According to my calculator, the Crower Level 3 (276*/281*/112*) installed 4* advanced (108* ICL) with 9.4:1 static yields a DCR of 7.48. 10:1 static yields 7.93
If you remove the hot spots in the combustion chamber such as the sharp edges around the chamber edge, sharp edges around the valve seats and the reference boss next to the spark plug hole, you may be ok with 10:1 and near 8:1 DCR. I would say optimum is 9.75:1. This will give you margin so the ignition timing can be fully advanced and give you maximum power. Total timing should be around 34 - 36 degrees ATDC If you have to retard the timing, the power loss is greater than what would be gained by the .25 point difference in compression. If you are going to leave the chambers as is then 9.4:1 will work just fine. Paul
I bought new Enginetech LH and RH offset rockers, old ones are not LH and RH and pushrods are really close to head. Rockers came in 4pcs packets and I noticed 4 rockers look different than 12 rest. Looks like they missing pressed face for valve tip, or is it really matters at all?
Thats up to you. Do you trust those parts in your engine for what you expect it to do. And what repairs you may or may not have to do again . I used sealed power rockers and shafts. And they have a right and left.
That question is somewhat confusing. Cross hatch marks normally refers to the cylinder's surface finish not the piston skirt's. What is Summit is trying to determine by asking you that? Are they asking about the condition of the cylinder?
I wouldn't use their technical advice to select parts. I've heard that they are just looking at catalog info (marketing hype) and might not have the best of training/experience. It might be best to do all your research and planning before simply calling them to order stuff. If you weren't out of the US I would suggest patronizing the ones willing to give expert advice, as that's why they are giving it.
i just got a Scott Brown cam ... awesome service and 189$ for a CUSTOM cam... scott is very helpful, plus the install is STRAIGHT since the cam is already a advance build.. I can recommend it compared to a of the shelf cam.
That is what they answered: "If a piston has cross-hatch marks, the side skirts around the wrist pin will have an "X" pattern." My old pistons have that x-pattern around wrist pins, my BIG question is what is the real difference? What is the magic about that x-pattern? Make piston stronger? Look cool? Im confused. My old pistons: http://m.summitracing.com/parts/uem-1746-040 Pistons I planning to order: http://m.summitracing.com/parts/uem-1736-040 1736 pistons are set of 6, and they said they cant order 2 single pistons unless I tell them exact weight and do I want them with or without cross hatch marks. How the hell I should know weight of pistons in set of 6? To weight question I tried to tell them I only want 8 same weight pistons and if they can affect to weight lighter is always better. I will get my crankshaft rebalanced anyway.
I guess they would have to weigh the pistons they are going to sell you and determine that themselves?
1749h set of 8 also says compression height 1.805 http://m.summitracing.com/parts/uem-1749h-040 Sealed power gives me over 10:1 compression, too much for crower 3.
Your link is different them mine . Mine is a kieth black piston and it list 1.835 but list this one as a single piston . One of them is a misprint. What's your piston depth with current piston
I checked other sites and yes the Keith black piston is only 1.805. Are your heads or block shaved or milled? The 340 in a stock block and heads with a felpro.045 gasket is barely 9.5 and that only due to .040 overbore
Yes heads are milled, chambers are 49cc. Do you know exact volume for 340 dish? Around 8cc? That gives me around 10.4:1 static compression.
No, you cannot just install it straight up, you still have to degree it to make sure it gets installed correctly. http://www.v8buick.com/showthread.php?220945-Camshaft-degreeing-101
340 is supposedly 10.5 cc. Compression is still high even with a retarded cam. I see where your at. Would not mind 49 cc on my 350 for the 310 cam that is currently in it. I do have a used level 3 cam I am debating on using. Not in a hurry to yank cam again.
Agreed! No, you should not simply "line up the dots". There have been instances where gears are mis-machined or dotted "off by one tooth", etc. It's not about squeezing the last .4 hp from it. It's more like making sure you aren't off by 16 degrees or whatever and then coming back to the forum with a question like, " Why won't my Buick run right..." or "All my valves are bent..." The machine shop is basically saying, "you don't have to use new engine oil, but I recommend it." :Brow:
