Full Answer
What base gaskets for late Evo?
If so or you decide to take the barrels off then use the Harely base gaskets for late EVO's. Those gaskets are like using fly paper as they are sticky on both sides and until you pull the jugs loose again they will not leak.
What size head gasket do I need for a Harley Davidson?
When the engine is assembled, use one of the .030 inch thickness head gaskets instead of the normal .040 or .060 inch gaskets. This will give the engine a mechanical compression ratio of almost 9.5:1. This is considered the minimum compression ratio needed to make serious power from a Harley-Davidson engine.
What size head gasket do I need for a bolt in Cam?
For street engines with bolt-in cams, limit the milling to. 050 inches. When the engine is assembled, use one of the. 030 inch thickness head gaskets instead of the normal. 040 or 060 inch gaskets. This will give the engine a mechanical compression ratio of almost 9. 5:1.
Can you fix a leaking head gasket without a base gasket?
Also if you have had leaking base gaskets on the left front of cyls., there is a "pigtail" fix available, but not really necessary with James or Comotec gaskets. I do not know anyone that has replaced head gaskets without doing base gaskets also. Be sure to find out why the head gasket sprung a leak.
How thick should my head gasket be?
Head Gasket should be . 030" thick. Compression will be increased but no problem on iron heads. Compression will be in the 13:1 range using 3400 heads.
How do I know what size head gasket to get?
When selecting a gasket for your engine, you can either select the same bore size as your block or one service size (typically 0.5mm / 0.020") larger. If you ask for a second opinion, you may hear an expert or enthusiast recommend up to . 060" larger.
Is a thinner head gasket better?
Head gasket thickness will impact Compression Ratio. Changing gasket thickness can be used to fine-tune compression. However, the gasket's thickness will also affect its ability to seal the combustion chamber and oil and coolant passages. For most engines, we recommend the OEM gasket thickness.
Is a thicker head gasket better?
Some manufacturers recommend using the thinnest gasket possible to increase the compression ratio by lowering the cylinder volume. Depending on how much of the surface is removed, you may need a thicker head gasket to preserve the piston-to-deck clearance to ensure the pistons don't hit the head under a heavy pull.
Will a thicker head gasket lower compression?
A thicker gasket will reduce the compression ratio by a small fraction, probably only by . 1 or . 2. This is by far the easiest method of reducing compression but the risk is gasket failure and the gains in lower compression are minimal.
Why are head gaskets different thickness?
The thickness of the gasket, which separates the block from the cylinder head, plays a role in the compression ratio by altering the volume of the cylinder. Creating more pressure means the piston pushes harder and faster, making more horsepower and torque.
Can you put 2 head gaskets?
it is better to use one. two won't harm anything but sometimes having two will cause one gasket to squeeze outward and create a leak. also, two will raise the head slightly causing slight compression drop.
What is the thinnest head gasket?
Registered. Around . 040 is about the thinnest composition gasket as far as I know, surface the heads if it's that important.
What is the best head gasket?
The Steel Seal Blown Head Gasket Fix Repair Sealer is our top pick for the best overall permanent head gasket sealer. It works well on older and new vehicles and is suitable for cars, vans, SUVs, and trucks. If your budget is a little tight and you still need a professional-grade sealer, check out the K-Seal ST5516 HD.
Are copper head gaskets better?
Malleable: Copper is stronger than any composite head gasket yet still malleable so it conforms to the sealing surfaces. This strength-malleability combination is, more than any other attribute, the 'selling point' of copper as a head gasket material over other materials.
What happens if compression ratio is too high?
Higher compression ratios can make gasoline (petrol) engines subject to engine knocking (also known as "detonation", "pre-ignition" or "pinging") if lower octane-rated fuel is used. This can reduce efficiency or damage the engine if knock sensors are not present to modify the ignition timing.
What happens if you put a 88-03 piston in a 04+?
If you put an 88-03 style piston into an 04+ bike, the skirt on the side will smack into the oil squirter and break it off.# N#It's a full tear down to fix. 7)
When did piston pin clips change color?
The piston pin clips used on all Evolution models changed in color from silver to bronze during the 1992 season .#N#This was a manufacturing request for visual verification of installation during assembly.#N#The part number was changed from 22589-83 to 22589-83A. The changed occurred in production approximately in September of 1991. 10)
How to test a bike cylinder?
Lift the bike or block the rear wheel off the ground. Put the transmission in 4th gear. Place your thumb over the spark plug hole of the cylinder you intend to test. Have a helper rotate the rear wheel as you feel for pressure on your thumb.
What does it mean when your piston rings are low?
A low reading on either cylinder indicates a possible valve or piston ring issue. To determine which, pour about 1/2 teaspoon of oil into that cylinder through the spark plug hole. Then repeat the compression test. If the reading returns to normal the rings may be defective.
What is a cylinder pressure test?
Cylinder Pressure Test. It is important to make a check of your cylinder pressure (aka engine compression) as soon as you obtain your bike and , at least, on an annual basis thereafter. This is a great reference value to determine if the pistons, rings, cams, lifters, pushrods and valves are all functioning correctly together.
travhous New Member
1987 flh 1340 stock, I have blown head gasket, i can see oil and there is a slight tick where you can feel air excaping between the head and cylinder. How difficult of a replacment is this and what extra parts would be good to replace at the time. I have never worked on a harley engine, but worked and rebuilt a hand full of chevy V8.
Jack Klarich Guest
Buy a Manual Evo Heads are tricky require precise torque Look for cosmetic or Bartells metal base and head gaskets follow instructions and use spray copper coat should do the trick
glider Veteran Member
If you work on Chevys, you can probably do the job with little problems. Get the manual for the torque values and follow them. Use a quality head gasket like James gaskets and a few others.
TQuentin1 Well-Known Member Staff Member Moderator
1987 flh 1340 stock, I have blown head gasket, i can see oil and there is a slight tick where you can feel air excaping between the head and cylinder. How difficult of a replacment is this and what extra parts would be good to replace at the time. I have never worked on a harley engine, but worked and rebuilt a hand full of chevy V8.
Breeze3at Experienced Member
Travhous; Yea, everything TQuentin said above. Plus the sevice manual says you are supposed to use new cyl. studs because of stretch and it changes the torque settings. I know someone who has done it without replacing them with no ill effects.
Fossil Active Member
Be sure to find out why the head gasket sprung a leak. Look closely at the base gasket on the rear jug to see if it is leaking. If so or you decide to take the barrels off then use the Harely base gaskets for late EVO's.
When did the Sportster carburetor upgrade?
In 1988 , the stock Sportster carburetor was upgraded to a Keihin 40mm, slide-type, constant-velocity model. It was quickly discovered that the lack of an accelerator pump was a shortcoming.
What is the casting on a throttle body?
1) The throttle body casting contains an integral venturi and a fuel valve seat that is pressed into the body. The underside of the throttle body contains a boss. The main jet screws into the boss and holds the bleed tube in place. 2) Operation: Fuel from the gas tank passes through the fuel valve, onto float chamber.
What carburetor did the Ironhead use?
From 1986-1987, the stock Sportster carburetor was a Keihin 34mm, fixed-venturi “butterfly” model, as used on the Ironhead models from 1979 onward (BT models still used the 38mm version). Contrary to popular folklore, all Keihin non-CV carbs did come with accelerator pumps.