12 November, 2008

Motor Build: Parts are arriving

So I pretty much blew through the tear-down of the spare VW motor without taking a single picture. Because of that, I'll try to snap pics of the new parts, alongside their used counterparts.

As a quick intro to this project, I'll start by saying I had grand plans very early on of building a monster race motor. But after a year of driving the FV, I don't really think it needs or wants triple digit horsepower levels. It is pretty damn fun and exciting with the 55-60hp it's little 1200cc heart pumps out now. In reality, it just needs a little more oomph to run down the straights at Thunderhill. I figure, if I can run with the Miatas and Civics down the straights, then I'll be able to stay ahead through the corners as I do now. So maybe 10-15 more horsepower? As an aside, this motor won't be legal for FV competition. but since I run with a local club it won't really matter. they use rules based on power to weight, with no regard to SCCA FV rules. Yes, I could build a 200hp monster and still have a class to run in.

I have had this stock (yet freshly rebuilt) 1600cc dual port engine in the garage. I figured just the extra 400cc alone would give a nice boost, as would the better flowing heads. I also was given a nice Weber 38 DGAS two-barrel from stepbrother Mark, and went about rebuilding it. That should give nice gains over the 28mm single-barrel Solex. In addition to the same headers and exhaust on the car currently, I think 70-75hp is very realistic, with a corresponding bump in mid-range torque. In fact, it could end up slightly higher then that, because well...I couldn't say no.

I tore down the 1600DP last weekend, measured everything, and went over my list of parts to purchase. While I don't intend to make a high reving race motor, I wanted to build up a good solid bottom end, with the top end capable of supporting sustained revs. Nothing fancy, but enough to hopefully keep it together.

I won't paste in the entire list of parts, but the key items I purchased include a counterweighted forged crank, hotter cam (might as well put it in while I have it apart) and I spent some time porting the heads. I of course got a full set of new bearings and gaskets, along with some smaller items like new pushrod tubes, high rev valve springs, new valves, and some useful tools.

So without much more babbling on my part, here are the contents of package 1:

Old 69mm stock cast crank on the right. New forged 74mm crank on the left. Note 8-dowels for the flywheel (vs 4 dowels stock) and the much larger webs for the counterweight effect, which smooths out higher rpm operation.

So yes, I got a stroker crank. About the smallest stroke you can get, so to speak, but that also means I shouldn't have to mess with case clearancing or longer connecting rods. Instead of 1586cc it will have 1699cc. 500cc moe than the 1200 in the car. Oh, and it was the same price as a 69mm crank, so what the hell. I alo got a set of barrel spacers, as the longer stroke pushes the piston out the top of the barrel. The spacers wil help me set my deck height. I'll get a slight bump in compression from this combo. 8.2:1 instead of 7.5:1. I always have the option of flycutting the heads should I want more compression in the future, but for now, I'll just be happy to run 87 octane gas. In reality, the heads will be the limiting factor with this engine. But considering it talkes about 30 minutes to pull the heads, I can always go crazy in the future.

Stock pushrod tube on the left, "windage" style pushrod tube on the right.

The pushrod tube connects the cylinder head to the case, with the pushrods running through them. During hard cornering, oil can slosh up into the tubes and run into the valve covers. Oil is good, however, the rocker arms already have a source for oil, so having pools collect in the valve covers does no good. Small leaks from valves covers seems to be a constant fight with VW motors too. I reduced mine significanly by going to kick ass composite rubber gaskets and bolt down valve covers, as opposed to the stock style clip on covers. However, for a whopping $18, the windage tubes should practically eliminate the issue. Because the end of the tube sticks out into the case more, oil won't have a chance to slosh up into them. That's the goal anyways!

My second package should arrive tomorrow. So stay tuned for more exciting pictures.

Oh, and that reminds. I ordered this stuff at noon yesterday. CBPerformance sent this package in 24 hours. SoCal Imports says the second package should arrive 48 hours after ordering. Assuming it does show up, I might get to spend some time this weekend doing assembly.


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