11.1 Compression From My 5K

[mr04ag]

Hi kids,

 

I've got a 5K in my KE26 with a Tighe 104 (from memory) cam, headers, a fresh bottom end and a redline manifold with twin side draft Dellorto's on it...

It's just done a head gasket and while it's apart i'm wanting to match port the head to the inlet manifold, install an electronic dissy, and up the compression to 11.1, i've read stuff on the net about the 5K having dished pistons and not much head height or something, is it possible to deck the head enough to achieve this much compression? or will i crash things?

Ideally i'd like someone to say, take XXX thou from your head and you'll have 11.1 compression, but i'm sure it's not that easy?

Also, can i use a 4K electronic Dissy in my 5K? or are the gears or soemthing different?

 

Thanks in advance for any help! If this info is around somewhere already i'll happily read it there if someone can link me? i can't find it cos i'm pretty useless on computers...

 

Dave

[GJM85]

Hi father knowledge,

 

For starters that's quite an excessive CR so you'll need things like spec head gasket and piston rings, head studs. I could be wrong. Also note that the 104 cam by Tighe usually requires a regraphed distributor so if you want to change dizzy you may need to look at that.

 

There is a part you can get through 'Hot Spark' to convert a breaker dizzy to a electronic and with a already graphed dizzy would work out to be a far cheaper option.

 

Hot Spark

Edited May 9, 2011 by GJM85

[snot35]

You've just done a head gasket and you want to increase the chance of it happening again? :)

 

Why did it go?

 

Nice work on hot spark GJM, that's a good find.

[mr04ag]

Not sure why it went? Just did...

I'll check out that HotSpark thing.

I didn't think i'd need to change my rings??

It doesn't need to be 11.1, I just want to up my compression as much as possible while the head is off... if that's 10.5 or something then that'll do...

 

Does anyone know where i can get a flash head gasket and stud kit from? i'm having trouble finding much in the way of performance parts for a 5K...

[Figjam14]

i run more then that and runs fine

[GJM85]

Just get your get shaved down to its lowest. After a blown head gasket you'll want to anyway. There are indicators along the underside of the head. Just do it like normal and see how it goes. Many people claim it will go fine... and you can always get another head if it doesn't.

Without doing flat top pistons you'll probably not see 11:1 unless you boost it.

[snot35]

I'd really be finding out why it went before messing with the formula. Otherwise you'll be doing it again sooner rather than later.

[philbey]

Sorry mate but this discussion is pointless unless you know what your current compression ratio is. We cannot tell you squat, for all we know you might have a heavily shaved head or shallow dish pistons and already very high comp.

 

Read up this page and download the software, it's very handy, it will tell you static and dynamic comp. You will need a reasonable (although not expensive) set of calipers, you'll need to measure the bore, piston sizes and calculate the volume of both the head and the piston dish etc. The calculator will tell you what your compression is.

 

THEN, once you know your compression, you can start adjusting numbers to work out how much you need to shave your head to reach 11:1. Asking here for a simple "take 10 thou off" won't get you anywhere.