new build oil usage

[GHBiker]

 :wtf
I have put in a fueling oil pump, S&S cams, S&S 89 cc Performance heads, and Keith Black 10.6/1 domed pistons. This is in a 2005 Dyna Twin Cam 88. My mechanic asked me to do 1000 mile break in b4 we remap the motor, so I put on about 1300 miles below 3500 rpm. During that time I used just a little better than 2.5 quarts of oil. My mechanic and I did compression test and what he called a leak down test. The leak down wasn't a true leak down, just waiting a while to see if the compression bled off. The compression readings were 160 on the front cylinder and 170 on the rear cylinder. My mechanic, whom I trust, felt these were great readings and, initially, so did I. I have since been presented with the information that, with the equipment we installed, we should have readings more in the 200 and above range.

Any thoughts or comments from some of you experienced builders out there? Where do you feel my compression readings should be and where did that much oil go?
:

[rigidthumper]

Welcome to the forum. Need more info, such as cams installed, head gasket used, what is the dome measurement or part number of the pistons, bore size.

[koko3052]

As said, without more info...but that is a lot of oil. Always monitor the builds that I've done and consumption is negligible. Also a true leak down is needed.

[tdrglide]

Unless original tune was close,  1000mi is a long way to go before tuning. Much less 1300.

[kd]

Welcome to the forum. Need more info, such as cams installed, head gasket used, what is the dome measurement or part number of the pistons, bore size.

Piston deck height (if known) will also be helpful.

Unless original tune was close,  1000mi is a long way to go before tuning. Much less 1300.

I agree.  For some reason some "tuners" will dump in a "starter or breakin tune" without confirming AFR or timing and that can cause cylinder damage resulting in your symptoms real quick. 

[1workinman]

:wtf
I have put in a fueling oil pump, S&S cams, S&S 89 cc Performance heads, and Keith Black 10.6/1 domed pistons. This is in a 2005 Dyna Twin Cam 88. My mechanic asked me to do 1000 mile break in b4 we remap the motor, so I put on about 1300 miles below 3500 rpm. During that time I used just a little better than 2.5 quarts of oil. My mechanic and I did compression test and what he called a leak down test. The leak down wasn't a true leak down, just waiting a while to see if the compression bled off. The compression readings were 160 on the front cylinder and 170 on the rear cylinder. My mechanic, whom I trust, felt these were great readings and, initially, so did I. I have since been presented with the information that, with the equipment we installed, we should have readings more in the 200 and above range.

Any thoughts or comments from some of you experienced builders out there? Where do you feel my compression readings should be and where did that much oil go?
:

Ok I going to repeat what I learned and paid to have done . I want my motors built a certain way , and knowing the compression is one of them .  .    I like and want the cylinders honed with a torque plate. Heads are in good shape . My heads that are on my 124 were done by Mega Flow , very nice work .  I for one want my motor assembled after all of the work is done , heat cycled and then on the dyno .  only way I want it done , I want to know the details of the build . I use some one that I know does these things .  Let me tell you why ,  I experienced some of that crap pistons hitting the valves on just assembling the motor and not checking a damn thing probably . The reason both of my motors were done at GMR now .  I want the engine tuned after heat cycled because you can do a lot of damage to the motor not , if the fuel curves are not right and timing. Can you tell where the oil is coming from , front or rear cylinder .  .   Now to be fair your not over filling the motor right . is the motor sumping . . From a problem with the oil pump

[HD Street Performance]

You say this is a 88". Were the new pistons put in the stock bore cylinders? How were they honed?

[tdrglide]

Which S&S cams?

[Scotty]

You need to get the compression and leak down test done again and done properly by someone different other than the original mechanic.
2.5 quarts of oil is a lot of oil.

[HD Street Performance]

I agree up to a point. The can leak ok and still have oil control problems. Carry over usually is there in these cases

[1workinman]

I agree up to a point. The can leak ok and still have oil control problems. Carry over usually is there in these cases

  Yea I was thinking that to like giving the cylinder a shot of oil or two to check compression after checking it dry 

[Scotty]

I agree up to a point. The can leak ok and still have oil control problems. Carry over usually is there in these cases

Yes but to put domed high compression pistons in and end up at 160 & 170 seems a little strange IF he was going for performance and using S&S heads and cams you might think that was his aim.

