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Gympie
| Posted on Monday, September 27, 2010 - 11:29 pm: |
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Just did a squish check on my new build using a Cometic .030 set with head and base gasket. Using .063 solder on the shelf, I get no compression on any of the solder. What is the stock squish clearence on T-Storm/Piston set up? Over .063? Thanks, Gympie |
Sportyeric
| Posted on Tuesday, September 28, 2010 - 04:11 am: |
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Oh my sorry tale can be read here: http://www.badweatherbikers.com/buell/messages/384 2/451316.html?1272116118 The relevant info is Pammy's at the bottom. Others with more knowledge than I will weigh in, but if I could do mine again, I would measure, as you have done, deck 35 thou if you are confident of your measuring, check again, then cc the chamber volume and enlarge if necessary to keep to 65cc (?) or more. (Which should give 10.7:1, if I remember correctly.) I have built my Sportster engine in this fashion and am extraordinariy proud of its performance. |
Gympie
| Posted on Tuesday, September 28, 2010 - 12:07 pm: |
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Going to do a squish check again using a larger dia. solder, say a 0.090 to see how far I am off. Not willing, as the post above, to mill the heads as the added expense of getting adj. pushrods and new covers. Have been told that a .025-.030 is optimum but even up to .090 it will only give up 3 bhp which I can live with. |
Sportyeric
| Posted on Wednesday, September 29, 2010 - 01:27 pm: |
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Harley sells pushrods that are 50 thou shorter than stock, so you wouldn't need new pushrod covers. Stock lifters have a fair bit of leeway in them and if you haven't changed the valve seats, you can deck the heads quite a bit and simply let the lifters be compressed close to their bottoms when cold. As the engine heats and expands, the lifter will operate as it should. The play at the other end of the range, shortened by decking the heads, would only be used up by recession of the valve seat into the head as its pounded in over time. On used heads, I don' think that there would be much effect in that area. If you are checking squish again, you could also reinstall the rockers and check how much play you have at the rocker-to-valvestem, do the math and figure how much more room there is to compress the lifter without ill effect. I decked my Sportster's S1 Lighting heads 33 thou and run stock pushrods. So far so good. |
Scott_in_nh
| Posted on Wednesday, September 29, 2010 - 02:11 pm: |
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Not willing, as the post above, to mill the heads According to NRHS, you adjust squish with head and base gasket thickness, other modifications should not be needed. setting your squish clearance |
Gympie
| Posted on Wednesday, September 29, 2010 - 02:23 pm: |
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Decided to have NRHS mill the head anyway, hoping Dan will know what he is doing. He states that .050-.060 may have to be taken off. Won't know until he does it. Just tick's me off that the Motor Company would sell T-Storm heads in the condition they are. So ending up buying adj. pushrods and since I have not decided on a cam as yet the adj. pushrods will pan out. Oh BTW, Edelbrock has a great closeout price on the pushrods. Wish I could have gotten in on the price of their carbs, but sold out. Now shopping for pushrod covers. Think I'll go with the Zippers setup. Too many people are having problems with the NRHS Hurricane covers with leaking at the base. He suggests using super glue to seal them. :-) Had a conversation with Ken Weber of 10Litre Performance yesterday about squish. His opinion on squish is not to go below .040 on a street bike. This would allow for piston wobble, expansion of the rod and carbon build-up. Thanks for the suggestion on doing the rocker to valve measurement. Will do it. |
Gympie
| Posted on Wednesday, September 29, 2010 - 02:27 pm: |
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Yo, Scott. Talking about T-Storm heads here which have a nasty deck casting on them. Take a look on NRHS's site for more information on them. |
Scott_in_nh
| Posted on Wednesday, September 29, 2010 - 02:51 pm: |
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ok, sorry to post info that was useless to you - sounds like you have a plan in place. good luck! |
Bluzm2
| Posted on Wednesday, September 29, 2010 - 03:08 pm: |
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Gympie, You don't use the super glue to seal them, its used to hold the seal in place for installation. Four small dots around the perimeter is all that's needed. |
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