theczechone

I'm in

So a few times now I have tried to figure out how to add images directly from my phone (iPhone SE) into a private message. There seems to be no “upload” option. thanks for any help

I’ve got a set. Pm sent

I got my cam and components through Dave Rebello at Rebello racing. I supplied a cam for a regrind and rockers and he sent back a fresh ground cam, lash pads, outer springs, and reground rockers for 495 shipped. i got his street cam but he has many variants he can suggest. Good luck.

@TimZ have you looked at the part's since you installed them? We used ceramic coating on development engine i worked on, the coatings we used were significantly thicker(0.5-1mm) and chipped off. This engine was subject to high firing pressure loads (yes, higher than yours Tim) and higher temperatures so there was more thermal growth on the substrate(piston) which essentially caused the cracking. I do think that a chipped coating could get trapped by the ring and score the bore or get trapped by the valve and mess up the seal. But i don't think these failure modes are going to cause a huge detriment to performance.

I have my set of SUs, came off my running 72 240z. It was mounted on a L28 though. Message me if interested

I actually use the stock 280z temp sensor in that location as a plug lol. The threads are bspt or bspp. I think 1/2? Don’t quote me on that

Fair enough franky240z, https://www.rhdjapan.com/kameari-cast-racing-piston-kit-l28-l30-l31.html their cast kit is even cheaper at $770+shipping, same as forged from ross racing by the way. I wonder if you can select your pin height, their advertised pin height is 29mm. With a stock L28 crank you would need the FJ20 rods to make it work.... additional 800 or so... I've been through the ringer on this. boring out to 89mm bore if you don't have a stroker crank will just get expensive. Even used parts from yahoo japan are pretty expensive. https://page.auctions.yahoo.co.jp/jp/auction/x567154406 FJ20 Rods https://page.auctions.yahoo.co.jp/jp/auction/b336457926 89mm pistons I have heard stories of great deals on engine parts but i wonder if i'll be so lucky

Don’t forget shipping from Japan

would really love to have another 3.1L but the prices these days make it difficult. for headgasket, there is always cometic, but that's not cheap either

So, i am biting the bullet and getting ready to hide my car expenses from the wife for the winter. Meaning, I want to rebuild/build my engine. I'm sure the question has been asked a bunch before but I am looking for a cast (hypereutectic) piston to stuff in an L28. I have no need to go forged, I want to keep my engine speeds below 7500 with peak power happening right around 6500 and I am naturally aspirated. So it is hard for me to justify $800+ for a set of forged pistons I will be overboring my N42 block, oversized 81zx flat top pistons are only available up to 87mm bore. Also the only ones i find are ITM? Quality is in question? Is there another option that i am missing? thanks for your input guys.

if you want more info find Steve Bonk on facebook. I dont think he is on HybridZ but i think he bought the rights to the Potter grinds from Don Potter's wife after he passed. He would have more info on it.

are oem valves still available from Nissan? What happened with your SI valves?

FWIW i spoke with Dave Rebello and he seemed to think that the valves would be fine as long as used with bronze guides. Great guy, I've only bought a cam kit from him and he has been super helpful with every step along the way.

Interesting, I did source bronze guides. Perhaps i should check what the proper clearance needs to be. The factory guides were bronze and the factory valves were stainless so there is no change of material so i would assume same clearance is expected. I will take some measurements on the valves when they get here and compare to the stock ones.

@HuD 91gt i'm getting new guides installed , i will provide the valves to the machine shop so they should be able to size the guides after the installation to the new valves. Is the stem diameter on SI valves larger than stock? Any issues with valve seals?

Ended up ordering from SI Valves. New stainless valves available in 44 or 46 for intake and 35 or 38 for exhaust. I went with a stock size, and they were 10.50 a piece! for a shipped priced below 140 for the set!

So i am rebuilding an N42 head with some mild porting, it will also get a street cam which needs new springs(outers only). I'm installing new seats and guides, should i also spring for new valves? Or can i just get the used OEM ones cleaned and inspected? Do the Z valves experience a lot of keeper groove wear? If i choose the replace route, what are good manufacturers? I see ferrea offers some nice valves but the price is high ($420 on their website, $330 on ebay) Datsun Spirit Offers their set for $230 which seems fair... and then we have the ITM and DNJ valves that are questionable for $8/piece for a total of $96 from RockAuto.... Is there someone else?

DSI uses Jenvey throttle bodies that can be sourced here : https://foxinjection.com/collections/dcoe-throttle-bodies-91mm-long/products/thpxxi-th-body-45-50mm-pair there are also different versions other than 50mm

You can generate them with DesktopDyno it's a simple math based program but it can show trends. It's not perfect but you can learn a lot about the effects of changing components on your engine.

I would need more info than just two points and at what vacuum pressure were these flowed. would also need more cam info to define the profile. need to know crank rotation for exhaust and intake valve events. This is the flow numbers i have found and i am using

If you have some port flow numbers for stock and ported heads I’ll gladly update my plots. But this is the numbers I was able to find. keep in mind that larger cam will make less torque but peak will happen at higher engine speed therefore generating higher horsepower. Big cams benefit from high compression ratios, 10.5 is relatively low. So unless you’re changing other components the net benefit of a larger cam is low and kills drivability.

Talk with Dave if you are thinking of going with his cams, he's quite helpful. As far 540 or 480 lift the difference will be negligible unless you have done quite a bit of porting. And it's a small gain for a lot of added complexity. I just got the 480 cam because i am doing an amateur port job and just learning as i go, plus less than $500 for cam regrind, lash pads, springs, and rockers resurfaced... tough to beat that. BTW this is plotted on 87mm bore 79mm stroke L28 with 10.5 static CR n42 stock flow n42 ported flow

I have a few available, these would be oem 240z units. I think all of mine are series 2 style with the S shape. I can check the threads on the ones i have.

Thanks guys. Have one to send to Dave.