Stealth-Z
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Posts posted by Stealth-Z
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im trying to get 11.25:1
lol
i'd love to buy them from you for a good price, but i don't think they'd have enough dome height on them. they need 16cc atleast, or i'd need to chop the head quite a bit.
then I would have to machine some reliefs in the pistons too =/
The pistons he has have a 16cc dome. I have another set identical to them except they are 0.020 oversized.
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You have been doing some homework! Mine will be using the Dayco 94407.
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Here is a link to classiczcars photo gallery. http://www.classiczcars.com/photopost/index.php You might have to register and be logged in to view them. RB30 SOHC and DOHC's fit with the cross over intake without interference problems. The Castlemaine mounts should work with no problems.
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That is an NA motor. You can see another set of pipes next to the TT's. Mine had Blitz blow off valves. Look closely at the fuze block.
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Tensioners are the same as the Z31 V6's. I have 2 new ones and compared them to the RB20 and RB26's. Same dimensions. Coild springs are identical as well. Bought them new as well. Tensioner stud was the same on all my RB blocks.
My build has been a few years in the making. Most of the headache has been with the pistons. I could have had it up and running a long time ago. But, I wanted nice precise specifications. Plus it is a good learning experience.
Wait till you start getting into the RB26 head rebuild. Chances are it will need exhaust valve guide replacement. Then there is the adjustment shims. Found out they are simular to the way older Jaguar heads are setup. Very time consuming process to get the proper clearance.
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so using the specs of the Arias pistons i've listed, what can i do to get a 10.5 or thereabouts compression ratio, with 64 cc of combustion space on the head? u think maybe i'll have to deck the block and then machine the crowns of the pistons?
For a calculating program I am using this one from Wiseco.
http://www.wiseco.com/Calculators/HelpfulCalculators.xls
Here are the numbers I entered.
Bore Diameter 3.406 Inches
Engine Stroke 3.346 Inches
Head Volume 64.00 Cubic cm's
Gasket Bore Diameter 3.410 Inches
Compressed Gasket Thickness 0.0590 Inches
Deck Clearance 0.0000 Inches
Piston Effective Dome Volume -13.00 Cubic cm's
You can start juggling numbers around to see what you get. You could deck the block to have the pistons run out of the bore by say -0.01 Inches. Use a 1.2mm (0.047 Inch) head gasket. Shave some off the head to get it down to 60cc chamber volume and you end up with about 10.5:1.
You would have to measure valve clearance to see if flycuts would be necessary. Then you change parameters again by removing material off the pistons.
The resulting quench value would be .037. Sounds good having it that close but you have to consider piston rock motion. Higher RPM's along with different tolerance stretching and deformation could run the piston right into the head.
Isn't striving for precision great? Using the 16cc dome parameter on my new pistons would yield a CR of 11.08:1.
I have learned alot from the guy that rebuilt my turbos. If Wiseco had not come through, him and I were going to work up a custom set of JE's. There is a lot of different design factors to take into consideration. There is no such thing as an off the shelf precise compression ratio piston.
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Woah, totally skipped that post by accident.
Which wiseco set are you using? the compression height of 1.260 means i might have to deck the block 0.020 to get a reasonable quench, as the RB30 pistons are 1.280. the arias pistons i was considering are these:
Suit RB30/25
p/n= AP332105
13cc dome top
21mm pin
1.280" compression height
Only stocked in 0.20 thou oversize (86.5mm).
COMPRESSION RATIO 9.5-9.8
I have HKS 9.15/264 cams and cam gears coming with the RB26. That's the highest you can go without getting excessive valve float on stock springs.
This is why I'm trying to decide whether or not using the 13cc domed pistons to get 10.11 instead of using the 16cc wiseco's to get 9.8 is a better idea.
I could take about 0.040 off the head, and get down to 10.5 or even 10.75 compression ratio, but I'm not sure if the 9.15 mm lift is ideal, again... flycuts come into play..
