i,ve been watching this video and this guy makes it look that easy a few questions

1. the 2.5 block can the pistons and other stuff be be switched over to forged ones that are standard size.

2. or would it be possible to buy 2 block halves and just build a forged block with drop in pistons etc without any machine work.

all comments welcome thanks guys

http://www.youtube.com/watch?v=byfNt...E4037DCC330B7F

 

dont go for 2.5! there rubish cant hold much boost, go for 2.1 stroker kit with a closed or semi closed dech block! thats what ive done with my p1 but ive spent £5000 so that its a fast but reliable car and yes it did need machining, it was a 2.1 stroker kit from lateral performance, have a look on his websit

 

done that mate the 2.1 is fine but just interested in how easy this would be to do thanks

 

1.yes,if block is in perfect condition,but rings will need adjusting.
2. no not ever,block halves need to be matched,which means machining to gaurantee alignment.if you mean buying two already paired block halves,then it can be done if the bores are measured and no evidence of wear is found,however the head landings will need to be skimmed or lapped(machined) and then you need to be measured again for the correct head gaskets to maintain correct compression,if youre planning to do it your self you will need to be skilled(have some engineering knowledge)as you will have to measure and adjust the ring gaps to suit the bores and a whole load of other nonsense to bootin laymans terms get someone else to do it ,and get a gaurantee

 

for fast road then 2.5 is prob the best out there, the 2.1 can't get the torque the 2.5 can for low down grunt thast more important on the road.

 

A properly built 2.5 can handle high boost and all other things being equal will be a better road car than a 2.1: it spool characteristics for a given turbo will be better on a higher capacity engine and it will produce more torque.

My 2.5 sees 1.75 bar boost, at 3k rpm develops 480 ft lbs and 472 bhp- there are quite a few other 450/450 2.5 conversions over on the SC billet turbo thread if you care to look.

 

thanks guys is there a website that gives any info on a build

 

yeah - this one


Mick

 

2.5's are not rubbish.

 

hi, new to subaru tuning, in your opinion which aspect of the 2.5 "cant hold much boost" as as far as i can see they are the exact same engines with only a bigger bore size, prehaps the liners fail? From my experieence with tuning other engines, i would always say a bigger capacity engine making the same power as a smaller capacity engine is always a better drive.

 

I think he means the block is not strong enough. At a certain power level yes it does become un-safe however the block can be modified to take more boost such as pegging etc.

 

I see, for the majority of people with realistic power levels, upto 300 bhp, i cant see it being a major problem though? i know i would prefer the 2.5 making 300 bhp than the 2 litre making 300 bhp, more torque, less boost, less lag, better drivability. And im not bein biased, as i run a 2 litre.

 

ok guys whats needed bearings pistons etc. any help to draw up a list would be appreciated of what would be best to use power 500/500 or close to it.

1. 2.5 block halves

 

[quote=playtime;9960045]ok guys whats needed bearings pistons etc. any help to draw up a list would be appreciated of what would be best to use power 500/500 or close to it.

1. 2.5 block halves
2. forged rods and pistons
3. race bearings
4. steel head gaskets
5. 11mm heads studs
6. 79mm crank
7. manifold, turbo, injectors, fmic, frp, fuel pump

Plenty more stuff to add....

 

[quote=banny sti;9960053]any apecific names of parts i would use banny
ie. which brands

 

and costs

 

a few other questions

1. what pistons and rods
2.what size of headgaskets
3.what bearings do i buy do they come in a set for the block
4. is the standard size of the bore on the 2.5 engine 92.5mm are there any drop in pistons available.

chaffe if i get the names of the best parts to use then i will shop around for the best deals i,am not wanting to cut corners cost won,t matter as i,am takeing my time with this and buying what i can afford at the time cheers.

 

1. 2.5 block halves
2. forged rods and pistons rods - arrow, carrillo, pauter or crower and pistons wiseco, cp, mahle or JE piston size is 99mm
3. race bearings ACL race bearings
4. steel head gaskets from lateral performance who will advise of correct size
5. 11mm heads studs arp or cosworth
6. 79mm crank from subaru or lateral
7. manifold, turbo, injectors, fmic, frp, fuel pump

manifold gt spec turbo MD321T injectors 740cc hybrid fmic fuel lab fpr walbro high pressure pump

 

thanks banny i,ll do some digging with regards to the pistons.

 

is anyone running a forged 2.5 block what are you using parts wise