rebuilding buick 3800, what sort of things should i consider???

[Gav86]

looking at rebuilding my vn v6 as i wanna throw some boost into her, what sort of things should i be replacing and with what so ive got a strongish motor, dont wanna spend too much

[Morton]

Well that kinda depends on how much boost you want to cram in there How many kays do you have on the engine + how many PSI do you want to push?

But to give you an idea, people have generally run up to 10psi safely without opening up a buick 6 - given that the engine has around 200,000km on it, and runs nicely.

[Gav86]

yeah but i see those ppl killing there motors in 3 months too, what is it that dies on them? pistons slamming into bores?? rods?

[stocky]

mines been running boost for a year now. still going fine

[cruzncommo]

buick grand national conrods/pistons, custom grind cam, work too block, stroke to 4.2L, lots of headwork, better valve setup, bigger tp and port matched manifold, double row timing chain, aftermarket computer.

[PaRaDoX]

bah,

ok ill tell you...

what kills motors with boost
-----------------------------
pre-ignition
detonation
pinging..

geuss what... its the same thing... the BIGGEST killer of motors with boost is detonation, most people dont change injectors or tune, leading to MASSIVE detonation blowing out headgaskets, shagging bearings etc..

you can run upto 14psi on a stocker 200,000km+ buick motor SOLONG as its running within 10-12 afr on boost,

what happens with detonation is the bearings get slapped round and end up spinning
when i turbocharged my ol v6 i had a issue, the timing was broken due to the balancer being off key.. this meant i had +10 deg spark all the time (same as a dissy cap) this destroyed the motor see pictures...

the damage:
cracked heads
crap on pistons like melted on
2 spun big end bearings, 1 spun main bearing. all bearings shagged
timing chain tensioner snapped.. probbly lots more damage i just didnt find it





what i can reccomend is, get a good running motor, and boost that,

solong as you dont go over 14psi you shouldnt throw a rod or brake any pistons
personally id run 12psi max

i blew a headgasket then ran ACL race series ($120 a pair) the motor broke before these.. heh

weak points of the motor:
------------------
bearings
seals letting go
pistons & rods only rated to 14psi
valve springs are spongy and will limit power over 3000-3500rpm
valve stem seals are usually gone
inlet gaskets usually leaking water into engine

strong points
-----------------
crank can take alot of punishing
heads are strong
faily easy to tune

please listen to my advice, ive spent a year of playing, braking, learning and experimenting, not just some newbie jumping on here saying do this this this.. i got vp lukes engine which went thru a year of being supercharged, then turbo charged, and when i got it, it ran perfect up untill the day my mum wrote the car off :P
that motor was bog stock except stronger valve springs

soo yeah strong motors solong as they're tuned!

[Gav86]

thanks man thats exactly what i wanted to know.

[PaRaDoX]

glad my shagged engine could help someone out

your most likely to shag a bearing than throw a rod, remember to always check boost levels via a gauge soo you dont over boost.. also oil pressure is essential, id reccomend getting a gauge

[Full Spectrum]

You could also look up the Formula holden engines they were some big reeving motors.

[LowVp]

but they are built for N/A and run a higher comp ratio and not suited to boost

[Full Spectrum]

Go without boost be the only Buick running over 8000rpm.

Take more on the bottom end but you should be able to pinch some ideas from it at least.

[LowVp]

N/A hp has more wear and tear then a engine under boost just due to the revs

[Full Spectrum]

I'll take boost.

[scrabet]

bah,

ok ill tell you...

what kills motors with boost
-----------------------------
pre-ignition
detonation
pinging..

geuss what... its the same thing... the BIGGEST killer of motors with boost is detonation, most people dont change injectors or tune, leading to MASSIVE detonation blowing out headgaskets, shagging bearings etc..

you can run upto 14psi on a stocker 200,000km+ buick motor SOLONG as its running within 10-12 afr on boost,

what happens with detonation is the bearings get slapped round and end up spinning
when i turbocharged my ol v6 i had a issue, the timing was broken due to the balancer being off key.. this meant i had +10 deg spark all the time (same as a dissy cap) this destroyed the motor see pictures...

the damage:
cracked heads
crap on pistons like melted on
2 spun big end bearings, 1 spun main bearing. all bearings shagged
timing chain tensioner snapped.. probbly lots more damage i just didnt find it





what i can reccomend is, get a good running motor, and boost that,

solong as you dont go over 14psi you shouldnt throw a rod or brake any pistons
personally id run 12psi max

i blew a headgasket then ran ACL race series ($120 a pair) the motor broke before these.. heh

weak points of the motor:
------------------
bearings
seals letting go
pistons & rods only rated to 14psi
valve springs are spongy and will limit power over 3000-3500rpm
valve stem seals are usually gone
inlet gaskets usually leaking water into engine

strong points
-----------------
crank can take alot of punishing
heads are strong
faily easy to tune

please listen to my advice, ive spent a year of playing, braking, learning and experimenting, not just some newbie jumping on here saying do this this this.. i got vp lukes engine which went thru a year of being supercharged, then turbo charged, and when i got it, it ran perfect up untill the day my mum wrote the car off :P
that motor was bog stock except stronger valve springs

soo yeah strong motors solong as they're tuned!

those crank bearings look like mine sorta sep mine wasnt under boost just previous owner stuft it buy doing head gasket and water and oil mixing and driving it like that

[vn calais manual]

are all v6 pistons interchangable up to the aloytech?

eg vn,vp,vs?

[tappet]

smaller 2/3 and 5th cyl oil ports are much smaller in the block than the rest, chappy in the states drilles em out to 5/16 or even 3/8 with no pressure drop as i have done during rebuild, google Jack Merkel in the states, has some rather warm mod options there!!!

[tappet]

i have stock rods and slugs from a vp in my baby/warm VR, as block was std too

[tappet]

also timing cover will let oil water mix if corroded too much and doesnt do the oil pump any favours either

[ClairBear]

Tappet: I would love to tap you on the head hard for digging up an old thread.