[GHBiker]

Thank you for all the responses. A lot of that info I do not have. The cams are S & S 510 C, the honing was standard cross hatch honing, The heads are S & S 89 CC performance heads, The plugs are light tan and seem to be burning properly, although the pipes are sooty. Todd, my mechanic, has built a number of performance engines. He admits he cannot explain the oil consumption, but has assured me that, if we go ahead with the remap and dyno, a costly affair, and something fails he will stand behind all of it, rebuild, reremap, and what ever else is necessary. I have ordered a leak down tester and a bore scope as he does not have either. we will employ them before we go forward with the remap.

[rigidthumper]

OK, looks like you have KB343,  16.8cc dome, 3.75 bore pistons. Supposed to yield 10.6:1 cr with a .040 head gasket & a stock head.
Seen in Pic1. Should crank about 188.

You have S&S 89 cc heads installed, which lowers the compression to 10.11
Seen in Pic2. Should crank anout 177.

[HD Street Performance]

All straight now. Thanks Robin.

And that said fitting stock bore pistons in used holes is marginal at best.
Putting new pistons in a used bore without going oversized is usually a failure. Guys ball hone them. The bores usually are not worn much but they are not straight and true. To get them straight and true in a fixed hone will result is a loose fit and that has issues as well.

Best fix is to go up to 95" especially with those heads. Now mill the heads and use a .030 HG to get the compression up a little.

[1workinman]

All straight now. Thanks Robin.

And that said fitting stock bore pistons in used holes is marginal at best.
Putting new pistons in a used bore without going oversized is usually a failure. Guys ball hone them. The bores usually are not worn much but they are not straight and true. To get them straight and true in a fixed hone will result is a loose fit and that has issues as well.

Best fix is to go up to 95" especially with those heads. Now mill the heads and use a .030 HG to get the compression up a little.

  Correct me here also . You install the rings in a out of round bore and the rings transfer heat at the places it contacts the bore so the results are not good . The top ring gets cooled from the intake charge the second runs hotter and will grow . Best is to have straight bores and fitted correctly pistons and ring gaps , heat cycled and tuned

[HD Street Performance]

Exactly.
They break in fast when the hone and fit is done properly and they get the low speed ranges AFR fixed on the dyno. There is stop and starting and fans for cooling. Heat cycling done safely between uploads.

Robin
Checking a little deeper
510 cam (38° ABDC close) and assuming a stock head gasket at .045 x 3.85 plus a .006 deck it would be 9.13:1 corrected (9.88:1 static) and crank 188# nominal and a little lower when adding in the compression space from the top ring up.

[rigidthumper]

Correct, Don.
The data I used was from KBs site- they allow 15° after advertised close ( which is measured at either .050" or .053")
 I do not know if KB uses total volume above the top ring or just the dome minus the valve relief.

[HD Street Performance]

With domed pistons they list the "Crown CC" as a negative number, in other words this is what is taken out of the combustion space. So dished pistons are a positive number. The other number they show in the description "Dome [or Dish with a +]" -XX.X CC is the net after taking the reliefs into consideration.

All that said there are mistakes and to their credit Marco, their Harley guru, is a very sharp nice guy. He wants to get all the data right on this new site.

[GHBiker]

I will follow up on all that has been presented tomorrow. Today is for the Drs.  They have to make their money to put their kids through college.

[GHBiker]

   I finally got to using the new leak tester and the bore camera and we found no leaks and with the camera and scope the cylinders look beautiful and like they are just starting to seat. No high spots, no low spots. there has been no oil usage in 120 miles and the pipes are clearing up We are going to go ahead with the remap and dyno and hope for the best.

My deepest appreciation to all who tried to figure out this conundrum with us and offered excellent advice. Thank you very much.

[kd]

By the sound of it all, you may have had all of the rings line up on a piston and they have finally rotated enough to stop pumping oil.  My guess is it was likely the rear cylinder (but cross feeding in the manifold when in overlap) due to the slightly lower CCP reading.  It's rare but it happened to me on the dyno.  That would be my guess if it stays cured.