

The greater the rod ratio the better, basically. I'm unsure at what point it would be too high.
144mm on 86.4mm: 1.66
144mm on 92.8mm: 1.55
159mm on 86.4mm: 1.84
159mm on 92.8mm: 1.71
TDI stock, 172mm on 95.5: 1.80
144mm on 95.5mm: 1.51
159mm on 95.5mm: 1.66

EDIT: 172mm rods have the same 48mm journal as other 4cyl, but have the 26mm wrist pins. 159mm rods have 21mm wrist pins and 48mm journals.

[djwimbo]

I found the answers I was looking for, at least for part of it...
Block info

The diesel's run a pretty small bore and a huge stroke. How far can they be bored out?
How about the ABA? stock it's 82.5, can an 84 or 85 fit in there?

[mike-2ptzero]

I'd like to increase the displacement, but it's not my #1 goal.

Who makes 159mm rods for VAG cars? from a TDI? 21mm wrist pins? I think I need to do some more research...

No mike, I mean longer rods. It may mean I have to make a phone call to get some custom pistons made, but I'd be willing to do that IF I do the build I want.
The American V8 guys have been increasing rod length for years. I've done a decent amount of reading on the rod length stuff. Although it's all tailored to the domestic crowd.

Stock rods are ~5.67"
the 159's I just learned are avail are ~6.26"
Very similar to what the V8 guys upgrade to. They start w/ a 5.7" and go up to a 6.125".

The greater the rod ratio the better, basically. I'm unsure at what point it would be too high.
144mm on 86.4mm: 1.66
144mm on 92.8mm: 1.55
159mm on 86.4mm: 1.84
159mm on 92.8mm: 1.71
TDI stock, 172mm on 95.5: 1.80
144mm on 95.5mm: 1.51
159mm on 95.5mm: 1.66

EDIT: 172mm rods have the same 48mm journal as other 4cyl, but have the 21mm wrist pins.

I was just saying that it isn't like we can just throw in longer rods into a block that uses a set rod length without having to make changes to the pistons so that the over all length is still the same.

[djwimbo]

I was just saying that it isn't like we can just throw in longer rods into a block that uses a set rod length without having to make changes to the pistons so that the over all length is still the same.

That's the fun part of custom right?

If you used 144 rods in the ABA and a standard piston, similar to the stock 1.8T your combustion chamber would be huge. There's 16mm more cylinder. That's over 5in^3.

I'm gettin all nerdy today, sorry.

[Wizard-of-OD]

That's the fun part of custom right?

If you used 144 rods in the ABA and a standard piston, similar to the stock 1.8T your combustion chamber would be huge. There's 16mm more cylinder. That's over 5in^3.

I'm gettin all nerdy today, sorry.

eh?

[djwimbo]

The ABA has 159mm rods vs the 1.8T's 144's. If you used the 144's in the ABA block you'd have a huge combustion chamber.

That's a 15mm X 3.14(41.25mm^2) Basically if the other factors remained the same: dish/dome, gasket thickness, head volume, etc. your combustion chamber would increase by 85.5cc.

It doesn't look like it would matter a whole lot either way at this point.
It looks like I'm interested in building an ABA short block and a 20V head, instead of my stock block. The 20/20 idea.

[djwimbo]

Good news, I might be getting a running ABA from work for the price of scrap. The only thing known to be wrong w/ it is that it ticks.

Was running and still strong(as a 2.0 can be) but ticked before removal.

[AudiA4_20T]

eh?

eh eh?

[djwimbo]

The idea that I'm fixated on right now is puttin an lightly built AEB head on a built ABA short block.

Question is, will it work in a longitudinal vehicle? I do not know. Anybody?

[pac1085]

theres a bunch of stuff that has to be done and its been covered a million times here and on AW. i decided it wasnt worth it and stuck with the aeb block / aba crank.

[djwimbo]

I found some interesting pics on the local forum on how to mate an AEB head and an ABA block "correctly". Guy is building a 2.1L 20V Turbo engine. Transverse car though.

Pictures thanks to Geoff. I'm pretty sure he's not on here....

ABA head gasket, AEB head.


Press fit and redrilled oil drain.


Head being prepped for the press fit oil plugs.

[Wizard-of-OD]

This thread is all over the place...

