400whp on stock bottom end.

[Nicksemianiw]

Ok rephrasing the question.

I'm building my head and getting alot of new parts in the next 2 weeks the car will roughly be putting out 400-420 whp. I dont need to build my bottom end, but should i do it anyways because the head will be off. And is it really worth the time and money at this point. I dont plan to go over 450 whp with my car so i dont think it will be bennafical. What is your guys take on this?
Modified by Nicksemianiw at 2:53 PM 4/23/2005

[Blown240sx]

well 420 WHP is about what 500 at the fly? Id say if your going to that HP the bottom needs to be built also. Ive heard the stock bottom end only holds 350-400 at the engine.

[Nicksemianiw]

They can hold 600 whp on stock bottom end, all i am basicaly asking is it worth doing. I know i dont have to do it and it will be ok, but while my head is off is it worht doing the bottom end at the same time even though i dont need it. I probaly should have phrased it better.

[180fan]

It'll cost alot to do the bottom end right. Just because some motors held 600 doesn't mean yours will. Depends on the condition of your individual motor. While it's off though, you might want to consider new bearings and rings to freshen up the bottom end.

[Nicksemianiw]

If i replace the rings i might aswell do some CP pistions or somthing because even with the new rings i will still have to break it in. Building the bottom end wont cost more then 4K and thats fine. But i am just wondering if it is even worth it or if it is pointless

[llamabeta]

If your in there might as well especially if cost isnt a concern of yours. If you ever want to increase power youll know you have a tough block in there.

Throw in some custom made titanium connecting rods, yo!

[cheez80]

for "my" track car, i am not having the bottom end built. specs currently are

gt-rs turbineescort racing spl intake manifoldwasabi garage top mount exhaust manifoldhks gtii wastegateport polish, port match, valve job, etc., etchks 272/272 step 2

etc., etc. the car should hit about 400whp on c16. i think (my tuner shares this philosophy) that a car pushing 400whp doesn't need bottom end work.

[TruboostPerformance]

Your fine with 400hp on stock bottom end

[mynismo]

you wont need the bottom end. i drive the piss out of my car daily at 18psi and its putting out near that...

you probably should be considering built internals around 450whp mark.

[kouki180sx]

I am leaving my stock bottom end and just adding a head gasket and studs when I build the head. I should be pushing about the same power. I think it is safe. Each engine has been abused differently though

[ItzGenX]

Building the bottom end will just give you that piece of mind also. It can also be there one day if you decide to put more power to it. Stock bottom end has been proven to hold up into the 600's, but some haven't come close. It is almost a hit and miss deal due to CAST aluminum pistons. Some may be casted better then others. Just look at all the broken ring lands and sheered pistons on not only this forum but all the others too. Also, reaching high hp on stock pistons involves very fine tuning. The slightest slip will lead to a piston and rod vaporizing everything. Some were not as lucky as others when coming down to piston failure and ended up with a hole in the block (the whole piston let go, letting the rod beat everything up). Forged pistons and rods also lightens some rotating mass, helping with throttle response. It is a matter of user preference. If you want to do it, go on and do it. If not, just be careful.

[Beemen550]

If i replace the rings i might aswell do some CP pistions or somthing because even with the new rings i will still have to break it in. Building the bottom end wont cost more then 4K and thats fine. But i am just wondering if it is even worth it or if it is pointless

for 4k i could build the whole motor

pistons $500 max rods $300-500 rings,bearings,etc $200-400 polish crank $100 max arp bolts $200+

and this is just a rough estimate, ive seen piston and rod kits for $600-900 on ebay all day, nissan bearings are very well priced, unless u want some clevites or somethin, but really search around u can get all the stuff for the bottom end for under $2000 or i know i could

[180fan]

Do not forget machine shop costs. With ARP bolts, your runout values can and probably will change. Do not expect them to be the same as with the OEM bolts. ARP main bolts changed the line bore, the rod bolts changed the runout on the rods for me. With the head studs, I've yet to measure that with the studs in. Don't think it's just a slap it in affair as it could very well NOT be.

[240Kuminachu]

Yes you should build the bottom end if your wanting that much power.

It will last longer.If your going to do it, do it right. Enjuku put out like 560 at the wheels on a stock bottom end, doesnt mean yours will, how long will it last?Piece of mind.Ceramic coat them while your at it, it will help disapate heat, turbo motors make heat, heat will kill your motor.I recomend aries pistons, they come with rings. Go .40, to 87mm, helps out torque. Think about it, your more than doubleing the stock power of a 4-banger, its not made for it.

My buddy just blew his SR, he was 450 at the crank, forged bottom end. Due to octane, he melted the pistons, 425 seems to be about the limit on 92 octane.

I dont want to see you waste money on a motor that is pushed to close to its limits. Its better for the long run. YOu've been in this for a while, longer than alot of guys on here, you should know building the bottom end should not even cross your mind twice at that HP level.

Your better off, just do it.

[Nicksemianiw]

I know the bennifits of building my bottom end, but all i am asking here is if people think it is worth it when i dont really need to do it. Basicaly the question is build the bottom end now so i dont have to do it later on. And at 400-420 WHP a stock bottom end on a sr20det is FINE it will handel it perfectly fine with GREAT tuning of cource.

Nick

[Onizuka]

Its up to how much risk YOU are willing to take. Asking us wether or not you should take a gamble on your motor just doesn't make sense. Sure the motor might be able to hold the power. But it also might vaporize your bottem end, destroying the entire block. Its up to you.