And ARIAS is of NO HELP WHATSOEVER (I hope they are reading this). I've emailed them twice and got the same answer with two different prices. "Custom piston required... XXX amount per piston"... BUT NO HELP with specifications and such.
Also, ARIAS said they have tested over and over again with multiple heads from RB26's and come to the conclusion that it's more like 64.5 cc's or so. But others say 64cc... so i'll re-start my calcs and stick with the 64 this time.
I'm using Desktop Dyno2003 software, as well as some websites to do compression ratio calculations.
The pistons I have coming are custom jobs. Here is a thread where I talked about the first measurements. Wiseco seems to have admitted there was a mistake in their calculations and the order spec. They have since remanufactured them to the parameters I mentioned above earlier.
http://forums.hybridz.org/showthread.php?t=119593&highlight=rb30
My block has a 4 thousands difference between the front and back. Pistons with a compression height of 1.260 sit in the front of my block by 18 thousands and 22 thousands in the back no. 6 cylinder. It will require a minor adjustment on the deck level.
Once the pistons arrive I can make more detailed measurements. I am assuming Wiseco figured a -0.020 deck clearance along with the RB26 head measuring 66cc's and the stock head gasket of 0.059 to get a proper CR of 9.1:1.
Arias has more accurate measuring devices than I do about the chamber cc of the RB26 head. A stock untouched head may be 64.5cc's. Once you start grinding valves and surfacing the head, those parameters change fast. Both RB26 heads I have came in at 64cc of light oil. This was after they had been hot tanked and pressure tested.
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What program are you using for a compression calculator?
I have a set of Wiseco's on the way that have a 16cc dome with a compression height of 1.260. If I deck the block to get a zero deck clearance and use my RB26 head chamber measurement of 64cc's along with a head gasket thickness of .059, I come up with a CR of 9.79:1. .059 is what a stock RB2x head gasket measures out at.
This is to high for my build. Once the pistons arrive, I will start evaluating modifications to the pistons to get the CR down to between 8.5 to 9.0. My research still continues on how close of a quench value to persue. Getting between .040 ~ .060 seems to be ideal.
Getting the pistons close to the head brings up possible issues with the valve clearances. That would mean machining flycuts into the pistons. The stock cams should not be a problem but I want to measure first. Future plans would be using cams with about a 9.15mm lift and a duration of 260. I have an HKS exhaust cam to do some peliminary measurements with. It is 9.6mm lift with a 264 duration.
A set of Nismo R32 turbo's will be used on the motor. I had them rebuilt so they will last for a while. The plan is to run a max of 16psi on them. They are .60 /.64.
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I bought the 2+2 for this reason! I think it looks better than the Coupe ( before I get All the HATE mail, IT'S JUST MY OPINION!!!!) and I know I will got to hell for this but the coupe is too short for me? The 2+2 looks sleeker when compared to the coupe.
Guess I will meet you in hell one day as well! I see the 2+2's as beeing more sleek in design. This is the one mine is being modeled after.
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What other specs are you after?
I am getting good with measuring piston / Compression Ratio combinations. My goal is to get a tight quench to start with. My new pistons should be arriving soon so I can start remeasuring.
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I have one sitting in the spare room. Quality is not bad for the price. It does need some finishing work. It is not a bolt-on replacement without more re-enforcement. Definetly a light piece though.
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It is about a 2 hour drive for me to get to thier house in South San Francisco.
After seeing how it is done, I have these grand ideas of making door skins for mine as well. Time is keeping me from learning more.
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Are you saying the guy who made the Primmadonna Z's is mentoring you?
Yes
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BAH! Stateside Door Panels...
You tease, you!
Read the description on these door panels after the asking price shock wears off. Not for us 2+2 guys though.
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I would love to go back to Okinawa. In a civilian capacity instead of military though.
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You may have to sculpture your own flares. I am starting to experiment with fiberglass. My mentor is one of the most detailed oriented I have ever met. Watching him work is amazing.
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Hi guys,
I keep forgeting there is a 2+2 section. Anyone have an interest in some NOS white door panels? My Z has power windows and I am going with black interior. These are to nice for me to take out the fuzzies or dye black.
