| Author | Message | ||
     Ezblast |
Done! | ||
| Bandito90 |
Hey,Guys I finally modified the valve guides and reinstalled the head.But the only thing now is the manual says to remove the head to get the lifters out to install the cams. | ||
| Ezblast |
 | ||
| Bandito90 |
I know I just assumed the lifters would come out through the case!My bad any body know what would be a good starting point for the jetting for when I first start it? | ||
| Berkshire |
You shouldn't have to do that - just remove the rocker box cover and the little rocker box screws, and back the larger rocker box bolts out enough to get some slack at the pushrods & lifters. When you put the cams in, you just need to hold the lifters up out of the way. Do you know how to check all the clearances? | ||
| Bandito90 |
Thanks,Berkshire.I'll try that.I'm hoping the manual or the info from the nrhs site will suffice.This project is taking long,But I rather do it right. | ||
| Berkshire |
I think their web site has a page telling how to check cam lobe, lifter, and piston-valve clearance. If you have a dremel with the flex-shaft and a 1/4" diameter carbide burr, you can do some minor head work yourself - look in the "replacement heads" thread around february or march. | ||
| Bandito90 |
They are b70 cams so hopefully not much will need to be done. | ||
| Ezblast |
According to Andrews the B-70 just need to have stronger springs for the increased lift and clearance checked - should be ok though - though both NHRS and our sponsors and us - we would all recommend new guides and seals as well. EZ | ||
| Bandito90 |
The guides are modified and the seals are new.I had all the parts cleaned at a machine shop. | ||
| Ezblast |
Sounds like your good to go! EZ | ||
| Gearheaderiko |
B70's should bolt right in without case interference. Berki: Dont you mean XB9 piston? | ||
| Bandito90 |
I got the cams in tonight.I just hope they are lined up correctly and not a tooth off!I put the cam cover back on,But the bottom middle hole seems to not line up.I'm wondering if they gave me the wrong gasket? | ||
| Bandito90 |
I got the bike back together!I will fire it for the first time tomorrow! | ||
| Berkshire |
I was told compression ratio would be WAY high (like 12 or 13) with an xb9 piston, and about 10.2 with an xb12 piston - I hope that's right! | ||
| Bandito90 |
Hey thanks for the help.I got the bike running today.It seems to run well.The only problem is there was a tap in the top end before I took the the motor apart..It seems to got louder.I'm wondering if there is something worn that I didn't catch? | ||
| Ezblast |
What oil you running? - try see if slipping a little Marvel oil in there - if it is a sticking lifter - that will quiet it for a bit, a collapsed lifter wouldn't work - and would sound real bad - I suspect a sticking lifter - unless your running Ti valves - ;0). EZ | ||
| Ezblast |
I'm not sure though - other thoughts folks? EZ | ||
| Ezblast |
Whats your jetting also - detonation? No leaks at the header or header gasket as well? EZ (Message edited by ezblast on July 28, 2008) | ||
| Berkshire |
Maybe a rocker arm or spring contacting the rocker cover? That shouldn't have been happening with the stock cams & springs though. Maybe a lifter that's a bit quick to bleed down and slow to pump up, if not a fully collapsed one. | ||
| Swampy |
Probably a lifter that is bled down. Give it a little time and oil. | ||
| Bandito90 |
Hey,I checked the plug after each heat cycle and and after the first run and it to be burning good.I will check the header again.I will pull the rocker cover if all else fails and clearance it if need be.Also I'm running andrews b70 cams.The sound is not really coming from the area of the lifters. | ||
| Berkshire |
it doesn't - bad lifters give valvetrain slack, so the noise comes from the rockers. | ||
| Bandito90 |
That makes sense because it seems to be coming from below the rocker. | ||
| Gearheaderiko |
Very doubtful the rockers are hitting if you had the noise before you did the cam swap. If you used different valve springs and they are bigger than the Blast springs (usually are), you needed to clearance the rocker box (valves springs only-lift is fine). Probably a lifter going bad. I'm really hoping you checked or upgraded (recommended) your oil pump drive gear. | ||
| Gearheaderiko |
