My Road Trip Motor Progress
rick m:
Had my Sil Modesti aluminum motor breather powdercoated for easier maintenance, plus cleaned up the copper header exhaust gaskets in preparation for assembling the balance of the motor. Moving at a little faster pace now that it has cooled off. Morning and evening temps are no longer the killer 105+ temps. Nights and morning are now in the 70's which is car project weather.
RM [ Attachment: You are not allowed to view attachments ]
Torben Alstrup:
Hello.
Joel. Such an engine oughta pull those #´s anyway. The 122 is an aggressive lump of steel.
WRT the Salzburg engine. I seem to remember that the reason for them using the gutted stock exhaust were regulation in the class or something like that. Next, I have recently been involved in a supercharger project where we also ended up using a gutted and modified stock muffler, mostly to keep stock appearance and to fool the enemy. Now, I´m NOT saying that we could not have pulled even higher #´s with a good 4-1 header. But the performance and torque numbers of this engine surprised even me. But on the other hand, the peak power on this particular engine is also at 5100 rpm. Quite some way from 6700 rpm.
I do remember being said that the reason to them staying at 9 - 1 CR was due to the fact that they could not keep head temps in check on longer stages if elevated more than that, partly due to them having to run the stockish muffler.
Going back to the cylinder head design. One of the things I was looking at when I was working with the SH solution was how complete the burn was. And I was never able to get the ppm numbers down to what I thought was decent. They were always 15-20% higher than the same engine with a bathtub (!) good word ;D design. That is also what I see on the 616/356 engines. They have to run horrific high numbers in CO and ppm to run decent. It could be really interesting to find out how that looks in a more "modern" SH chamber like Ricks or Joels version.
The use of twin spark ignition in such a chamber would change everything. I have noticed a couple of 616/356 engines that runs twin spark. And suddenly they can run super clean emissions and idle CO can be cut in half, O2 numbers at WOT can be reduced along with a temperature drop in the heads and finally the power increase for these semi quick engines were 6-10 hp. Also look at the Alfa Romeo 1,8 & 2,0 engines. They came out with T-spark back in ´89. Compared to the sgl. spark version they pulled 10 hp more AND equalled Euro 1 emissions (Cat 1 to others) The increase in hp comes (off course) only partly from the improovement in the burn, the reduction in pumping losses and also the fact that the engine now can run typically 1 digit higher CR with out detionation plays a significant role. Now, the Alfa cylinderheads have a ball/dome shaped chamber with the plug right in the middle of the top. The addition of an extra plug all the way towards the side of the chamber on the exhaust side, (on the 16V models just between the valves in the side of the chamber) and firing it 2 degrees early, that way pushing the the rest of the unburned mix to the center of the chamber for a more complete and efficient burn.
On a bathtub type of chamber we more or less know the advantages of TS due to some people around the World have taken the time and effort to seriusly and scientificly explore this. Limbach does it on type 1/WBX heads, but that is from a safety point of view first over efficiency. From a leighman´s point of view I would expect the efficiency and emission numbers to improove in about the same rate as with a conventional chamber, leaving only the cylinderhead temperature issue open. I really have no idea whether that would improove the same way too or not. Theoretically it should, due to the lesser pumping loss alone, but that is pure speculation.
T
rick m:
Torben,
I will let you know on the CO numbers and emissions after mine is up and running. I will put it on the wheel dyno at Competition Engineering to test it out as we dial it in. I too am in the hunt for lesser cylinder head temps living in the arid, hot Arizona desert. We will see what the outcome is in weeks when I have it all back together.
Rick M
rick m:
No pictures yet but long block together, rockers on, engine tin, exhaust and other bottom end pieces going together. Was hoping to have ready for VEGAS but too much going on at work, etc. Will post pix when in the car.
RM
rick m:
Long block done. Rocker geometry done. Returned to using VW valve covers with the stock bales. Set them up with 1/2" tubing for my breather hoses. There are some opinions that the heads cool better with the stock valve covers vs. solid aluminum ones. I included a shot of the intake ports. Will finish up the top end this weekend. Slow but steady progress.
Rick M
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