lets pretend.

[lucky7]

lets say my RB25 has low compression. lets say a couple of rings are bad. what is the best route/cost effective route. i want a maximum of 475whp out of this car. do i source a new swap/engine from a sponsor on here and part out my existing motor? or do i pull it apart and go with forged pistons and GTR rods? keep in mind, i would not be doing either the swap, nor the rebuild.

another thing to consider. my turbo is being a bastard, and it wants to be replaced with a GT3076R. buying another engine will give me another good turbo, therefore saving some money upfront, and using the stock one while i save for a big turbo.

anyhow, what sort of costs go along with a basic build? new gaskets, rings, bearings, etc. im just trying to figure out what my best option is. i havnt even checked the compression yet, but im assuming thats what the smoking is from. and why it sometimes stumbles when starting.

anyhow, thanks alot.

[240wootie]

i would do some research and find out what all the parts would cost you to buy (pistons, rings, rods etc) and weigh them against the cost of a new engine. if it were me and the money was the same for a rebuild or new engine i would rebuild. it would give you a better platform to work off for more future power, instead of getting another stock engine. you arent going to make up for the cost of a new engine by parting the old one out. keep the stock turbo and save for the bigger gt3076r. just my $.02

[lucky7]

lets see here.

-CP forged piston kit, 8.5:1 compression ratio with standard 86mm factory bore or 86.5mm bore (0.02" over). Sale price: $849.95

-Nissan con-rod bearings for RB25/26DET. Priced per set of 2 bearings Sale price: $11.95.

-Greddy 1.0mm metal headgasket for all RB25DET. Sale price: $276.25.

-ARP high strength head stud kit for RB20DE(T) and RB25DE(T). Sale price: $145.00.

-Factory Nissan exhaust manifold gasket for RB20/25DE[T]. Sale price: $39.95

-Complete R33 RB25DE/DET or R32/33 RB26DETT full rebuild gasket kit. Sale price: $199.95.

-RB26DETT connecting rods (oem). price = ???.

-piston rings. price = ???.

-rod bearings. price = ???

-machining??

took the above numbers from phase2. im sure i could shop around some more. but im thinking that a built bottom end will save for less headache in the future.

[madcowvert]

if you do all that you should think about fixing the crank collar.

you'll need new rod bolts, main bolts and all the machining for all of it.

But i agree if you had to pick between rebuilding and buying a new one i would rebuild. Heck before i put my motor in i was thinking about building the bottom end.

[lucky7]

i forgot about the crank collar. ill have to start making a list of everything. this would be effing expensive, per usual. damn RB's. i should have bought a mustang.

[wawazat8402]

new forged pistons come with the rings.

[lucky7]

ive heard that in some cases, chrome oem rings are stronger than the aftermarket?? i have no experience with engine builds. but good looking out. my buddy works for a custom piston company here in detroit. they do everything. i just remember this, so i sent him an email. he just did pistons for a john deere lawn tractor recently. lol.

[s13rb28]

probly would be a good idea to have the crank checked/balanced, to make sure it's still good. be a shame to rebuild and have everthing you just did get ****ed up

[NightKids2]

RB25? Bad turbo? Bad compression?

... Are you ME?!

=)

I'm in about the same boat and I've gone over the same thoughts. I think what I'm going to do is rebuild, cause I figure buying a whole 'nother clip would be a waste of money and if I got engine only I could never get rid of my old one with no transmission or harness, plus it seems like a waste of money to buy another motor when I already have one, so I'm gunna go from there.

[Darius]

If you don't want to mess with with rebuilding it, you can always sell your current motor and get a newer one that has good rings in it. You could slap a 3076 on there without worrying about internal condition. Once you blow it up, THEN rebuild it.

[lucky7]

decisions, decisions. good thing is nearly october, and the car is gonna sit for the next 6-7 months anyways. ive got plenty of time to figure this **** out. its kind of annoying though. i really should have just gotten a 97 cobra and put a kenne bell on it. lol.