Enjoy:

http://forums.vwvortex.com/zerothread?id=1674618&page=1

[djwimbo]

I didn't want to look like a fool and say something like "Hey, check out this thread.." when you did the write up.

Which BTW is a great write up.

[chris164935]

If I went with an ABA block with 159mm rods (Do they make 159mm rods with 20mm wrist pins?) and an AEB crank, could I use pistons 1.8t pistons that are 83mm bore (with 9.5:1 CR), or would I still need custom pistons?
Also, am I looking at having to eliminate the intermediate shaft and oil pump in an ABA block to turn 10k+ RPMs?

[Wizard-of-OD]

If I went with an ABA block with 159mm rods (Do they make 159mm rods with 20mm wrist pins?) and an AEB crank, could I use pistons 1.8t pistons that are 83mm bore (with 9.5:1 CR), or would I still need custom pistons?
Also, am I looking at having to eliminate the intermediate shaft and oil pump in an ABA block to turn 10k+ RPMs?

External oil pump Chris?
Your always going to need custom pistons regardless what set up you do.

[chris164935]

External oil pump Chris?
Your always going to need custom pistons regardless what set up you do.

Well, I really like the 1.84:1 rod/stroke ratio; would be perfect match for my head. External oil pump not so much.

I have my 1.8t JE pistons that are 83mm bore with 20mm wrist pins. They won't work with 159mm rods (assuming I can get 20mm wirst pin rods) and the 86.4mm crank in an ABA block? Would be nice if I could still use them.

[Wizard-of-OD]

Cant :(
if you eliminate the IM shaft how you plan to turn the oil pump?

[djwimbo]

could I use pistons 1.8t pistons that are 83mm bore (with 9.5:1 CR), or would I still need custom pistons?

"custom pistons"? not really. They make "turbo" pistons for the ABA engines (21mm wrist pin). The only part that's custom is the valve relief for the 5th valve. The 1.8T 83mm bore piston may be too tall, but I know the wrist pin Dia. would be too small. 20mm vs 21mm. The crank end of the rods are the same Dia. but I unsure of any differences as far as clearance to the block.

The piston specs would have to be figured before purchasing. They may very well work. But I am unsure.

[djwimbo]

Well, I really like the 1.84:1 rod/stroke ratio; would be perfect match for my head. External oil pump not so much.

I have my 1.8t JE pistons that are 83mm bore with 20mm wrist pins. They won't work with 159mm rods (assuming I can get 20mm wirst pin rods) and the 86.4mm crank in an ABA block? Would be nice if I could still use them.

I'm sure there's a way. I'm not 100% on what measurements would have to take place. The AEB should be a 220mm deck height vs. 236mm of the ABA. I would think it wouldn't be an issue, except it's possible that it could change the compression ratio.

If you want to fit 20mm wrist pins into 159mm rods, I'd think that part would have to be custom. I doubt anybody wants to try and sleeve it and trust it to 8K+rpms.

[chris164935]

Cant :(
if you eliminate the IM shaft how you plan to turn the oil pump?

Well, would the stock intermediate shaft and oil pump setup in an ABA block be able to stack up to turning 10k+ RPMs? Perhaps shave the shaft to be smaller in diameter?

[Wizard-of-OD]

Well, would the stock intermediate shaft and oil pump setup in an ABA block be able to stack up to turning 10k+ RPMs? Perhaps shave the shaft to be smaller in diameter?

You can shave and balance the shaft ,thats what I did in my motors.The ABA block can go to 10K no issues.

[chris164935]

You can shave and balance the shaft ,thats what I did in my motors.The ABA block can go to 10K no issues.

It's the oil pump and its ability to maintain pressure at that hight of an RPM that I'm worried about. Can they handle it?

[Wizard-of-OD]

It's the oil pump and its ability to maintain pressure at that hight of an RPM that I'm worried about. Can they handle it?

Maintain pressure?
VW's run the highest oil pressure I have ever seen for a stock vehicle.you will be fine...trust me

[killa]

I'd like to increase the displacement, but it's not my #1 goal.

Who makes 159mm rods for VAG cars? from a TDI? 21mm wrist pins? I think I need to do some more research...

No mike, I mean longer rods. It may mean I have to make a phone call to get some custom pistons made, but I'd be willing to do that IF I do the build I want.
The American V8 guys have been increasing rod length for years. I've done a decent amount of reading on the rod length stuff. Although it's all tailored to the domestic crowd.