"I was told compression ratio would be WAY high (like 12 or 13) with an xb9 piston, and about 10.2 with an xb12 piston - I hope that's right!" The Blast is 1/2 an XB9, same bore and stroke. The XB12 is a stroked XB9, therefore it needs a shorter piston than the XB9. An XB9 crank with an XB12 piston will give very low compression. An XB12 crank with an XB9 piston will give very high compression. You needed an XB9 piston  Correct me if I'm wrong. PS I also checked the box my pistons came in- XB9. | ||
| Bandito90 |
I'm going to replace the lifters and see if it improves anything.The oil pump gear seemed fine. | ||
| Gearheaderiko |
Replace them with something good, such as Jims Hydrosolids or Revolution Performance Hydrorev lifters (but then you'll need adjustable pushrods too- and if you do that,you'll need collapsible pushrod tubes, but then you can just cut the pushrod cover off with out pulling the head, again). Replace the oil pump drive gear with part#26391-06 high performance drive gear (stock on new Blasts). Early years were prone to failure and if it does it can take your engine with it, certainly at least the pump (which is $350? gear is $50). Its also a high performance weak spot. Easy to change especially since you'll be pulling the head off again to change the lifters (unless you installed adjustable pushrods). | ||
| Bandito90 |
I was going to ask about after market lifters.I decided I will get the oil pump gear and lifters.But I going to Germany next month and will have to wait till my finances are better. | ||
| Berkshire |
that's what I was thinking - 984cc/2 = 492cc; 3.500"x3.125" I'd intended to order the "9" piston. But apparently there's a big difference - the Blast having a "big twin" connecting rod that's longer than an XB or sporty rod. I was completely blindsided by this little bit of trivia, and not having the actual numbers needed to figure it out for myself(piston compression heights, con rod lengths, cyl heights, flywheel center to cyl base distances, piston dome/relief cc's, combustion chamber cc's), I just ordered the recommended 12 piston. It occurred to me later that the larger displacement of the 12 would need a smaller dome than the 9 to achieve the same compression ratio, and with 9/2 displacement I'd want the same dome that gives 10.5:1 on the 9, so I called back to check if maybe I shouldn't really use a 9 piston after all, but Dan told me that the 9 piston would give way too high compression due to the longer Blast rod and the 12 was indeed what I needed, but yes, compression would be a bit lower due to the smaller dome and it can't be helped. FRAKKK!!! this is what I hate about the world of H-D & Buell, and probably all MC's - all the tech is "dumbed down".  For my Ford, I can look at vendors and manufacturers web sites and see a chart showing all of the pistons for small-block ford, and all the crucial measurements for each one - dome cc's, weight, pin dia, compression height, ring sizes, everything - anyone building a motor can look at the numbers and pick out the right part for the job. This also allows comparison between one manufacturer and another. You can look up stroker cranks and connecting rods in various lengths, crunch the numbers, and figure out how much you'd need milled off the top of the block to get your quench clearance where you want it. You can even figure out crazy stuff like if there's a Chrysler piston and straight-6 Ford rod that will go with a 400 Ford crank into a 351 block to build a long-rod stroker motor. There is, but you'd have to get the big end of the rods narrowed a bit - now that aftermarket stroker parts are readily available, it's not worth the trouble. The point is that all of the needed info is readily available. If I had all the numbers for a P3, XB9 and XB 12 motor, I could figure this out myself - but aside from bore, there aren't any numbers to be found. It's like we're all too stupid to figure these things out for ourselves, so the actual specifications are hidden from public view and we have to rely on someone else to tell us what to buy. I was going to drop off the piston & spare jug at the machine shop tomorrow and then just do a quick top-swap when it was ready - simple, easy, quick... but now it looks like I'll have to wait until I have time to tear down the top end, measure everything, put it back together, cc the XB head, do some math, and possibly get a different piston. Frak! I love it when a good plan comes together!  |
