Help, suggestions and opinions welcomed - rebuild time!

[Anonymous]

Myself and a friend are about to tackle a budget rebuild/refresh of my GTI-R engine. Before anyone slates me for attempting a BUDGET rebuild, telling me if i can't afford a proper rebuild then i probably shouldn't be running a GTI-R, let me just say that i have a good few things i want/need to do to the car so the overall investment won't exactly be small. Plus, by doing it myself with some help, I'll manage to get a much better understanding of the internals of my engine.

The main things being replaced will be the pistons (going for 87mm forged ones) along will all the bearings, gaskets, oil & water pumps, hoses and con-rod bolts. The aim is to run it at about 1.2 bar and we're hoping to get somewhere in the region of 300-330bhp from it.

Since this is being done to a budget I'm looking for opinions on a few different ideas i was thinking of doing while the engine is apart. Some of you may have done these things (in which case opinions would be invaluable) while any other opinions would also be welcomed.

Head properly ported and polished? Is it worth doing this considering the standard cams will be staying in the spec for the near future (may upgrade once the bank account recovers)? What sort of gains could i expect from it? Expense?

Polishing the inside of the inlet manifold, throtle bodies, exhaust manifold and turbo elbow? I've seen a few threads where people have done this while their engines have been apart, and while they certainly look good all clean and smooth, is there any gains to be had from this? What parts in particular would benefit from having the casting marks removed? This would be one of the more budget tasks which would only really require my own time and effort to achieve.

Crank, flywheel and con-rods lightened and balanced? Is it worth doing any or all of these? Expense? Or should i just put it back together with new bearings and uprated con-rod bolts?

Any suggestions as to where i could source parts from? Are Nissan the only place for the gasket sets, pumps and bearings?

Along with the internal stuff I'm also planning on modifying the intercooler to mount it on the front, oil catch can, cold air feed, fitting an upgraded clutch (suggestions?), bigger front breaks, some suspension work and then i have the wonderful dilemna of figuring out what to use to control it all (at the moment i'm thinking of a unichip/profec b-spec combination set up on a rolling road). Anything else i should consider?

Thanks for any opinions! 8)

 

[Keira]

unless its already broken i wouldn't do any of the above engine wise, the standard engine will run 330bhp all day long with the right bits on it.

i'd do the other bits you want to do first and get the car tidy.

its just my opinion but its a waste of money to rebuild the gtir sr20det and run it at power levels that the standard engine will easily produce.

for parts mike at mjp is good, genuine nissan parts to 01277374201

 

[pete-r]

Go for 400+ ,my standard internals were taking 350 all day long with no problems.If its not broke ,dont fix it.

 

[Anonymous]

Thats just it guys - it is broke. One piston has a lovely hole in it so it has to come apart and they have to be replaced.

The reason my aim is for 300-330bhp is that it'll be in everyday use, and also running the standard turbo.

 

[GINGA]

A basic rebuild would be fine with just the forged pistons, steel head gasket and arp rod bolts for alittle extra safety.
Its pointless get the head ported and cams etc for 330hp and you'd just be wasting your money, just have the head overhauled with new guides and valves relapped etc for a decent job 8)

 

[GTI-R Kid]

Its no wonder people are getting disheartened with this club. 93 views and only 4 replies when someone asks for some help and opinions.

I've polished the inside of my plenum and inlet manifold. I don't know if it will yield any performance improvements but i was bored and had a spare so i got to work on it.

If you're thinking of doing some porting and polishing have a look at the link below. They have diy guides for porting and block preparation. Makes for interesting reading anyway and has me thinking about what other improvements i can make to our engine.

http://www.sa-motorsports.com/diyguide.shtm

 

[Stevo]

if i was u id do the follow

Forge pistons
standard crank and rods
arp conrod bolts
arp head bolts
thicker head gasket
boost control
uni chip or another aftermarket
front mount intercooler
oil cooler
uprated clutch like ap helix
then u can run 1.2 bar on standard injectors all day long and hope to get 330 bhp.
You can install a HKS 264 cam so u run less boost but get power gains.

So far i have a standard engine and intercooler and get 308 @ 1.0 bar

im going for front mount oil cooler arp bolts new gasket and running 1.2-1.3 bar and hoping for 340 bhp

 

[paz]

Its no wonder people are getting disheartened with this club. 93 views and only 4 replies when someone asks for some help and opinions.

I've polished the inside of my plenum and inlet manifold. I don't know if it will yield any performance improvements but i was bored and had a spare so i got to work on it.

If you're thinking of doing some porting and polishing have a look at the link below. They have diy guides for porting and block preparation. Makes for interesting reading anyway and has me thinking about what other improvements i can make to our engine.

http://www.sa-motorsports.com/diyguide.shtm

I could give you an answer, but won't, as I don't have enough knowledge to do so - not everyone has a great enough level of mechanical knowledge to answer your question

Paz

 

[GTI-R Kid]

Paz - i get your point about the fact that not everyone has the expierence and knowledge to answer, and while not wanting to start a debate on it i will make a few simple points that should illustrate why the initial response was disappointing.

1. How many people on the forums have had an engine rebuild and would have recieved advice from their builder before deciding on a plan of action?

2. How many people have attempted different porting and polishing ideas to try get a little better power or air flow through their motor (a search reveals at least three threads where people have polished their plenums and intake manifolds)?

3. How many others have done research into engine rebuilds even though they may not yet need it or are not in a financial position to do it yet?

My point was that the original post was simply asking for advice, opinions and suggestions. There are definitely more than 10 people on this forum who have such expierence and knowledge that they could offer such opinions.

Sorry for going on and kinda hijacking the thread, i just feel a little disappointed (like many others it would seem).

8)

 

[paz]

Don't get me wrong, I do agree I just also feel its not fair to tar everyone with the same brush :lol:

Good luck with the rebuild Mr Guest, hope it works out for you

Paz

 

[Norfy]

i am also planning to do a DIY engine upgrade/rebuild, am still getting info and would luv to help, but i dont wanna give out any info that isnt 100%.

i have a spare engine and am planning to build it up to a spec that could take about 400bhp (even though i wont be anywhere near that figure for a while).

follows is a spec list of what im after, hope this may help you guest.

standard crank being knife edged,
arp rod bolts
87mm forged pistons
not sure on rods yet, would ideally like uprated
steel head gasket
arp head bolts
polished and ported head seeing as the head gasket is a bit pricey
other than that, im looking at the internals of each part and thinking about smoothing the casting marks off to possibly help oil flow.
other mods can be added later without removing the engine.

Norfy.

 

[kirko]

there is no need for new rods, crank mods or porting of the cylinder head as these can easily produce /take 400+
forged pistons, arp rod bolts and a good honest rebuild is all you need
dont take it to a tuner :? take it to your local engine reconditioner (who rebuilds engines all day every day) then you have the grounds for a reliable and fairly budget rebuilt engine :lol:
when it comes to fuelling though you have to get it mapped :!:
this is the biggest cause of engine failure after boost hikes
porting the exhaust manifold and turbo elbow are good mods to help it breath and will help the turbo spool up :lol:
with these mods if the standard turbo was in as new condition it would easily give you 330-350 bhp at increased boost levels

just my thoughts on the subject (dons fireproof suit)


dorks :lol: