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ThinAir |
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Best friends ![]() ![]() ![]() ![]() Group: Members Posts: 2,546 Joined: 4-February 03 From: Flagstaff, AZ Member No.: 231 Region Association: Southwest Region ![]() ![]() |
This started out as this topic: http://www.914world.com/bbs2/index.php?act=...=ST&f=2&t=28067
It seemed like a good idea to start a new thread with different subject. The 2.0L engine I'm building is using stock crank & rods with stock size (94mm) Euro flat top pistons. My understanding from other topics is that when you build such an engine you get slightly higher compression than stock because of the flat top piston, but you basically don't need to change anything else. When I put the first piston & cylinder in place I used the .007" barrel gasket that was included with the overhaul gasket set. I measured the distance from the top of the piston at TDC to the top of the cylinder at .022" I don't have the actualy head cc measurement, but the paperwork for getting my heads done says they were cut .005". I don't know for sure if that is just this time or if the final cut is .005 including any cuts done during previous rebuilds. Using the math formulas and various calculators mentioned in the previous topic, I figure that if I assemble the engine this way I'll end up with a compression ratio of about 1:8.2 or 1:8.4 This engine will use the stock D-jet FI. So my question is: is it ok to assemble the engine with what I have or is this compression too high? If it's too high, what should I be shooting for with Euro flat top pistons? If I need different barrel spacers to reduce the compression, it's fine with me, but I don't want to just pick some number out of a hat or build it this way without knowing that it's ok. |
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ThinAir |
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Best friends ![]() ![]() ![]() ![]() Group: Members Posts: 2,546 Joined: 4-February 03 From: Flagstaff, AZ Member No.: 231 Region Association: Southwest Region ![]() ![]() |
With the help of a 60cc syringe from the local feed store, and some wheel bearing grease to stick down the plexiglass, I remeasured last night. The head for all the cylinders measures 56cc, not 59cc as previously measured.
Although I knew there could be some innacuracy due to using a 10cc syringe and refilling it 6 times, I'm amazed at how far off it was. Just to be sure, I measured them all twice. So using the calculations, this means I need .060" barrel shims. This will give me 8.1:1 compression. Jake - if you see this, I placed an online order for the shims. I tried calling and leaving a message, but everytime I punched in 3 as directed I just got cut off. Thanks to everyone for their patient advice to help me figure this out. I'm gonna have an extra (IMG:http://www.914world.com/bbs2/html/emoticons/beer.gif) on behalf of the group when it's finally back on the road as a way of recognizing that I could not have done it without you all! This post has been edited by ErnieDV: Apr 8 2005, 05:01 PM |
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