Gerg_R31

Ha, yeah i sleep, just woke up too not much left to finish

And last update for the night, everything is washed and ready to be assembled Washed head Washed parts and i decided to do a little teaser

Its the formular for how to properly work out your exact static compression ratio. a lot of the numbers in the equations were measurements in millimeters http://www.skylinesaustralia.com/forums/topic/378823-engine-internals-comp-ratios-general-info/page__pid__6104330#entry6104330 i wrote that up a while ago, should help give you a better understanding

In total 52 thou ground off, its now at 61.2cc's all deburred. machining is now complete now to give it a final wash, put cams in, mark out drill and tap for relocating the tensioner, pull head off, put valve train in, chuck it on torque it up, put cams in and my bit is done

There's also my r31 with NOT p plate friendly mods, 1300kg 225.6rwhp or 1hp per 5.76kg, she is quick when she isn't breaking pressure plates/ slipping in the mid revs The new n/a falcons are pretty quick from factory too

Well i took another 15 thou off, im at 62.1cc's ok the comp ratio maths SV bore x stroke 86.5 x 86.5 / 4 = 1870.5625 x 3.142 x 85 = 499,571.13688 / 1000 = 499.57113 (SV) Engine cc's 4.99.57113 x 6 = 2,997.42678cc's / 1000 = 2.99743 litre CV Head gasket 88 x 88 / 4 = 1936 x 3.142 x 1.2 = 7299.4944 / 1000 = 7.29949 Deck to top ring 86.5 x 86.5 / 4 = 1870.5625 x 3.142 x 6 = 35,263.84425 / 1000 = 35.26384 85.65 x 85.65 / 4 = 1833.98063 x 3.142 x 6 = 34,574.20284 / 1000 = 34.5742 35.26384 - 34.5742 = 0.68964 Piston dome volume 85.65 x 85.65 / 4 = 1833.98063 x 3.142 x 1.397 = 8,050.02689 / 1000 = 8.05003 Volume around dome measures 1.8cc's 8.05003 - 1.8 = 6.25 piston above deck height 85.65 x 85.65 / 4 = 1833.98063 x 3.142 x 0.1016 = 585.4565 / 1000 = 0.58546 7.29949 + 0.68964 - 6.25 - 0.58546 = 1.15367 + Head cc's 69.6 + 1.15367 = 70.75367 + 499.57113 = 570.3248 / 70.75367 = 8.06 :1 Also did 64cc's = 8.67:1 62 = 8.91:1 60 = 9.17:1 61 = 9.04:1 61.5 = 8.97:1 61.3 = 8.99:1 61.2 = 9.01:1 So that how i worked out it needed between 61.2 and 61.3

Yeah but there is a good chance only 1 in 50 people will actually understand the details, which i have skipped some detail (i can add all the maths with all working out in as well if you like, would be a very long post ) Oh and I've ground 29 thou off so far, re cc'd it and its now at 64cc's which would make it 8.67:1CR (before with the 69.6 would have been 8.06:1CR)

Head cc'd at 69.6 cc's, aiming for 61.2 - 61.3 cc's 10 thou grind

Id assume the stock girdle strengthens to front to back flex, and this would strengthen the side flex but I'dsuggest to speak with platinum racing for more details on it, im aware they have 2 products 1 is the brace (purple) the other is a brace and awd conversion (blue) Sump rail and girdle are milled for exact height, the edges of the girdle are machined at an exact angle on a mill, 32 holes are drilled and tapped on the sump rail and girdle for it to bolt onto

And the bottom end is done (minus the tensioner relocation)

Rods torqued to specs with arp lube and checked for size, up to 1 thou smaller, quick hone and now they're on size

