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Need cyl head work - who do you recommend?


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I'm in central VA, in case that makes it more convenient (but am happy to ship the head), and I am looking for an engine builder/shop to do a general check of valve and guide wear and a to perform a quality valve job. The head was originally redone by the guy that did most of Malvern Racing's machine shop work. It has Manley stainless valves (1mm larger intake) and hardened seats already. I've spent a bunch of time over the winter modifying the combustion chambers and porting it and a tripple manifold in preparation for putting in a high lift/duration cam and tripple mikuni's. So, the work I'm looking to have done is likely just a valve job and possibly the cam installation. I am looking for first class work.

Who are the go to shops for Nissan L-series these days?

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Can I just ask, was the head modified in any way other than the o/s valves and valve seats?

You said you spent a lot of time modding the head yourself. I'm hoping that you didn't 'undo' any of the good work if the above question was answered 'yes'

Why don't you try your head with the same cam after your porting? Then you're able to assess how much power you've added to your engine with just the porting mod. Porting the head AND changing the cam, you'll never be certain which modification is really contributing the most to your power increases. Could be the porting was dud and the cam good but the net effect is little improvement. See where I'm heading?

I'm not wanting to rain on your parade here but I like the response the engine retains with stock ports. The idea of changing cams is great because for whatever reason you decide a cam is too big, just put a smaller one in its place. The problem I see with head porting is that if the ports are too big, well, buy a new stock port head and do all the work that's needed all over again, not including ripping off the old one and putting the new one back on. Any guy with an old skool SBC would love to be able to swap cams as easily as we can. :paranoid:

Just thinkin' out loud mate.

Good luck with your project.

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Thanks for that John......Carlos at Citizens Machine (Highland Springs,Va. ) is the man with Z heads......35 years as a machinist. He owns the shop and does a couple SCCA racers. He'll do a beautiful job for you! PM me and let me know what you're thinking about as far as mods. His number is 804-737-9211. He's a little hard to understand on the phone, but a master machinist! Guy

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OZ connection, understood. For all I know the porting I'm doing could be a big mistake or done incorrectly, but I'm changing the car's purpose. I have several other cars now and my Z has become almost exclusively a track time car. In the last year or so, I've done 3 track events and driven it on the street once.

The cam that is going in is pretty radical. From posts on Hybridz.org, it seems that several believe my 10.1 compression won't be adequate. We shall see. I am also changing from the stock SU's and stock manifold to a long Cannon manifold and tripple 44 Mikuni's. The porting has to match the cam and the carb changes... So, before and after of just the porting isn't really important.

All the work that had been done to the head previously has remained untouched. Basically, it was just new guides, seats, and valves with some smoothing of the bowls under the seats... I had previously matched the intake ports to the stock intake manifold, with porting limited to about an inch into the ports.

Now, I have added some combustion chamber work to reduce the restriction around the restricted flow areas of the valves against the combustion chamber walls, enlarged the stock ports to 1.545" (while moving the openings up as much as possible - staying away from the bottom of the ports).

I've also ported the manifold extensively... No flow bench and not a whole lot of info out there on what exactly to do - understandably I guess. We'll just have to see how well (or not well) it works.

Diseazed, I'll send you the pm.

Edited by inline6
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