high compression LZ22

[Rollover_Red]

Ok I needsa straight list of what parts/specs/details of what is involved in a high compression LZ22. I have a w53 head im going to build(cam, valves, porting) and I need to know what is involved with beefing up the bottom end.

[ggzilla]

No need to beef up the bottom end for 10:1 compression.

 

Or did you mean 15:1 compression like some racers use? That might need forged pistons.

[flatcat19]

Bore to 89mm with KA-E pistons on a peanut head will put it over the 10.0:1 mark. LZ23 goodness.

 

Quite a few different combos you can use. 

Lots of threads around here to read. 

[EricJB]

I built the motor Flatcat is talking about. You will find it scattered throughout this. 

 

http://community.ratsun.net/topic/39329-project-drag-521/

 

[datzenmike]

Ok I needsa straight list of what parts/specs/details of what is involved in a high compression LZ22. I have a w53 head im going to build(cam, valves, porting) and I need to know what is involved with beefing up the bottom end.

 

10.39 with closed chamber W53 head

9.787 with open chamber head.

 

The intake ports are a bit small for using on the larger 2.3 displacement. The difference between a 9.7 and 10.39 compression is only a few hp so get a larger port U67 open chamber. Get a dremel and port match the gasket to the head and intake. You can also do the cast exhaust. Polish the burrs from the ports too and if staying with the W58, you have lots of compression to spare so unshroud the valves.

[MicroMachinery]

If you use Z24 truck pistons, you can sit comfortably down around 8.5:1(and that's including the more efficient closed-chamber head).. that's what I opted to do my 2nd time around. 9.5+ is such a pain in the balls; you have to retard the timing a ridiculous amount, and paying for premium gets old really fast. The menial increase in power isn't worth what it costs you in the long run. Trust me.

[datzenmike]

Like a lot of 'racing' innovations it's the difference between winning and loosing. No expense is spared to gain every advantage in power, but for the street it like running a spoiler that doesn't do anything untill you're over 120. Compression increase (including higher octane gas) makes the engine more efficient by shortening the burn time and the loss of heat to the cooling system. More is available to do work. Going one point, say from 8.5 to 9.5 will add between 4-6%. From 9.5 to 10.5 maybe as much as 5%. 10.5-11.5 maybe 4% because you are getting closer to the idea,l there is less to gain. For 5hp it isn't woth the bother. 

[Rollover_Red]

Like a lot of 'racing' innovations it's the difference between winning and loosing. No expense is spared to gain every advantage in power, but for the street it like running a spoiler that doesn't do anything untill you're over 120. Compression increase (including higher octane gas) makes the engine more efficient by shortening the burn time and the loss of heat to the cooling system. More is available to do work. Going one point, say from 8.5 to 9.5 will add between 4-6%. From 9.5 to 10.5 maybe as much as 5%. 10.5-11.5 maybe 4% because you are getting closer to the idea,l there is less to gain. For 5hp it isn't woth the bother. 

the only reason why im looking into going higher compression, is because if im going to do all of this work to get the peak performance of this head with the cam, i need the compression ration to go with it. i fel like a stock z22e bottom end will not suffice the amount of fuel and air that is going into the bottom end. my 510 is in no rush to get done, and is not my only car. i dont care how long it takes or how much of a pain in the ass it is, no badass build gets done by sitting around. my 510 will not be a daily driver and i could care less about the fuel economy and what might give only 5hp, because for the head to work, i need the bottom end to work.

[ggzilla]

That is a myth. A high revving cam will still make more power even if you don't up the compression. Of course it will make more power if you increase the compression. Either way.

 

 

for the head to work, i need the bottom end to work

The bottom end needs to stay together, that's all. Ideal rod-stroke ratio is good for 1% per dyno tests, a real but very small difference.

[Rollover_Red]

Ok Thanks you guys. I guess ill just do a stock rebuild with stronger hardware.