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Re: d15z1 / d16y5 VTEC-E Squad!
Originally Posted by Bense
(Post 52483808)
I've got threads where I've written about almost exactly what you're describing. Its an interesting project. I wound up going another route.
I'm at a point in my life, career where I cannot allow myself to venture off into academic projects such as VTEC-E. I am able to continue to pursue my passion with building Honda transmissions because I'm doing stuff for J-series / FK8 Type R. There's pretty much zero possibility of being able to earn money working on Hondas by developing parts / pursuing engineering projects that would cater to the fuel efficiency crowd. You'd end up doing more work, making less money. |
Re: d15z1 / d16y5 VTEC-E Squad!
Originally Posted by MauricesExoticP
(Post 52487002)
Oh absolutely, of interest I believe is that the Z1 valvetrain appears lighter than the Z6/Y8 valvetrain. Come November I'll have rough cam information on the Z1 cam to verify lift and duration numbers. I'll do the work with a dial indicator and degree wheel, that will not be hyper accurate but it will work as a functional comparison to the Y8 cam I have.
At one point I had; D15Z1 - 1992-1995 Civic VX D16Y5 - 1996-2000 Civic HXD16B5 - 1998-2000 Civic GX - compressed natural gas version of D16Y5. The HX engine is much better than the VX engine. Any possible advantage in fuel efficiency that the VX head would have over the HX head is going to be so minimal that you'd have a difficult time proving it. -- On the contrary, the advantages that the HX head has over the VX head is going to be immediately apparent. I tried to order D17 Civic GX pistons in 2005-2006, but they weren't available. It's plausible that you'd have an easier time finding them out of a junkyard D17 GX engine. I was going to build a D15Z1 block with D17 pistons, with a D16Y5 head. While I waited and waited and waited for the backordered pistons, I found a D16B5 for cheap and I did a build with that. Good luck with your project. |
Re: d15z1 / d16y5 VTEC-E Squad!
Originally Posted by Bense
(Post 52487275)
The d15z1 has much smaller valves and likely weaker valve springs. I recall selling a d15z1 rocker assembly to eigerzoom / digital congo off of a d15z1 swap that I got for free and parted out. That would have been 2005-2006ish.
At one point I had; D15Z1 - 1992-1995 Civic VX D16Y5 - 1996-2000 Civic HXD16B5 - 1998-2000 Civic GX - compressed natural gas version of D16Y5. The HX engine is much better than the VX engine. Any possible advantage in fuel efficiency that the VX head would have over the HX head is going to be so minimal that you'd have a difficult time proving it. -- On the contrary, the advantages that the HX head has over the VX head is going to be immediately apparent. I tried to order D17 Civic GX pistons in 2005-2006, but they weren't available. It's plausible that you'd have an easier time finding them out of a junkyard D17 GX engine. I was going to build a D15Z1 block with D17 pistons, with a D16Y5 head. While I waited and waited and waited for the backordered pistons, I found a D16B5 for cheap and I did a build with that. Good luck with your project. The Z1 valvetrain fits in a Y8 casting (selected mainly because of the superior combustion chamber over the Z6 casting). My Y8 head is lightly ported on the intake side and only polished on the exhaust side mainly because of my very modest 250hp goal. Otherwise I plan to mate the Frankenstein head mini-me style to the Z1 block, and use a 1st generation HR-V transmission for its far more appropriate gearing for the canyon roads I like to drive on. If I've grasped anything from your other posts I feel there is plenty of room with the HR-V transmission to play with making the ratios closer. I've zero need or desire for the car to go faster than 116-120 in 5th gear. More important to me is being able to stay between 4500 and 6500rpm when really pushing the car. The HR-V transmission in 2nd and 3rd will easily manage this in stock form at the speeds the car is capable of through most every turn I experience. I really appreciate the information you've shared over the years, I'd love to show that appreciation by going through you for any transmission mods I may find myself wanting to do. |
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