Cross Performance 084 cylinder kit review

[Brewz]

Hi folks

My 084 kit turned up today

I am neither excited or disappointed. Just kinda......... Meh

Firstly I will say that the quality is very good. It woult work perfectly as a mildly ported bolt on option if your toasted your 084 and would work well.
Its fits and bolts on with no issues at all.

I have a nice OEM top end to compare it too so I will list some specs and pics below

Port timing (no gasket)

OEM: 97.5/120/70
CP: 96.5/124/5/74

Transfers were measured with a piston ring
The OEM uppers open at the intake side first by a smidge and are even both sides.
The CP uppers open at 124 on one side and 125 on the other side and open at the exhaust side a bit before the intake side which is not preferred, but not the end of the world.
CP lowers are more open towards the cylinder base but the uppers look smaller and les open towards the intake side compared to the OEM cylinder.

CP intake is lower and appears to be slightly wider and squared. More open on average.
CP Exhaust is higher which is heartbreaking (100 would have been nice) but is wider and nicely shaped.

CP cylinder looks to have its band chrome plated which will make things fun for porting.

CP piston looks really nice but has much smaller windows. I have not weighed them yet.

For my 084 build I want to port for performance so I will be using the OEM piston and cylinder as it has better numbers and I can grind it to the same of better than the CP cylinder.

If I had a toasted 084 needing a top end, I would have no hesitation in just bolting one of these on as I recon it will run great as is.

I will be keeping my cross performance kit as a spare or for when I get a 90* grinder so I can do justice to the uppers.
The OEM jug will be mildly ported and lowered to get the exhaust down around 99*

 

[Brewz]

OEM transfers



CP transfers

 

[Brewz]

OEM intake



CP intake

 

[Brewz]

OEM exhaust



CP exhaust

 

[Mastermind]

I ran a 084 over the weekend with a Cross Performance top end. It was a damn good runner.

 

[Brewz]

Pistons

OEM Left, CP Right

When I mount them on a wrist pin, height and skirt are spot on identical

OEM piston windows are much bigger but thats nothing a bit of grinding wont fix on the CP piston

 

[Brewz]

I ran a 084 over the weekend with a Cross Performance top end. It was a damn good runner.

Id believe it
They are a nice looking kit and I am very happy to own one.
I want the exhaust lower and the transfers higher so I will keep it till I have the gear to do it justice.

I was very happy with my CP 076 kit and as I said...... if I was just after a bolt on top end, I would have no hesitation in using it, and I will one day.

Just being critically picky for those of us that dont have all the gear to really port properly if thats what we want from it

 

[Mastermind]

If I had made the prototype, it would have been done with a lower exhaust.

 

[spencerpaving]

That cyl looks like it could run very well...why do you want ex lower?

 

[Brewz]

If I had made the prototype, it would have been done with a lower exhaust.

Well........... whats holding you back?

We need a MMWS on the side of it

 

[Brewz]

That cyl looks like it could run very well...why do you want ex lower?

Its a preference thing
Some like a higher exhaust and that's fine, but if your doing a performance casting, why not start with a lower exhaust so if you want it higher, you can grind it there.

For me, lower exhaust works better in the hard wood we have in Australia.
High RPM is not king here. Too much chain speed just makes even the sharpest of cutters skip over the rock hard timber in stead of digging in and actually cuts slower and will stretch the chain more that you would believe.
Lower exhaust gives a longer duration of push on the piston which equates to torque in my book.
We need to keep the chain moving at a speed where the chain is able to dig in effectively and this takes more power.

Add a 40 to 50" bar and lower PRM with increased torque actually becomes desirable.

I have never cut timber I could dint with a hammer!

 

[Brewz]

Well........... whats holding you back?

We need a MMWS on the side of it

Oh.... and then another sale so we poor bastards in Australia can afford one

 

[Ikeholt]

Anybody have an update on these kits?