1995 vette, lt1 with top end intermittent knock???

Grumpy · Oct 25, 2015

sbodiford said:
Considering buying a 95 Corvette. Looked at it yesterday and it has a pretty hefty knock at what seems to be the very top of the engine. Knock is immediate at start up.. once car idles, it goes away... owner is asking 3k for it (does not know what is wrong with it). It has 120k on it... and some decent papers to show recent work, etc.. Just not sure if this is a lifter, bearings, rod, problem with oil flow, etc...
Worst case scenario, if it needs to rebuilt.... what kind of money am I looking at?

Have a video but don't see how I can attach...

New to the site... any feedback is greatly appreciated! Steve n Florida

Step back and think logically, if the only issues the engine may be trash,or it might be a minor issue and you need to determine which condition is true, and your willing and able to do the work to fix it its a damn bargain at that price, especially knowing that it may be something rather easy to repair like a damaged rocker or lifter or cam, the whole engine may not need replacing, and without inspection and detailed diagnoses your guessing at this point, it seems to me your thinking of buying an un-known quantity here but with a good many indications pointing to a darn good value or bargain, If the 1995 corvette looks good, inside (good interior and gauges work) and out,(body and paint ,glass look ok) and the car drives good (decent brakes tires, shocks , lights etc.)
and the only issue is an engine knock that,s intermittent , with the corvette, priced at $3K,
Id jump at the chance to purchase the car
, I dream about finding bargains like that!
as an engine rebuild is just not that difficult
and may not even be required
I can,t even remember all the engines I,ve rebuilt over 5 plus decades
(I lost count but easily exceeding 160 plus engines)
but its been a bunch and while a few were total scrap most were mostly reusable parts.
yes it might take you a weekend or two, the key here is the condition of the rest of the cars interior and exterior condition as engine rebuilds are just not that complicated or expensive or time intensive in most cases, but even minor but extensive body and interior work can get damn expensive fast, a combination of a few things like exterior paint ,worn seats,bad rugs, bad door panels, a cracked dash, or roof, defective gauges , could easily cost way more than the engine refresh.
for the one guy in every 10,000 that may not remember what a 1995 vette looks like heres two pictures I found on the net

Grumpy · Oct 25, 2015

http://www.superchevy.com/how-to/project-cars/sucp-0008-chevy-lt1-engine-build/

http://www.superchevy.com/how-to/en...no-testing-new-mods-for-the-lt1-motor-part-2/

http://www.summitracing.com/search/?keyword=lt1+rebuild+kit+engine

http://www.superchevy.com/how-to/4496-500-hp-na-chevrolet-lt1-engine/

http://www.airflowresearch.com/car-craft-nov-2014-pushrods.php

http://www.superchevy.com/how-to/engines-drivetrain/0612ch-lt1-engine-build/
[quote/f1fan]
Ok, here's what went into the 396 build

Block decked .017 to true up
Bored/honed with plates
size rods
Align hone
Clearanced for rods (~$120)

Compstar 3.875 forged crank
Callies p/n CAM113-CS
Compstar 5.850 forged rods
Callies p/n CSA5850DS2A2AH
SRP 4.030 forged pistons (-14cc relief)
(ACL bearings, total seal rings)
ARP main studs 134-5601

ARP head bolts 134-2101
Heads ported by Total Engine Airflow (52cc)
Milled .010 originally during first build up,
milled .020 on rebuild (plus typical "stage 3" type stuff)
Comp 1.6 magnum rockers
Comp 3/8 threaded magnum rocker studs
MLS .027 steel head gaskets
LT1 Intake, milled to match head milling and also port matched
GM intake gaskets
Arizona speed and marine 58mm throttle body
(I suggest not buying theirs if your car has ASR on it)

Canton 7" Road race oil pan 15-240T
Felpro blue pan gasket
Canton HV oil pump 21-560
Canton pickup 20-079

Comp magnum pushrods
Cloyes HD timing set
Comp cams magnum roller lifters
Comp cams 236/242 custom grind 112 LSA (actually an off the shelf cam from Thunder Racing)
Bosch 42lb Injectors on order
Spec stage 2 clutch (Was supposed to be sent neutral balanced, was 17g off!)
Spec aluminum flywheel
TPIS longtube headers
Random tech cats
X-pipe
Borla 2.75" catback
B&M Ripper shifter

Misc:
EGR removed
Moroso 8mm wires
Fueltronix fuel pump
Tuning
New Opti cap/rotor
Cut air lid
Descreened MAF

And probably some other stuff I forgot

No dyno yet since I was still waiting on injectors, hope to do that soon though

fwiw, my machinists advice on Eagle kits is that they are typically so far out of balance, that
by the time you pay for all the corrective machining, you could have bought better parts to start with
and less machinist time involved.[/quote]

I'VE ALSO FOUND SCAT KITS TO BE FAR BETTER BALANCED,
tolerances were kept closer and more consistently smooth & concentric barring surfaces

http://www.summitracing.com/search/...ily/chevy-small-block-gen-ii-lt-based-engines

HEADS
http://www.airflowresearch.com/popup_image.php?pID=96
rotating assembly
http://www.summitracing.com/parts/esp-b12107030/overview/make/chevrolet

1995 vette, lt1 with top end intermittent knock???

Grumpy

The Grumpy Grease Monkey mechanical engineer.

Grumpy

The Grumpy Grease Monkey mechanical engineer.