compression release options : V-Twin Forum: Harley Davidson Forums

gerry81611 · 03-18-2005, 09:51 PM

hey,

just picked up a 2004 FXSTB from a dealership mechanic. he juiced the motor up pretty good, but didn't drill the heads for compression releases (go figure).

the bike has SE-258 Cams, Crane Adjustable Pushrods, 1550 Cylinders Bored over .005, SE .005 over High Compression Pistons, .060 milled off of Heads (all clearances checked and within spec of HD), Port and Polished Heads, Stainless Steel 1 Piece Valves withs High Performance Valve Springs, Performance Clutch Spring, Vance and Hines Sideshot exhaust, SE Air Cleaner Kit, and SE-ignition module.

supposedly the bike has 11:1 compression, which is a little higher than i might have done myself, but the bike runs on pump gas.

for whatever reason, when the guy was doing the motor work he didn't drill the heads for compression releases. i assume (tell me if i'm wrong) that i will need compression releases.

so what i am trying to figure out is how to go about getting them in there. there is always the full price route of having the dealer take apart the motor and drill the heads, but i had heard that there might be other options. particularly one of the parts guys was talking about a tool that screws into the spark plug holes and allows the heads to be drilled while on the bike. anyone out there heard of this? opinions?

should that be all i need to do, or would i want a high power starter and battery too? i should note that i'm not having problems with the bike right now, but don't want the starter to fry in the middle of nowhere..

thanks,

g

PS: In an effort to be nicer to the neighbors i picked up a set of quiet baffles from Vance & Hines. they look pretty restrictive to me.. they are actually solid at the end with holes drilled around the outside. i don't want to put them on if they totally restrict the bike. anyone know?

springer- · 03-18-2005, 10:22 PM

A lot of people run compression releases that don't even need them. At 11:1 you are on the edge. But if your bike starts and runs fine, you should be OK. Worst case, you might someday need a hill to start it to get home but I dought that the starter would outright fail with no prior signs.

You could install compression releases with the heads on the bike. The alignment tool is bolted to the top of the head, with the rocker covers removed. The process then drills and spot faces the hole with a single "drill" bit. Then you can tap the hole and clean all the aluminum chips out of the threads. The very last drill is a small (only about 1/16") drill bit that breaks threw the combustion chamber. Such a small hole would only drop a few small aluminum chips that would easily be digestable by the motor.

If it were my bike, I would take a wait and see attitude. And look for any signs of failure BEFORE it strands you.

Good luck, Sounds like a nice ride

csoday · 03-19-2005, 12:09 AM

I would recommend comp releases on 10.5-1 or over. I would also pull the heads.

springer- · 03-19-2005, 12:27 AM

Quote:

Originally Posted by csoday

I would recommend comp releases on 10.5-1 or over. I would also pull the heads.

I'm with him, I would pull the heads too

Jeff S. · 03-19-2005, 01:16 AM

You can pull the tank and the top and lower rocker boxes and you can get it done on some bikes, and using some grease on the end of the 1/16 inch drill, ( I like to go slightly larger ) you can stop 99% or more of the contamination from getting in the cylinder, however I prefer them off the bike. I'll go you one better. You pull the heads and bring them to me on my day off and I will cut the compression release holes for you for free, but we have to set this up so I can bring home a tool. Email me if your interested. I am 55 miles East of you. Hows that for board co-operation? My theroy on compression releases, why not? At any compression. They don't hurt anything, and reduce wear and tear on your starter and battery.

GRock · 03-19-2005, 12:27 PM

I believe that SPYKE makes a new gadget that screws right into the existing plug hole and the plug screws into the gadget. No extra drilling or head removal required. Not sure if Twinkie, EVO or both, but check it out.

MilesToGo · 03-19-2005, 12:39 PM

Quote:

Originally Posted by GRock

I believe that SPYKE makes a new gadget that screws right into the existing plug hole and the plug screws into the gadget. No extra drilling or head removal required. Not sure if Twinkie, EVO or both, but check it out.

http://www.wildwestcc.com/100248.html

disco · 03-19-2005, 07:27 PM

Quick question... I've seen a few bikes with comp release (blue button)
How are they operated? Do you push them down or pull them up to start?

Disco

hdmarsh77 · 03-19-2005, 08:23 PM

Quote:

Originally Posted by disco

Quick question... I've seen a few bikes with comp release (blue button)
How are they operated? Do you push them down or pull them up to start?

Disco

Push them in to start. They pop out automaticaly when started.

gerry81611 · 03-20-2005, 01:31 PM

Thanks for the input guys, and thanks for the offer Jeff!

Pulling the heads is still a little ambitious for me, but not out of the question..

For now I am going to ride a bit more and watch how the bike starts hot and cold.

I found a reputable shop in the east bay that will pull the heads and drill the compression releases for about $600 including all parts. Thats less than half of what the stealer quoted, and better than the 20 hours i bet it will take me to pull and replace the heads since it would be my first time doing it. The shop has their own dyno and machine shop, so they don't send that stuff out.

Thanks for all the help!

g

springer- · 03-20-2005, 02:37 PM

$600.00 is a lot for compression releases. We install compression releases with polished buttons for $140. That includes the compression releases !! Can't be more than 4 hours labor to R&R the heads. Then add the cost of a top end gasket set. 600 sounds expensive to me. I'd consider Jeff's offer. IMHO

LAF · 03-20-2005, 02:55 PM

Quote:

Originally Posted by springer-

$600.00 is a lot for compression releases. We install compression releases with polished buttons for $140. That includes the compression releases !! Can't be more than 4 hours labor to R&R the heads. Then add the cost of a top end gasket set. 600 sounds expensive to me. I'd consider Jeff's offer. IMHO

You can say that again..................

nvsteve · 03-20-2005, 03:30 PM

Quote PS: In an effort to be nicer to the neighbors i picked up a set of quiet baffles from Vance & Hines. they look pretty restrictive to me.. they are actually solid at the end with holes drilled around the outside. i don't want to put them on if they totally restrict the bike. anyone know?Quote

When my bike only had a cam I tried the quiet baffles. They were somewhat
quieter at idle and lower rpms. When I got on the gas the difference in
sound wasn't that much different. I did not have to re-map and the bike ran
good.
Now the bike is 95", extensive head and intake work. I had the stock baffles
in for mapping mainly because I would have had to drill a hole in the baffles
for the oxygen sensor. Then I tried the "quiets" again. The engine was not
nearly as smooth. Plugs showed very rich condition. Went back to stock.
A word of caution: If you put the quiet baffles in they are a real *****
to remove as the packing will bunch up.

GRock · 03-20-2005, 03:35 PM

Gerry,

Are you telling me that the dealer is looking for over $1200 to R&R heads, and drill and install comp releases?????? That's stretching it even for them!! Wow! The floggings just keep on coming, don't they?? Incredible! Jeff S. makes a very generous offer.

springer- · 03-20-2005, 04:35 PM

Quote:

Originally Posted by GRock

Gerry,

Are you telling me that the dealer is looking for over $1200 to R&R heads, and drill and install comp releases?????? That's stretching it even for them!! Wow! The floggings just keep on coming, don't they?? Incredible! Jeff S. makes a very generous offer.

I was thinking ...
$199 for round trip airfare
$200 for labor
$140 to bring and install them
Pick me up at the airport, I'm going on a paid vacation !!!

j/k
Other than the fact that I won't get on a plane, I could fly there and still be cheaper !!