Guest Stoker3.0Z Posted May 13, 2005 Share Posted May 13, 2005 I have been reading alot about the differant rod/piston/gasket/head combos you can use to gain compression for the strokers. With the 280Z rods and 280ZX Flat tops you can get 10.6:1 compression with a 2mm gasket and 1mm mill on the pistons. But is this safe to use on the street as a reliable caburated car on pump gas? Or should I go with 240z rods with the 720 pistons and keep it around 9.5:1? My mechanic told me that the differance between 9.5:1 and 10.5:1 is only 4% HP gain, I'm not sure that is worth it to have a possibly unreliable car for only 8-12 HP.....whats your opinion? Mike Quote Link to comment Share on other sites More sharing options...
COZY Z COLE Posted May 13, 2005 Share Posted May 13, 2005 Check this link...... http://zhome.com/rnt/L28conversion/3031FAQ.html LARRY Quote Link to comment Share on other sites More sharing options...
Guest Stoker3.0Z Posted May 13, 2005 Share Posted May 13, 2005 Check this link...... http://zhome.com/rnt/L28conversion/3031FAQ.html LARRY I read all that, thats where I got my info from..but I was wondering what a good streetable ratio is...all that says is how much compression you get from what set-ups. I was wondering what a good compression ratio I could have to use pump gas and have a reliable car. Quote Link to comment Share on other sites More sharing options...
olie05 Posted May 13, 2005 Share Posted May 13, 2005 well, you can easily run 10.5:1 on the street, of course you would want to run pump gas, but what your mechanic was telling you about only a 4% increase is false. The good thing about raising the cr is that you can get the most out of a big cam. If you put a big cam on a low cr motor, it will lower the dynamic cr too much by bleeding off pressure in overlap and actualy hinder performance. The increase you will see by switching to a higher cr and larger cam will be alot more than 4%. If you just do one or the other you won't see such a noticeable increase. I am running 10.3:1 on my engine and just use premium, and with the stock cam, and 2580lb I ran 14.8s in the 1/4. Obviously the compression did something over the stock 16s 1/4 of the 280z. you won't start getting unreliable until higher than 10.5:1. that is the highest you can run on premium on these engines. That is the general sentiment on this board. -Oliver Quote Link to comment Share on other sites More sharing options...
Guest Stoker3.0Z Posted May 13, 2005 Share Posted May 13, 2005 you won't start getting unreliable until higher than 10.5:1. that is the highest you can run on premium on these engines. That is the general sentiment on this board.-Oliver With Diesel Crank from the maxima 280Z rods and 280ZX Flat top pistons the compression ratio is 10.6:1 with 2mm gasket and pistons milled 1mm. Is 10.6 pushing the limits of pump gas or is that close enough to 10.5:1 to be "safe"? I don't want to worry about ping every time I drive the car and would like it to be fairly reliable and not give me problems every other day. Quote Link to comment Share on other sites More sharing options...
olie05 Posted May 13, 2005 Share Posted May 13, 2005 good tuning will get you around the ping issue. Other things you can do to make it more reliable is to use a header (duh) to keep the gasses flowing and smooth the combustion chamber, like spark plug threads that aren't needed, stuff like that. Check out the detonation post in misc. tech I recently revived. It has alot of good info. Quote Link to comment Share on other sites More sharing options...
Guest iskone Posted May 13, 2005 Share Posted May 13, 2005 My setup nets 11.7-1 N42 Block 240 rods 5cc Domed pistons 1mm over .080 shaved Early E88 with 45cc chambers (I think) 278* .580/.580 108 cam 1mm MHG I run pump gas (92) without any problems. Chamber design and a big cam are the keys. Isk Quote Link to comment Share on other sites More sharing options...
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