Building Chevy 4.3 liter V6 - 1994 with balance shaft
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'''PISTONS''' | '''PISTONS''' | ||
| − | 2016-03-30 Today ordered custom pistons at JE-Pistons | + | 2016-03-30 Today ordered custom pistons at JE-Pistons - and had to cancel the order again. |
| − | The new piston pins will be full floating at 0.925" diameter to fit on standard rod's small ends. We will use wire locks as the dual spirolocks would be overkill on a street engine which I will hopefully not rebuild a second time. I hope to use the Blazer to haul parts around and not fix it again. Because of the rather tame target rpm we're not going crazy with the rings. Just ordered them as file fit's to define gaps when building it. | + | We found out that the stock pistons will not achieve the squish we are aiming at. But in order to order the correct pistons I have to test assemble the engine with the correct parts. This means machine the heads first. |
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| + | The pistons will be forged flat top with two valve relief pockets for the V6 (means a set of 6). We're running the risk as we had to get the compression distance (CD) right in order to achieve the target 10:1 compression ratio (CR). The stock pistons sit so low below deck that the standard 1.5" CD did not work out. Even the available shelf pistons with a CD of 1.565" is not even close enough to reach 9.7:1. At this time we're aiming at zero deck height with a 1 mm (0.04") gasket uncompressed so we get an ideal 0.85 mm (0.034") compressed gasket thickness. | ||
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| + | It will be interesting enough to see what the squish will do once we get it right. The OEM stuff is a joke and will not produce any pronounced squish. I have nearly a 1/4" distance to the heads flat portion from the dish and 1/8" at the edge of the dish. | ||
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| + | The new piston pins will be full floating at 0.925" diameter to fit on standard rod's small ends. We will use wire locks as the dual spirolocks would be overkill on a street engine which I will hopefully not rebuild a second time. I hope to use the Blazer to haul parts around and not fix it again. Because of the rather tame target rpm we're not going crazy with the rings. Just ordered them as file fit's to define gaps when building it because of the forged pistons. | ||
'''TIMING SET''' | '''TIMING SET''' | ||
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The block turned out to be quite nice. Decks are very straight may need machining just a couple hundredth's or so - talking in mm that means just a couple thousandth's in inches. Turned out that the deck height was 9.025" at my reference point at #1 cyl. | The block turned out to be quite nice. Decks are very straight may need machining just a couple hundredth's or so - talking in mm that means just a couple thousandth's in inches. Turned out that the deck height was 9.025" at my reference point at #1 cyl. | ||
| − | The bores are the same. They just need honing 0.001" over which is about 0.02 mm. This with forged pistons at 4.000" will give just the right clearance and save me money. | + | The bores are the same. They just need honing 0.001" over which is about 0.02 mm. This with forged pistons at 4.000" will give just the right clearance and save me some money. |
| − | The big question now is if to use aftermarket billet main caps and drill the engine block now for a 4 bolt cap pattern or save that money for the next build. The answer to this is " | + | The big question now is, if to use aftermarket billet main caps and drill the engine block now for a 4 bolt cap pattern or save that money for the next build. The answer to this is "NO", not at this time. The next build may include this modification but aiming at some 250 hp does not require such measures. |
=== MACHINE THE HEADS - PORTING === | === MACHINE THE HEADS - PORTING === | ||
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