Engine Blueprinting Spec Sheets

[Careless]

Hey everyone, I'm about to send my block to my machinist in the following week, and I've been taking measurements of my clearances and such and putting them into an excel sheet, as well as taking measurements for the RB30 main girdle to put together an RB30 main stud kit.

 

I know there are about 4 AUS retailers that have ARP RB30 kits for the mains, but after talking with Al @ ARP, he assured me that If i do the measurements, and feed him the results, he can find the same bolts that these 4 distributors use when ordering and putting together their own kits. He said i'd save an Ass-load on shipping and inflation, too.

 

Should I end up finding out all the proper specs, I will either post them here, or make some kits in a HybridZ group buy, as no one in North America stocks these kits, and these engines are getting a tad more popular.

 

The only thing left for me to do is to calculate thread pitch/diameter of the bolts/threads in the block, as well as the depth and the thread recess.

 

Now... I've been putting these calcs into an Excel spreadsheet for easy adjustment, as well as the blueprinting specs that I've been doing for the engine clearances and such.

 

Does anyone have a template that they use for themselves and wouldn't mind sharing? Or am I the first person that's decided to do it this way, rather than writing it down.

 

I figure having my own specs before giving it to the engine builder is a good way of assuring that if I ask to compare his to mine, and they're within reasonable tolerances (tools vary), that I can do this myself in the future, rather than pay someone to do so. As well, it assures me that he'll definately do it

 

anyone have any crib sheets?

[Stealth-Z]

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.

[Careless]

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.

 

Hi Stealth-Z,

 

Ideally what im looking for is a workflow sheet of what people usually include in their measurements. I bought an engine blueprinting book and read it cover to cover, and it's mainly for pushrod v8's like sbc and sbf, but I need some OHV blueprints that most people look after.

 

I also need to get the proper quench area on my RB30.26 and I might be ordering Arias pistons with a 13cc dome for 10.11 compression ratio, but I'd like to get a tad higher, maybe 10.5.

 

But I would settle for around 10.2, knowing that I can apply a small amount of pressure (5 - 10 psi) with a high flowing turbo/inter-cooled setup that will be compact and provide the already stout engine with about 400 hp, which should be enough for the next couple of years.

 

I'm actually thinking of readying a tri-turbo system too if i can manage to get it to fit, with some hood mods, i'd bet.

 

but for now, 280 - 300 N/A hp is my goal, and I've got the stout spool rods, as well as some SS 308 head flanges to make a nice stepped tube exhaust header. I figure if I can make a tight as possible quench area, with a thin gasket, perhaps I can lower compression considerably with a thicker gasket, while retaining a reasonable quench if I decide to ante-up the air feed to the cylinders.

 

I'm going to wait for my RB26 to come though, so I can use that to guage the proper thickness for gasket and height for pistons.

 

the RB25.30 arias pistons seems to be choice right now though, without serious decking (was going to use VG30DE Pistons), which have a shorter compression height.

[Stealth-Z]

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.

[Dragonfly]

Ideally what im looking for is a workflow sheet of what people usually include in their measurements. I bought an engine blueprinting book and read it cover to cover, and it's mainly for pushrod v8's like sbc and sbf, but I need some OHV blueprints that most people look after.

 

You probably have the same book that I do, in the back it has pages that you can use to "pen and ink" all your data/specs which is how I did mine. I realize that the book is geared toward pushrod V8's but most of the critical dimensions exist in OHC engines as well. I did also use the "How to Hot Rod and Race your Datsun" book to provide me with additional info on OHC engines. With all that said if I were to do this on a spreadsheet I would probably copy most of the info from the blue print book following that format then add any other dimension that your engine has that is not covered. As much of a PIA as it is one of the important things is the more measurements you have the more accurate everthing is.

 

Last comment "if" your measurement tools are calibrated and the shops tools are calibrated you should not differ in measurements by any more than one increment (the smallest increment on a given tool).

 

Dragonfly

[Careless]

Last comment "if" your measurement tools are calibrated and the shops tools are calibrated you should not differ in measurements by any more than one increment (the smallest increment on a given tool).

 

Dragonfly

 

Yeah, my tools are mostly digital calibration type. By far not the best tools on the market, by any means.

