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304 VN AERO REBUILD (304 stroked to 350ci flat top pistons std 4" bore)

gtrboyy

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AV8 has good info so too griffs rear mount turbo on yt has what he's learned from there too.

Bare minimum since you're deburring I'd weld up cam bolt hole & timing chain oiler then look up porting stock oil pump from 2 sources above.

If going performance route or game enough look up oiling system mods by Come Racing on YT for brief on oil passage mod & cam bearings...it's what should havew been done by factory.
 

bjf66

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Griff's video is good, much more detailed than Come, easy for some of us to follow

  • managed to get the #1 cam bearing out with socket
  • have ordered universal cam removal/install kit, probably take a week to get here
  • tapped the 3 frost plugs with 3/8" BSP
  • opened up the oil pump in/out holes from 9/16" to 15mm drill (had no 16mm drill as Griff had suggested). Gave them a little sanding with scrolls to clean them up where change of direction is located
  • drilled the 2nd hole on front of block cam bearing to feed priority oiling down LH side of block
  • drilled both priority feed holes to 6.5mm Dia
  • ground the annulus, taken down to approx. 4 O'clock looking at the block
  • there is no cam chain oil hole on my block

  • just need to plug #4 cam bearing, as its feed from the priority feed now
  • drill mains feed holes to 6.5mm from 1/4"
  • then look into oil pump

  • ordered the ACL piston rings M9104 today
 

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Immortality

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Griff is a nice guy, it's a shame He let politics into his videos.
 

gtrboyy

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Damn dude that is rapid progress.

You must be work from home or stuck there at this rate.

You calculate differences a 308 versus 304 crank will have on compression ratio?

Can't remember the outcome or if there was a conclusion to that during AV8 days.
 

bjf66

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yes work from home
takes mind off all the BS going on with Covid
welsh plugs and ACL cam bearings 5C5146C ordered

need to get the remaining cam bearings out, then drop block off to get decked, hopefully turn around wont be that long, been quoted $250, try and drop off next week at latest

need to polish 304" crank, however at present cleaning up 4.25" BBC crank so need to get that out of way first
 

bjf66

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so seems the 304 flat top piston into 308 bore is durable and nets nice increase in compression ratio
308 Compression height of piston: 1.68"
304 compression height of piston: 1.71"
so 0.030" difference
304 piston FT put in 308, your top of piston would be 0.003" down from deck height, based on the previous measurement for my block which was 0.033" deck clearance
so 9.78:1 without decking block with standard VN 63cc heads

or another way would to take 308 crank and stick it in 304" engine this would be reasonable cost effective given the amount of 308 cranks floating around


Bore: (diameter) 4 in.
Stroke:3.06 in.
Cylinder Head Volume: 63 cc in.
Effective Dome Volume:
Use (-) for Dome and (+) for Dish.
0 cc
Deck Clearance:0.003 in.
Compressed Gasket Thickness: 0.040in.
Number of Cylinders:8
CALCULATE​
Compression Ratio :9.78 : 1
Total Displacement (in.3) :307.63
Total Displacement cc's :5043.11
 

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  • there is no cam chain oil hole on my block
The hole is in the centre of the cam shaft retaining bolt. This bolt is blocking the end of the LH lifter oil gallery.
It bleeds off a little pressure and is squirting the cam chain.
I think they say that the chain is getting plenty of splash oiling so this isn't necessary. Or change the direction of oil to spray the oil pump drive gear instead.
 
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gtrboyy

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When viewing engine from front look at 2 o'clock position near 1st main journal...what is that?

Yes cam bolt is another pressure leak...oli pan/crankcase etc should have enough splash to keep it all happy.

Several cool ol' tricks to keep these alive like if run roller rockers less oil required....roll pins into pushrods to restrict flow or old heads use to close up holes on lifters drill to smaller size instead of expensive edge orifice lifters...probably nla these days.

Heaps of forgotten mods can still do although it'll already handle more than want it to make with current mods lol
 
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Immortality

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Do you mean the timing chain oiler?
 
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