Forged Rebuild

[Motoquipewa33]

Hi guys, i know it might be done to death, but i am looking into doing a forged internal kit in my 25 to support my 35r and supporting mods upgrades - wanting 500+ hp

Im going to presume a balance is a must???

And if so, who has had this done and by whom and what was it like $$$ wise

Thanks guys

Shelby

Edited August 21, 2012 by Motoquipewa33

[kitto]

Just had my RB25 NEO done by my engine builder.

Hot Wash Block

Balance crank, clutch

Weight match pistons and rods

Bore and hone

Deck block

Grub Screws

Grub Screw crank

Fit crank Collar

Linish Crank

Check all clearances

Assemble short engine

All that came to $1320 No Parts Included. All my head work was almost double that.

Balancing your rotating assembly is a good idea!

Not sure about who you'd go through in Perth

[Greekos]

about 10k + or - to get a solid engine built with a few changes in the head done, it will need to be balanced by someone who know's what they are doing, and it can take up to a year to get done right, then there is the whole cooling aspect as well, it all adds up, but do it once and do it right and in the end you'll save money and headaches, finding a trust worthy workshop is also hard these day.

[Motoquipewa33]

yea that is hard these days.. one place has quoted me $3500 just to balance the engine.. im not sure if that included fitting the parts which I will be supplying, and fitting personally.

ive also heard that the stock rb25det bottom end is good for 450+ hp... not sure if im willing to take that chance, im not having any issues with det, or smoke or compresion.. not to sure if i should see how i go on a safe tune for a lil bit till i do some more research....

[R31Nismoid]

Have you tried the seach? There is more than enough info on here to cover your everlasting questions.

Have a read, and get some knowledge going

The stock bottom end is ok for NO MORE than 450hp (motor, no wheels). Any more, for extended periods, doesn't seem to last.

Either way, it's a 7-10k expedition depending on how much you want to spend.

[AngryRB]

Do all engines with forged pistons have piston slap on cold starts??? seems self defeating if you spend all that money and have piston slap on start ups , the piston rocking in the bore all the time would surely make the whole expense of it a bit self defeating, would have accelerated wear on every start up wouldnt it?

[Moodles2]

I think noise with any piston whether cast or forged is the silicon content, low silicon content will tend to expand more when getting warm vs higher silicon content.

[R31Nismoid]

Do all engines with forged pistons have piston slap on cold starts??? seems self defeating if you spend all that money and have piston slap on start ups , the piston rocking in the bore all the time would surely make the whole expense of it a bit self defeating, would have accelerated wear on every start up wouldnt it?

Only ones that are put together loose to begin with. None of my motors have ever made noise on start up.

I've heard plenty of other builds over the years and most of them also do not have noise either... But there is always one every now and again that rattles it's nuts off... I certainly wouldn't be happy if that was mine

[zebra]

Any (street) engine built these days with forged slugs should not have piston slap

full blown race engines built loose (ala NASCAR/Super taxi's?Pro Stock Drag cars etc) will have some when cold, but 99% of the time they have engine pre-heaters to avoid the start up wear

[OMGGTR]

my 400kw setup has cost me 20 grand and the engine is still on a stand... also i have done all the labour except for the head work machine and balancing head costed $2000 balance/ machine was like 1500 including all new welshplugs etc... prepair to fork out alot of money