Stock rods are ~5.67"
the 159's I just learned are avail are ~6.26"
Very similar to what the V8 guys upgrade to. They start w/ a 5.7" and go up to a 6.125".

The greater the rod ratio the better, basically. I'm unsure at what point it would be too high.
144mm on 86.4mm: 1.66
144mm on 92.8mm: 1.55
159mm on 86.4mm: 1.84
159mm on 92.8mm: 1.71
TDI stock, 172mm on 95.5: 1.80
144mm on 95.5mm: 1.51
159mm on 95.5mm: 1.66

EDIT: 172mm rods have the same 48mm journal as other 4cyl, but have the 26mm wrist pins. 159mm rods have 21mm wrist pins and 48mm journals.

Yup, i've written a couple of those rod ratio combinations years ago,as well as displacement, some peeps shared it too.

As said before, ABA's have 159mm rods with 21mm pins. There is such a thing as the "law of diminishing returns" when it comes to rod ratios as well, meaning, don't always shoot for the 2:1.


Hope this helps

[mike-2ptzero]

Chris why in the world would you build a 9.5:1 engine that you plan on running a 42r and spin it at 10k rpm. The 42r isn't even going to get to its sweet spot till pushed at 40psi and then the 9.5:1 CR is going to be way too high.

[killa]

Well, would the stock intermediate shaft and oil pump setup in an ABA block be able to stack up to turning 10k+ RPMs? Perhaps shave the shaft to be smaller in diameter?

You should crack the block at the Intermediate shaft with 35+ psi and 10k rpm. The tensile load on shaft will be too much for that thin part of the block to take.

Getting rid of or balacing the Int. Shaft heavily and shot peening the block *might* help you keep it together. I had the porsche peeps that built my block do this as well.

[317ssayzarc]

You should crack the block at the Intermediate shaft with 35+ psi and 10k rpm. The tensile load on shaft will be too much for that thin part of the block to take.

Getting rid of or balacing the Int. Shaft heavily and shot peening the block *might* help you keep it together. I had the porsche peeps that built my block do this as well.

yea i removed half the weight when i had the thing turned down on the crank grinder

[chris164935]

Chris why in the world would you build a 9.5:1 engine that you plan on running a 42r and spin it at 10k rpm. The 42r isn't even going to get to its sweet spot till pushed at 40psi and then the 9.5:1 CR is going to be way too high.

Are 1.8t pistons taller than ABA pistons? Wouldn't the smaller stroke of an AEB crank put the dome lower into the cylinder of the ABA block, thus, lowering the CR?

[djwimbo]

yea i removed half the weight when i had the thing turned down on the crank grinder

Really? I'm interested in this as well.

[Wizard-of-OD]

Opposite
A 1.8T piston in an ABA block with an ABA crank + 159mm/20mm rods (assuming rebused from 21mm) will sit 2.2mm above deck.

[Militant-Grunt]

You may be interested in one of these pre-built 2.2 europec motors.

http://www.eurospecsport.com/2220V.htm

[Wizard-of-OD]

Or buy 1 from me....

[chris164935]

Opposite
A 1.8T piston in an ABA block with an ABA crank + 159mm/20mm rods (assuming rebused from 21mm) will sit 2.2mm above deck.

I know that.
What I want to know is with the AEB crank + 159mm rods, will 1.8t pistons still sit above the deck of an ABA block?

Also, would it be more practical to go from 21mm to 20mm wrist pins on the rods or bore out the wrist pin holes on the pistons to 21mm?

[djwimbo]

Opposite
A 1.8T piston in an ABA block with an ABA crank + 159mm/20mm rods (assuming rebused from 21mm) will sit 2.2mm above deck.

That's good info right there.

Or buy 1 from me....

That pic looks really familiar....

More info on that engine? Price, internals, power handling..? 034 is the first dealer they have listed on their site.

[djwimbo]

21mm to 20mm wrist pins on the rods

that part.

[chris164935]

What I want to know is with the AEB crank + 159mm rods, will 1.8t pistons still sit above the deck of an ABA block?

Any ideas?

[djwimbo]

being that there's 6.4mm difference between the two cranks, it would make me believe that it would sit 3.2mm lower than the 92.8mm crank, 159 rod/20mm pin and AEB style piston. I believe that would put it approx 1.0mm(.039") below the deck of the block.

I'm tired, don't believe me 100%