[hondaracer13]

What is the best head non Vtec. I want something to put on my Y7.
I dont want to do the Vtec. To much work or to much to screw up I mean.

 

[Honda4VW]

Use the Y7 head

 

[DOG]

Y7 is probably the better of the non-vtec heads. Bigger valves, smaller cc chambers. With work though both can be made better. Only bad thing about the y7 head is aftermarket parts.

 

[pearl62]

some of the other sites have yalked about this... I've also heard it from a couple engine builders too.

The Y7 is the same casting as the Y8, so the port shape will be the same, ie. a slight cant to one side to help produce more swirl in the chamber for better low-end performance (up to ~5500). With porting, it can gain back some top-end. It shares the same valve size as the Y8 at 30mm int. and 26mm exh..

The A6 head on the hand, shares the same ports as the Z6, which have symmetrical ports with a straight shot to the valve. These flow much better a higher rpms. In stock form A6 heads have 1mm smaller intake and exhaust valves though (29mm int., 25mm exh.).

So, if you were going all out and building a race motor, I would go A6 with bigger valves. For street, I would just port a Y7 head (I did!). It cheap too!

 

[pearl62]

Only bad thing about the y7 head is aftermarket parts.

What's missing in the aftermarket? Y8 and Z6 valves can be used in a Y7... The springs and retainers are also the same. The Cam might be the only thing missing, but regrinds are available. If a few more people start working on their Y7's and realize they have potential too, maybe Crower, Zex, etc. will start supporting the Y7 also... Gude, Delta and others have been supporting the A6 and Y7 for some time.

 

[DOG]

Yeah there are a few like good old DeltaCam and Gude. But not many. Cams are what I was talking about as far as aftermarket. I think that Exo-speed may have one soon.

 

[Deck]

y7 has the roller-rockers right? Seems like that would be the ideal setup due to less friction. Also, if it is the same cast as the y8 shouldnt it be possible to go VTEC with the y7?

 

[slebidia]

Let's correct some info here.

The Y7 is the same casting as the Z6. Want pics? I'll get them. The Y7 uses Z6 valves, springs, etc. The only thing missing is VTEC. It shares nothing with the A6 except for fact that it has 4 valves. Oh and the Y7 head is not a roller rocker head.

The A6 shares nothing with the Z6, Y7 or Y8.

 

[DOG]

Yeah the y5 is the head with the roller rockers. And yes they are completely different design between the a6 and the y7. 34.6 cc y7 chambers and 38 cc a6 chambers. The z6 head and the y7 port runners, or whatever you want to call them, are the same. As far as being the exact same casting as the z6 except for vtec I havent ever heard a confirmation on that , but I believe you are correct.

 

[slebidia]

Well I didn't mean exact same. Same port shapes and Same combustion chamber shape/volume. Valve spacing is the same, valve size is the same. The good thing about the Y7 is that "normal" distributors will bolt up.

 

[DOG]

As far as basic design, where does the y5 stand in comparison. I know the chambers are different, but what about the valvetrain? Comparable to any other D-series heads?

 

[slebidia]

I have no on-hand experience with the Y5. I'm been trying to find one to play with for awhile. As soon as anyone see's that I'm interested in one though the price suddenly becomes 4 times what I'm willing to pay. I've heard that it's a pretty proprietary design but I don't trust anything I hear on the internet.

 

[DOG]

The most Ive gotten is a few pics of a head that was for sale on ebay. It had been PnP'd and worked on by JG. At least , that is what the description said.

 

[slebidia]

Odd chambers. Thanks for the pics.

 

[Guest]

Y7 and Z6 are the same I would believe..cause I'm running Z6 valves in my Y7.

 

[Guest]

I have heard the best higher rpm head is the a6 heads. They are the same heads as the d15a2 = very cheap or free!!

 

[Guest]

im still trying to sort out wich head is a roller and wich is not. might as well ask wich is the best of the rollers. thanks.

 

[builthatch]

y5 is a roller, right?

 

[DOG]

Yes it is the y5 with the rollers.

 

[S Q A D]

do yall think... a y7 head with a port and 3 angle valve job, y7 regrind cam from delta ... a y8 manifold , gsr t/b and maybe some y8 valves and retainers with a 98 y8 ecu would be a good setup for street turbo ??