 

However they've been fairly accurate in comparison to a friend's more expensive set.

 

And I measured the accuracy of my feeler guage with my micrometer, and it's spot on too.

 

Thing is, I've seen some people how toss their tools on the workbench like it's not gonna do anything to them. And I'm hoping my engine builder isn't one of those people, because he seems like he knows what he's talking about.

 

 

And yes, my book is the "Engine Blueprinting" book with crib sheets at the back. I guess I'll use those as a start. =)

[Careless]

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.

 

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.

[Dragonfly]

Careless here is a test that you can do to verify your tools to each other and if the machinest will let you (big if) you can verify his tools to yours. Get something like this:

If you want you could make something like that from a NEW ball bearing and a wooden dowel by epoxying or super glueing the bearing to the end of the dowel. Once you have your "standard" take each of your measuring tools and measure the bearing, take at least four measurements on each tool at different points on the measurement surfaces and write down each measurement. It doesn't matter what size the bearing is as long as it is small enough to work in each of your tools.

 

You will probably find that some of your readings are different from one point to another on the same tool, that indicates that you have an error in the parallelism of the measuring faces of that tool, if that differance is greater than 1/2 of the smallest increment of the tool (or one of the least significant number on a digital readout) then that tool should go in your "measuring wood for the garage" pile. All of your tools should be within one increment of each other when you compare your readings, the tools of the machinest should be within one increment of each other as well and no greater than two increments from your tools. Be aware that ambeint temperature can affect these readings so try to make sure that if you check the machine shop tools the temp is as close as possible to the ambient temp when you checked your tools.

 

If you are anal enough to care the thermal coeffecient of a typical precision bearing is 6.5 millionths of an inch per inch per deg. F, which means that if it is 80 degrees when you check your tools and 70 degrees when you check the machinest tools and you are using a 1/2 inch diameter bearing you will be off by almost one increment (on a high quality micrometer).

 

Dragonfly

[Stealth-Z]

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.

[Careless]

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.

 

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?

[Stealth-Z]

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.

[Careless]

Isn't striving for precision great?

 

Thanks for taking the time to type up your response.

 

At this point, would it just make more sense to wait for the head to arrive with the cams, and order pistons later?

 

I guess I should set aside the amount left which I need to pay my engine supplier, and buy the other necessary goodies, like the pan, pumps, and tensioners.

 

I got a gates powergrip GT2 150 tooth belt, to use stock idler and tensioner location, but I'll require two tensioners.

 

Which brings me to another question (unrelated to the thread, but i'm not gonna bother making a small thread to clutter the boards for this)...

 

so... I have the 26 head and the 30 block. Do i use 26 tensioners or 25 tensioners? I was under the impression that mostly rb25 stuff was bolt on with the RB30 block. Is the tensioner stud for the 26 any different, or is it the coil that is different?

 

I've asked elsewhere and everyone says "ill check it out", but they don't. I understand, people are busy =)

 

[Stealth-Z]

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.

[Careless]

Tensioners are the same as the Z31 V6's.

 

Wait till you start getting into the RB26 head rebuild.

 

so they're the same? weird.

nismoparts.com stocks 20/25 and a separate 26 version =/

 

RE: the head.

 

I hope that the oil starvation didn't cause any ♥♥♥♥-ups for the top end of the motor, as it seized due to a bearing failure down below, which is the result of monsieur oily-pump taking the high road. But I am getting a good deal on it, and the sensors and everything else (HKS cams and gears) make it worthwhile.

 

sadly, I am not getting a transmission with the engine, but it's ok. It will be a long time before it makes it's way into the bay.

 

my machinist said he'd recondition the head, and give it a 3 angle valve job, and adjust all the proper parameters for 300 CDN, as well as 500 CDN for port and polish of all 24 ports, as well as port matching, Then it's upto me to make the ITB setup using the factory ITB's with elongated trumpets that curve up and forward a bit. I mentioned RB30 to him and he hadn't a clue, but when I said skyline motor, he said he's worked on a couple with excellent results, and no failures yet.

 

So should In anyone's opinion (those reading this), should I go ahead and buy the water and oil pump, as well as a gasket kit and oil pan setup, with two tensioners (pending explanation of nismoparts selection).