Build a 308

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Page created by MRHZV Feb 10th 2005:

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308 bore, note: scoring in bore,this will not hone out! Click to Enlargen.

How to Build a Nice 308 for the Street:

The first order of business when building a new motor is to find a suitable donor engine for the build, If you have got a 308, good! if not get your wallet out cos they are not getting any cheaper. Also as a general guide, be prepared to spend more than what you planned to as the cost can add up very quickly, and there is no point in leaving out new oil pumps,new valves springs etc etc to save a few dollars because if you do, you are asking for premature engine failure which in turn costs money.When looking for a suitable engine, bore size and condition is important, if in doubt take someone with you that knows if,how,where,what and when and finally shop around!!!!

Pistons and Rings.Click to Enlargen.
LT1 valve springs. Click to Enlargen.
New arp rod bolts
crow timing kit. Click to Enlargen.
crow cam. Click to Enlargen.
Me fitting kings main bearings to con-rods; note: slotted bearings to increase lubrication. Click to Enlargen.
Heads before servicing.Click to Enlargen.

Heads after servicing. Click to Enlargen.
308 crankshaft sitting in block. Click to Enlargen.
bottom end assembled. Click to Enlargen.
308 engine bay. Click to Enlargen.
Engine fully assembled. Click to Enlargen.

Please be advised that prices are to be used as a guide only, as i acquired all my parts at "trade" price and G.S.T has been excluded

Replacement block $100:

When i pulled down a 308 i had, the bore size was already .40 thou over,had a broken oil ring and a big score in one of the bores,(see pic) this unfortunatley will not hone out, i had to make a decision on whether or not to bore the block out again to .60 thou(which is the maximum) or find a suitable replacement, a quick phone call to a mate,$100 and 20 mins later i had a standard bore 308 block in the back off the needed to be bored out but being standard bore leaves plenty of meat there to play with, The heads were L34 specs,crank and rods were to be used in the new block,also there were 2 types of rear main seal used in the holden v8 1 neoprene and the other a wick type, make sure that they are of the same type as the cranks are not interchangable!!! ie wick type crank will not fit neoprene type block!


===Boring of block $160:===
The new block i had just acquired was dropped off at the machine shop, a quick inspection by craig(machine shop fella) revealed that it needed to be bored out to .30thou, i was a little dissapointed as i only wanted to go to .20 but hey....he is the expert!!!


===1 precision engine rebuild kit $580===<

br />hypertec pistons, hastings moly rings, graphite head gaskets,sump gasket,inlet manifold gasket,vrs kit,rear main seal, kings main,con-rod and cam-shaft bearings.

i opted to go for dished pistons over flat tops, i also opted for the precision rebuild kit, consisting of all U.S made parts, they are better quality and that is what counts when building engines QUALITY!!!


New con-rod bolts $100:

New arp rod bolts were bought and delivered to the machine shop, i didnt want my new bottom end coming apart on me so i decided hey! new rod bolts!!! its only money!!!


New Jp oil pump $110:

Crow timing kit $95.45, lifters $72.00, new Heavy duty clutch $190


a new Jp oil pump was bought along with a new heavy duty clutch,timing kit and lifters the bottom end is nearing completion(parts wise) but there is still more money to be spent on fitting pistons to rods, rod bolts to rods and a full engine balance....keep going.


===new welch plugs $6.60, fitting of pistons to conrods $75.00, resizing of 1 conrod $20.00, fitting of new rod bolts $40.00, new ignition coil $45.68,new leads $45.00, spark plugs $24.40, oil (penrite) $48.72, oil filters X 2 $18.24, carb rebuild kit (650 holley) $85.00,distributor cap,rotor and cap ring $51.93, additional costs including hot tank of block etc $100.00===

as you can see by the list it does add up!!!! havent decided on cam-shaft as yet or had heads even looked at!!!!! money money money!!!


===crow 5651 cam 282 duration,.493 lift $200, new crow LT1 valve springs $73.63===

cam selected was a crow prt number 5651, fair amount of lift and duration with the cam kicking in at 2400rpm and running out at 5500rpm. New valve springs were needed to avoid spring bind when using a higher lift camshaft.


===full rotating assembly balance inc clutch,flywheel $330===

the whole rotating assembly was balanced to ease wear and tear on the bottom end, is a worthwhile investment.

with the bottom end back from the machine was time for assembly!!!!(see pics)


===full service of L34 heads $280===

heads were dropped off at another machine shop for servicing, see pics of before and afters, along with the new LT1 valve springs so they could be fitted whilst servicing.

ok engine bay time....we have a total cost of $2850+ G.S.T, tag on an extra ===$500=== for a machine shop to do your assembly,===$300-$400=== for a complete buggered 308, another ===$1000=== if you want L34 heads, valves alone are ===$17ea===, then machining of heads etc etc, and add another ===$900=== for a full set of yella terra roller rockers(not street terras), cost can vary greatly as it really does depend on what you already have ie I had a brock manifold,650 holley and L34 heads already in my shed so expect to pay if you want these options, so if you had to acquire a 308 have a machine shop do your assembly, wanted roller rockers and L34 heads you would be spending around $5650.65+ G.S.T.




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