Finishing Up Forged Cp Piston Rb30 Build, Few Q's

[Swiper the Fox]

Ive tightened up the old Cp's a quarter of a thou...no issues at all. But the newer ring package they come with seals a lot better and really there is no need to run 3.25 thou. 3.5 thou will allow you to run as much boost as you like as well.

beware though...some guys use mild steel torque plates but they do not flex like an alloy head does and doesn't replicate whats really going on when a head is fitted to the block.

[jarrod83]

the final honing got done today :S without a torque plate.. gave up arguing with them as they recon it wouldnt make f**k all difference.. picked the pistons up from the ceramic shop so they could be measured... somehow they were all exactly 1thou bigger than the factory specifications so they honing it out an extra thou.. i had the pistons double checked by an engineering place and they arrived at the same results... when the pistons get back from the ceramic shop if they are noticeably bigger or uneven ill take everything to another shop to get torque plate honed.. but the ceramic shop said the extra clearance from the coat on the skirts doesnt effect the clearance as its a dry film lubrication layer and the skirts run colder with the crowns ceramic coated.. ill double check again tomorrow with them when i drop the pistons back off..

good to hear the newer rings seal better..

Thanks for the info guys, hopefully it all comes together even if it costs a little more

Jarrod

[Rolls]

how did it all go in the end ?

[paulR32gtr]

Very very interesting read thanks for digging this one up Rolls. Interested to hear how it went.

[r33_racer]

The testing weve done has shown bores can be out of round by upto a thou + if not done with a proper torque plate. If a machine shop says it doesnt make a difference, take it to someone else. Also make sure you use the same headgasket and bolts/studs you are using in the build when the machining is done. This is important.

Abit late in this case...but for future reference.

Edited October 25, 2010 by r33_racer

[jarrod83]

no worries r33 racer, i was about to send my block off without my ARP main and head studs, maybe i should add them in. Overall the build up went pretty well first time around, when i first started the rebuild i had like 3k and was planning just a standard rebuild, bore ended up being rusted and stretched the budget as much as i could to include forged internals, arp steds, ceramic coating etc.. probably should of payed a little extra and gone to a better machine shop and a new oil pump.

The ring gaps ended up being huge.. they were considerably larger than the 21thou i had calculated, i was 2 weeks past the end of my holidays and decided to through it together anyway, decided to run the internal vct feed and left the oil restrictors unrestricted, had tonnes of oil going to the head and had the vct doing some weird clicking.. so going to go to an external vct, run oil restrictors and replace the solonoid this time.

Engine was running sweet for a while, had a few teething problems on the dyno and never made over 450rwhp due to it leaning out with a melted alternator bolt first time around, went to a different place second time and melted all the wires around the dump pipe.. boy do they get alot hotter once everything is ceramic coated but the dump pipe, plus it doesnt help that my wastegate runs between the dump pipe and the body of the car.

Ended up discovering that the timing belt was out half a tooth, so considering that my 450rwhp effort wasnt half bad considering it stopped early and look like it would of easily made 470+ on 21psi with low timing. the goal was 500rwhp, should make it.

had a few problems with the harmonic balancer and the keyway, whether the bolt wasnt done up enough or the keyway was flogged out, it ended up getting weird pitting all on the inside of the balancer, had to replace it along with a new keyway.

A few burnouts later i was going up a hill one night, clutched second and bounced to the limiter and got a strange knock reading, after that, whenever it hit high boost it would knock and occasional when you were driving around town at low speed it felt like was hitting a brick wall for a split second.. swapped the ecu and afm for a haltech ecu n map sensor and it seemed to fix the problem, sent the car to get re-dyno'd and the oil pump shat itself.

Pretty sure i broke the pump on the limiter and it was bouncing around still working for abit before it completely let go, possibly caused by the problems i had with the harmonic balancer.. though im sure the limiter bashing in the burnouts didnt help

whilst i was pulling the engine apart to replace the bearings and pump.. i found ceramic spark plug insulators in the exhaust, most sickening feeling.. anxiously pulled the head off only to discover the spark plugs had all came apart and trashed the engine. The spark plugs are a bit of a long story, in short i changed my usual plugs from bcpr7es to the equivalent v-notched ones, picked them up a day later to find out they were 5s and that the 5s were infact a colder plug than the 7s, took the car to the tuner with the 5s in and questioned, inwhich he agreed that the 5s were no good so we went back to my original 7s, i said they were a little bit fouled up and that i would give them a quick clean and pop them in, in which he claimed he could just give them a quick clean up by quickly burning the oil of with a oxy, bringing them up as good as new.

So rebuilding, hoping to get all the little things right this time, starting with a new block/crank, sending it away to get machined this time, getting a proper oil pump, harmonic balancer, oil cooler, cams, springs etc.. hoping to crack the 400rwkw mark with some help from the water methanol injection.

hoping this time to spend alot more time doing away with lines and wires i dont need and simplifying the engine bay as much as possible and fixing all the little things that i wasnt happy with last time

Spewing i have to wait so long to have a play with my new haltech ecu and WMI

[Rolls]

stories like that always make me sad, so much time and effort only to have it asplode. =(