[lucky7]

hey darious. i know you build your engine/ do you have a place with an actual spec/mod list? if perhaps you do, you could post it here, or email me. that'd be cool. [email protected].

[eh?]

machining??

Figure about $1500-2000 since you aren't doing anything. I spent $900 on machine work back in '03 and I blueprinted and assembled everything except the valve train myself.

I got a new long block from venus for $500 back in '05 . I'd rather buy new long block and get a perfect before I'd ever consider building an engine for only 475rwhp.

However since you already have/had a properly running engine you should consider going for more whp and do the build.

[lucky7]

well, say i tossed in some CP pistons, and GTR rods. using pretty much everything else OEM, i'd assume that would be good for 600hp. would i be right thinking that GTR rods are safely maxed out around 600? keep in mind, i dont plan on touching the head. i just dont have the money for it right now. hell, i dont have spare cash to build the bottem end right this second. so this would be done over the next 7 months.

[eh?]

If you don't have atleast $4k I wouldn't consider a rebuild. Little things start adding up quickly. Consider a new long block and keep the old one while slowly buying up parts for a rebuild.

[lucky7]

i like that idea, but i dont want to re-buy a water pump and fuel pump. like i said, the car is going into hibernation for the next 7 months. in 2, i'll have 4k to throw at it. so im not pressed for time or anything.

but again. GTR rods? or should i just go aftermarket there also?

[eh?]

Polished RB25's with arp bolts.

[rb25drag]

Basic build your not going to find a std bore piston. The smallest is .020 over.Go with Weisco forged pistons they come with chromoly rings and forged rist pins for under 600$ for the set of 6.Acl race bearings is the best. little over 100$ for the set of main and rod.ARP head studs is a must. 150+get a 3 layer steel headgasket. 200+If you plan on making only 400+ HP I would recommend using the stock rods. Machine work is going to consist of block bored, possibly decked according to how straight the deck is. Limit is .002 to remove.I would also recommend getting the motor balanced. It helps a ton and helps to improve engine drag. Aslo puts less stress on your bearings.You can buy a gasket set for a little over 100 for the entire re-build which is going to give you new valve seals for the head. You can have a 3-angle valve job done. But as long as the re-seat the valves back in. They will be as good as new. Make sure you get the head re-surfaced too!!!! Over all you can do a mild rebuild to handle 400HP including machine work for around 3 grand.

[Fearsome_tea]

You dont need forge pistons for that much power. If you need I proly got some laying around. You pay for shipping there yours.

[lucky7]

im pretty sure the pistons are my issue. and while its apart, why not.

but i would be shooting for more than 400 if i went trhough with the build. probably more like 500+.

but thanks for the replies, guys. i appreciate it.

[bumblebtuna]

Basic build your not going to find a std bore piston. The smallest is .020 over.Go with Weisco forged pistons they come with chromoly rings and forged rist pins for under 600$ for the set of 6.

they don't sell standard bore/compression ratio over the shelf, but if you feel like waiting a month they'll make you a custom piston.

what i did/am doing is sending mine to JGY Customs. They send them (the specs really) to CP Headquarters in Cali, then CP drop ships them to your door. If you have the time and wanna save some money (assuming your cylinder walls aren't fubared) i'd recommend it for a few reasons. For starters, your car won't feel like a turd out of boost (like lower compression pistons), you can make more power off less boost, better gas mileage and save money from the machine shop, assuming you assemble it in your garage.

sending mine off tomorrow actually.. good luck man

[Darius]

You can get CP pistons at stock bore (86 mm), but the CR is 8.5:1 or so. And GTR rods are about 50% wider than the RB25 rods. Cheap insurance if you ask me. You will never hear of a rod breaking in an RB motor unless the thing was untuned or poorly tuned. It is always the rings or ring lands that blow first.

[eh?]

My Ross racing pistons were 20 over and around 9:1 (don't remember the dome specs, box is gone).Back in '03 they were the only company with the correct rb25 specs in hand. Dunno if anything has changed.