can anyone explain the various ways the engine capacity has been changed, iv heard talk of stroker kits, and getting rebores, 88mm pistons etc - what are the pros and cons, costs of each one, and what do they actually do???

 

cheers peeps

Well a stroker kit usually increases the capacity and the engine and sometimes even changes the throw of the crank, main pro is the increased capacity and thus power and torque and stroker kits are usually made of the best materials so very very strong for big power. The cons, well apart from price the only main con is you need a very good block to rebore to a decent level so when i did mine i had mine tested for any inperfections before i took mine to 3.2ltr.

 

I think JUN are about the only people whi make a full stroker kit for the zed and its not cheap prob looking at the best part once you ship it over of 8-10k for the full kit or just do what i did and change the pistons and rods and get the crank tested to make sure its within tolorance levels as the standard crank on the zed is very strong anyway.

 

HTH

 

Mike

cheers bud - so a stroker kit is essentially a rebore with extremely strong internals?

 

am i right in thinking youd need 92mm pistons to rebore to 3.2ltr, or would different conrods also affect the capacity (if they were shorter?)?

 

 

standard crank and rods are fine up to about 600bhp right?

 

 

sorry for all the questions - if i do get any work done will only likely be 87.5 or 88mm, just trying to get a better understanding of the internals!

cheers bud - so a stroker kit is essentially a rebore with extremely strong internals?

 

am i right in thinking youd need 92mm pistons to rebore to 3.2ltr, or would different conrods also affect the capacity (if they were shorter?)?

 

 

standard crank and rods are fine up to about 600bhp right?

 

 

sorry for all the questions - if i do get any work done will only likely be 87.5 or 88mm, just trying to get a better understanding of the internals!

 

If your not looking for big power then yes 87.5 or 88mm is more than enough, if i was chasing 600bhp then i would change the rods as you dont want one of them going!! 90mm take the zed engine to jut about 3.2 i think 92mm which is right on the limit for the block takes it upto about 3.4 ish if i'm not mistaken :)

 

Mike

This is a great article on the VG30DETT engine:

 

http://www.sportcompactcarweb.com/projectcars/9909scc_proj300zx/

 

Note the part about overboring this engine.

 

-Andrew

thanks guys, am now seriously considering 87.5 or 88mm, will keep getting more info before i decide. iv had a local engine builder recommended to me, what sort of quote should i expect from him for preparing the block for the new pistons?

thanks guys, am now seriously considering 87.5 or 88mm, will keep getting more info before i decide. iv had a local engine builder recommended to me, what sort of quote should i expect from him for preparing the block for the new pistons?

 

Ask Peter Nendels or Marcotwin they both are building JUN stroker engines :D

Now heres where it's different

1) I'd be doing it to an NA (zip it TT owners)

2) Targeting the 0.2L in stroke rather than bore as many have done previously.

This way you get far more torque. Keep the same compresssion ratio an you can get a stock NA producing close to 240hp approx 177hp at the wheels, not to mension the touque increase, this would have the most effect.

 

And I would guess this could be done a lot cheaper than JUN sell there kit for.

As the hp is not outrageous just work with the original crank and grind it?

 

Am I way off?

 

Max

 

(Down under)

Ask Peter Nendels or Marcotwin they both are building JUN stroker engines :D

 

 

1 is built and for sale. Nend posted it up for saleearly last week. Full jun internals.

Now heres where it's different

1) I'd be doing it to an NA (zip it TT owners)

2) Targeting the 0.2L in stroke rather than bore as many have done previously.

This way you get far more torque. Keep the same compresssion ratio an you can get a stock NA producing close to 240hp approx 177hp at the wheels, not to mension the touque increase, this would have the most effect.

 

And I would guess this could be done a lot cheaper than JUN sell there kit for.

As the hp is not outrageous just work with the original crank and grind it?

 

Am I way off?

 

Max

 

(Down under)

 

Thats a lot of money for a 15hp increase....torque would go up a bit...but still....money better spent elsewhere IMO

Now thats what I've been waiting for, to finally see the JUN 3.4 Stroker kit actually fitted into a Z :hyper:

And if money were no object is exactly where I'd put my money as Reading up on the Z block (Above link is indeed one of the best detailed research articles explaining a good build) It would seem that the walls of the Z block are not that thick to take too much on an oversized rebore.

But I'd say go for what you need, no point spending £8k on 3.4 Kit if you really aren't going to need that size displacement for the finished project.

More essential is getting the the job done properly and the build quality, better to go in once, than find that if you've only done the pistons for a little bit extra you may have well just replaced and also upgraded the conrods.

Make sure you have a good solid (no weakness or stress cracks appearing) block also, though a good engine builder will be able to check for you.

A good quality solid and forged engine build is the foundation for which you can then have more peace of mind when adding the power from any further upgrades...

All the best. ;)