Paint and Welsh plugs

Matching oil drains and water jackets on block and head to head gasket, yeah go for it but matching the gasket to the block cylinders is a bad idea, (bores need to be straight no taper no ovality) yes it has a chamfer on top of the bores, but they're only purpose is to help get the rings in during assembly matching the chamber to gasket, enlarging the chamber, removing both squish pads will reduce the quench (when the flat spot of both piston and head meet in pushes the last of the volume into the combustion area for a more "complete" burn) removing the intake squish pad has been done a fair bit but you will find there is still material between the chamber and gasket then there is the extra volume that was just added, can you garantee that you haven't reduced the compression ratio dramatically? Removing all that material will put extra strain on the firing ring on the head gasket, all the material being removed up to the firing ring will encourage the gases to escape, consistently blowing head gasket

f**king school holidays aye i agree with mad082 what's the point in having all that power if it can't be used, n/a or not any motor needs to be built around its main purpose and be practical Plus im a strong believer of response/ torque is what you should focus on and the power output is just a bi-product. With the nos idea, to "just whack a nos kit on" is going to kill any motor that is not prepared for it, some stock valves will burn out that never would in normal conditions. cast pistons will crack or melt, forged pistons will eventually melt, "tuff" coated forget pistons will stay coated from 6-20 shots (varying depending on how much is used) leaving a bare forged piston, and im sure there is more in areas i don't specialise in (wow we did go off topic a bit didn't we)

I hope your talking about the water jacket and not talking about the combustion chambers

Posting for updates, oh hey look there's one now Block getting kero washed Wondering what Pete's block would look like with a nitto 3.2L crank Dummy assembling to measure piston to deck height (and check main tunnel clearances) (all were exactly 0.0015" no ovality) (perfect only 0.009" to grind off for 0 deck height) now to wash the block again and paint it while i continue to reset the tappets after having to correct and redo just about everything on that head

surface rust / heat stains, though they do look a little porus (as in metal sprayed then ground to a large size, not ground from a billet, cheaper to manufacture) but thats all i can get from a picture but i wouldnt stress about them not looking pretty if you cant feel it at minimum id recommend a Linish as micro-polishing is a completely different process which takes about a week (but if you got the coin id recommend to get them micro-polished) this is coming to you as first hand information from someone who is qualified in the engine machining industry (and go easy on mafia he knows his stuff) linishing http://image.turboma...haft+polish.jpg micro-polishing http://media.photobu...d/esp_armor.jpg

Ty Yeah i was thinking about the e85 but no one near me sells it, pros of the haltech is i can get it tuned to the e85 later

Lol been off P's for about 2 years which was when this motor went in

What was their issue? Did you get it retuned? Yeah i agree the vct cams will give better results

Got Vl box, single piece tail shaft, and as of this morning no clutch grr probably shouldn't have gone for a drive through national park on the weekend

Ill weigh up the rd block and rb30 then the rd after its filled the other benefits is the rd blocks have oil squirters

"procams do require additional valve train upgrades" this was not directly mentioned or aimed at the rb motors Thus meaning if you run hydraulic lifters the procams will kick the shit out of them so you will need to upgrade to solid additional parts for the rb26 solid would possibly mean thicker/ thinner shims to compensate for the different base circle thicknesses how do i know this? Cause i work at a machine shop and i actually have hands on experience not 2nd hand. But if you believe you do need to go Tomei lifters in a 26 don't let me stop you

You won't need new buckets, if its not broke don't fix it (I've used plenty of camtech/kelford tomei hks etc and ive never had any issue, i never replaced mine and i got the 10.8 lift) yeah base circles position/thickness does change but the shape doesn't, due to the position changing you will need to at least check clearances, (in the older days the shape would vary and the lifters were machined to suit each lobes shape) as mafia said, pick the cams based on their rev range i.e 2000rpm-6500rpm, this example means it will be a pig below 2000rpm plus best to chose parts to suit the cars purpose and rev range it will mostly use, i.e 11.5mm 290° rated 4500rpm plus is probably only best for drag racing not daily driving as it won't make power until 4500 (my n/a 26/30 run 10.8mm 252°/262° @ 0.050" and that is a pig to drive but then the cams start to work between 2200 and 8200rpm they were rated 3000+ on a rb26 bottom end)

You will need to machine the head it above the litter bores and yes you will need to get springs to suit (i got some if your interested, $180, they suit 10.5 lift not the 10.8 im running) You will also most likely need to reset the valve clearances