valve clearance

[roy95]

  Build is 95 bb 9.4to 1   heads are milled to 80.5 cc that 046ths milled off. Valves are stock 2005 heads ported and polished compression set at 9.8to 1 ,, cams are Andrews 37g my  question is would there be enough clearance for me to install a set of se 1.752 hi ratio rockers . Thanks ..

[torqueinc]

 What pistons ?

[djl]

Only one way to know for sure; mock it up and check.  You can mock it up with the stock rockers; measure and you will know if there is sufficient clearance for the higher lift.  I suspect you will be close and they will work but, only way to know for sure is to measure.

[roy95]

the piston are screamin eagle flat tops   was hoping that i would not need to remove heads to measure  piston are 22851-99a

[djl]

OK, I'll put it to you this way.  Would you rather mock up and be sure, or take your chances on getting lucky or rebuilding the top end? 

I suppose you could run some .060" solder into the chamber through the spark plug hole and try to get a measurement that way; has been done before.

The smart move would be to mock up and measure. JMHO though; your ride, you decide.

[baker]

It's sounding kind of risky, with a stock head and the 37 cam you should have about .081 clearance piston to intake valve on the intake stroke, but .046 has been removed from the head so that still gives some clearance but it is under the minimum safe clearance of .060, you could assemble one cylinder and clay the set up on the intake valve and measure your clearance to be sure, if you add the 1.725 rockers your clearance will be another .011 less than your measurement with stock rockers

[roy95]

    OK i get it,, there is only one way to know for sure and I already have less then the safe minimum so for me it will be the 98 kit with the 9.7 to 1 flat tops ,,I do all my own work and I learn as I go , so if it seams that I ask a lot of questions that's why . I want to be sure that my next dyno is over 100/100.  See my dyno run in the dyno section. As for the tune it is a 5 hour drive to a good tuner. I need some help to get to where I want to be..

[hogmandon]

get some 50/50 solder and slip over valve cut out on piston as mentioned above, turn engine over by hand. Do not use starter. How far were pistons down in the hole or was  deck at 0. What head gasket

[djl]

OK i get it,, there is only one way to know for sure and I already have less then the safe minimum so for me it will be the 98 kit with the 9.7 to 1 flat tops ,,I do all my own work and I learn as I go , so if it seams that I ask a lot of questions that's why . I want to be sure that my next dyno is over 100/100.  See my dyno run in the dyno section. As for the tune it is a 5 hour drive to a good tuner. I need some help to get to where I want to be..

I am confused.  Your first references to static CR were 9.4 and 9.8 static CR.  You have also indicated that the work was done because you didn't want to remove the heads for a mock up. Now you say the build "will be" 9.7 static.  Have you built the motor or not?  If not, what's the issue with a mock up?  Mock it up to check deck height, squish and piston to valve clearance.  You may be able to run the high ratio rockers.  I know it's under the "safe" limit but I have been running a 95" with .040" clearance on the intakes for nearly 20K miles with no issues; not a recommendation but my first build a few years back and I didn't measure before having .065" cut from the heads.  Lesson learned; every top end gets mocked up and measured and I will always know what can or cannot be done with a particular top end.

[roy95]

When the build was first done I used 95 big bore with 9.4to1 flat tops 37g cam forum members said my compression was to low so I sent my heads out for port and polish set compression 9.8to1 ,,had bike dyno ed wanted to make 100/100  but did not if i cannot do that with cam lift  I will install a 98 kit that is 9.7to 1 with my 80.5 heads that should do it.. if i could fine a dyno run with that  build that may give me the information i need, if i take the motor apart to mock up,, new 98 kit  will go in, will stay with cams just though the rockers would be easier

[sfmichael]

    "if you add the 1.725 rockers your clearance will be another .011 less than your measurement with stock rockers"

 ??

not following this thinking, won't the high lift rockers add about .030 additional lift at the valve?

[djl]

When the build was first done I used 95 big bore with 9.4to1 flat tops 37g cam forum members said my compression was to low so I sent my heads out for port and polish set compression 9.8to1 ,,had bike dyno ed wanted to make 100/100  but did not if i cannot do that with cam lift  I will install a 98 kit that is 9.7to 1 with my 80.5 heads that should do it.. if i could fine a dyno run with that  build that may give me the information i need, if i take the motor apart to mock up,, new 98 kit  will go in, will stay with cams just though the rockers would be easier.

Don't need high ratio rockers to hit 100TQ.  Last 95" build I did for a friend ran a set of '07 heads, no porting but cleaned up, new guide seals, OEM springs and valves and SERDI multi angle valve job, decked for 9.8 static,  SE flat top pistons, 37 cams, Rinehart Crossbacks (not known for power), SERT tuned to 96HP/102TQ.  Had he ported the heads, maybe he would have seen 100/100.  I have seen dyno charts of the same build with WFO Larry's Stage II heads that made 100HP/108TQ, pretty sure it is posted in the dyno section of this forum.

[baker]

    "if you add the 1.725 rockers your clearance will be another .011 less than your measurement with stock rockers"

 ??

not following this thinking, won't the high lift rockers add about .030 additional lift at the valve?

Yes the high rockers do increase the valve lift, most of the valve lift occurs as the piston is going down the hole on intake, I was only referring to the increased valve lift at TDC where valve to piston contact could occur resulting in engine damage

[sfmichael]

    "if you add the 1.725 rockers your clearance will be another .011 less than your measurement with stock rockers"

 ??

not following this thinking, won't the high lift rockers add about .030 additional lift at the valve?

Yes the high rockers do increase the valve lift, most of the valve lift occurs as the piston is going down the hole on intake, I was only referring to the increased valve lift at TDC where valve to piston contact could occur resulting in engine damage

I see