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The drivers side floor board in the first photos is with the tar mat removed by the previous owner. He started scraping off undercoating all over it. We took a wire wheel to common rust prone areas. There was a small pin hole in the passenger side dog leg. I took a grinder and cut out about the size of a quarter to look. That was the largest area of rust. The shell is very solid.
We will be parting it out. The shell is free to anyone that wants it. We have a bill of sale from the owner. It was last registered in California in 1995.
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Yea I would if you would ship it! Just got my 2 to the shop both need alot of work. Dose this car have a title?
We have a bill of sale from the previous owner. It was last registered in 1995. Getting a CA title would not be a problem.
Tomorrow we will do more indepth checking of the body. We are going to jack it up and poke around.
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Hi guys,
I have a slight dilema here. A few hours ago my friend and I bought a 1970 240Z parts car. The VIN is in the 12,000's and it has an automatic with a SU carbed L28.
The dilema is about cutting it up. Check out these photos.
http://www.fairladyzg.com/images/240z/index.htm
This has no major rust. There is not even minor rust we have found. Floor pans are intact along with the battery tray. The primer is showing surface rust. Would anyone be interested in the body? It would be a shame to cut it up.
By the way, the Blue 1975 280Z, funny thing there. I jacked it up and the rubber insulators were rotted away. Not something I have seen happen before.
Ultimately I need to stop looking at criagslist!
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Cool find. I have been on the hunt for another one for some time now. Finding one made with a little bit of quality is the hard part. They say you get what you paid for. But I want to find one without having to sell a kidney!
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autoxzx,
You are not alone with this problem. My stock 78 gets hot during idle. The higher the outside temp, the closer to 250 it gets on the gauge. Soon I will find out how it reacts to 100 plus degree Sacramento Valley temps.
Here is what I have done so far.
Replaced Radiator, water pump, and thermostat.
Interesting thing is it does not use exessive amounts of oil or coolant. All the spark plugs show normal sediment patterns.
Next on my list is the temperature sending unit.
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My RB30 oddesy began in 2004. It was offered on ebay. Here is a breakdown of what it cost and the process. This is what the break down was then.
Series II non-turbo short block off ebay
(block, crank, rods, pistons, rear seal, and beat up oil pump) $305.00AU ($218USD)
Shipping and handling from Australia $304.00AU
Total $609.00AU or $439.20 US Dollars
The block was picked up from the sellers door and loaded into a container consigned by Brennan International
Brennan International Shipping Company charges into Port of San Diego
Documentation $50.00
Terminal Handling Charge $45.00
Chassis Fee (No idea what that was) $2.00
Port Security Fee $25.00
Customs Exam $19.55
Total to Brennan $141.55
St. George Warehouse of Oakland
Forklift $35.00
Customs Entry Fee $50.00
Documentation Fees $5.00
Handling In/Out-General $35.00
Total to St. George $125.00
Now on top of all the above, I drove from Sacramento to Oaklnd to pick it up. That was a 200 mile round trip. So figure about $25.00 for gas. The St. George customs entry fee was for filling out a single piece of paper that needed U.S. Customs clearance signatures. I had to drive a few miles to the customs office to get it signed. No big deal.
As you can see, it ended up costing me around $730.75. Figure about $500.00 in shipping alone. If you have to ship further inland, figure more on top of that.
All the above should give a good idea of what is involved. Shipping heavy items can be troublesome. RB30 motors may be cheap and plentiful in Australia but remember someone has to go through a lot of time and effort to ship it.
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No...As the man of the house was coming in the front door I was squeezing thru that Damn bathroom window. That gets old. It was time for a change...
LARRY
And with a nice Supercharged Z you made a quick getaway!
Larry, you will be missed in the old valley area.
got my hood..need your thoughts
in Body Kits & Paint
Posted
The one I received from up22 a few years ago looks better. It is still sitting in the spare room. Sorry to see thier quality control diminish.