Another motor semi build thread

Reply Subscribe

Thread Tools

Search this Thread

Jul 17, 2017 | 11:52 AM

misfitJason

Thread Starter

Seasoned HDF Member

Joined: Dec 2010

Posts: 6,849

Likes: 1,389

From: Florida

Another motor semi build thread

I kept getting weird intake leak like symptoms but could never track it down totally. I did a compression test following seeing oil in my intake ports. Compression was good but I had the symptoms of rings seal issues, steam vapor coming out of the oil cap when running, erratic rough idle, and my ccp went up when oil was added to the cylinders. So I had my original cylinders (88 inch) machined to fit new pistons and we will try and break this thing in again.

Edit: motor specs
2006 Superglide
95inch running at 9.8:1
Timken conversion to crank and welded crank pin
Andrews 37h cams
Veetwin performance street port heads decked to 80cc with mcrs
Thunderheader
3.9 25 degree injectors (too small)
Wfo larrys lifters with s&s pushrods
Tts (and Powervision.....don't ask) tuned by doc

Last edited by misfitJason; Jul 17, 2017 at 01:51 PM.

Jul 17, 2017 | 12:14 PM

Tommy C

Seasoned HDF Member

Joined: Oct 2015

Posts: 13,489

Likes: 34,581

From: Pine Flat Dam/South Bay Area, CA

Don't neglect to replace the valve guide seals.

Jul 17, 2017 | 12:46 PM

F86

Outstanding HDF Member

Joined: Mar 2015

Posts: 2,840

Likes: 900

From: Philly Suburbs

Quote:

Originally Posted by Tommy C

Don't neglect to replace the valve guide seals.

Yeah, I was gonna mention this too... Did you notice any burning oil smoke at all from the pipes? If so, was it more prevalent at start-up, or under power? I had a small touch of both...

At any rate, it's a good project! Did you increase displacement beyond what was needed for honing?

I never get tired of looking at pictures of people's motors being taken apart and put back together...

Jul 17, 2017 | 01:34 PM

misfitJason

Thread Starter

Seasoned HDF Member

Joined: Dec 2010

Posts: 6,849

Likes: 1,389

From: Florida

Quote:

Originally Posted by Tommy C

Don't neglect to replace the valve guide seals.

I have new heads. Well, semi new. I had veetwin performance port polish and deck a set of heads when I thought it was a valve guide issue. I put them on and still had the same problem.

Jul 17, 2017 | 01:39 PM

misfitJason

Thread Starter

Seasoned HDF Member

Joined: Dec 2010

Posts: 6,849

Likes: 1,389

From: Florida

Moving along today. I am awaiting my buddy for a second set of hands to put the cylinders on. Oddly enough I was really not looking forward to putting the piston pin clips in but it went pretty smooth. Notice the black heads in the previous pictures.

I had the motor set up at 9.8 compression with mcr's, 95 inch, and 37h cams. I like this combo and that's what it is going back to although the previous set of heads were acrs

With the pictures of the previous pistons and cylinders you can see that, I am guessing either the tune was off (probably) and I babied it to much on break in and the walls got glazed plus the rings didn't seat. Second times a charm.

Even though it had ring seal issues the motor is quick. I hope now it will be quicker

Jul 17, 2017 | 01:41 PM

misfitJason

Thread Starter

Seasoned HDF Member

Joined: Dec 2010

Posts: 6,849

Likes: 1,389

From: Florida

Quote:

Originally Posted by F86

I only maybe like vet saw a little at startup. My biggest thing that I always saw was a very erratic afr at idle and under low loads. Then the oil in the intake ports. My breathers are vented externally and it always smelled super rich. My plugs looked a little damp. Not wet and not lean but like it was burning a tiny bit of oil.

What I used before was a 95 inch screaming eagle cylinder kit. This time I used my old 88inch cylinders to fit new 95 inch screaming eagle flat top pistons