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Discussion in 'PT Cruiser' started by Fullpass, Jan 25, 2017.
Just some before pics of the original head and valves, everything is marked to be placed back in original location..So much for getting this job done in a week...but I'm learning a lot...well worth the knowledge...will be looking for loaded turbo convertible PT...to fix...half to be some out there...have one...I might come out and get it...
yes have the valve stem seals, came with the Fel - Pro kit, also taped to loosen keepers, non where stuck...That OTC tool is great for the overhead valve springs..Just waiting for the Gum 2 + 2 ...want to see how well everything will clean up before taking the brass wheel to valves and ports.
So, given you have a couple days to wait until your Gum 2 + 2 shows up, want to add a little efficiency to the cylinders? It's good for a few hp and torque, and a little increase in rpm mileage (like the same at 85-90mph as you get at 65-70?).
See all those sharp edges around the valves and the flat of the head surface? Those areas are known for collecting gasoline and detonating, pinging (forces your timing to back off), and prevents flow from exploding across the whole surface. See how those flat spots are clean and the valve pocket is dirty? what do you think happens when the sharp edges are removed, preventing the flame from curling at those sharp edges and the flame travels into those clean areas to burn faster, prior to the piston dropping and the then the flame burning the fuel/air that is in those clean areas? Answer is, the bigger explosion you have at a higher compression, the more power you produce.
simple solution and only takes a couple hours of work. Grind, cut, or round file those sharp edges so they don't exist, so the flame travels over them instead of curling back into the already burned fuel/air area already. Sorry, I don't have a good picture to show you, but, you can see your head gasket ring on the surface of your head, just round all the sharp edges inside the combustion chamber as round as the wire on your computer mouse and you will have a noticeable difference in its production of power and efficiency. It's like running around empty and having three people in the car with you as the same, hitting hills and not having to shift or shifting later, makes a difference, and an extra 3mpg lost going 20mph faster gone. Easy to do with a simple round file, me, I like using a carbide burr cutter about the size of my pinky, rounded end and all.
Had some engine degreaser in the garage...made by Prestone..hard to wait when you have things to do...went ahead and cleaned the cylinder head up...the Prestone engine degreaser did pretty good, along with some carb cleaner I had...Going to send the Cylinder head out today local machine shop to have it decked...charging me $65...thought that was very fair. The cylinder head cleaned up pretty good, valve seats, look pretty good...will lap the valves once I get the deck back....by hand of course...In the pics below I had put the valves back in momentarily with oil, to get some oil on the guides..didn't want to leave them dry...rust. so you might see some oil in the ports.
Dana44 Nice Tip
You are right..those edges around the valve cylinder head chamber are very sharp...I can at least dull them. If you have a pic of the carbide burr cutter that you use would be great.
So far hadn't had to use the brass wire wheel, or dermal, but can touch up a few things once the cylinder head is back...guess I will use the Gum 2+ 2 on the valves...have them to do yet...or maybe I can just use the brass wheel on the bench grinder, but really everything is cleaning up pretty good with out brass brushing
Looking at the above combustion chamber photo...the lower right corner bolt holt has a oil port/chamber...I going to measure the depth of that port...to see how much the machine shop will have taken off...also had read...its important to dermal the chamber depth back for good oil flow. Oh on that note...if the new head bolts do not have exact bolt thickness..some are tapered in the middle like an hour glass factory?...that would be extreme, just pointing out the concept, but if the new bolts are straight, non tapered, the cylinder bolt hole should be widened to get the proper oil flow...Just from what I have read..I hadn't compared my new bolts to the old ones yet...so many little things can make a difference.
I like these two shapes, the one on the right is best. There is a courser cut, as in less swirls for aluminum, but have found for detail work like combustion chambers and going slower, more delicate like around valves is safer. The problem with sharp edges inside combustion chambers is, they do two things. One, collect fuel at the edge because of the shear, so they tend to heat faster than the rest of the combustion chamber and are the first to ping. Second, rounded edges allow fuel and explosions to roll over them and outward. More power and efficiency is gained by having the fuel/air explode with the piston as high as possible in the cylinder instead of having a residual burn as the piston is heading down the cylinder, so they burn cleaner, too. Any sharp edges being rounded is a plus, and the texture the burr cutters leaves is great, prevents the fuel from sticking to the surface. I have had heads I ported, combustion chamber work does the most improvement in performance and efficiency, and removing the heads after more than 100,000 miles has the combustion chambers as clean as the day they were installed (with small carbon build-up spots along the outer edges of the quench pads), whereas the carbide burr cut areas can literally be wiped clean with a rag, nothing sticks to the surface because the little cupping marks left make the flame skip off and outward, expanding the flame front instead of (in stock form) hit the sharp edge and bounce back. Oh, and my oil stays cleaner longer, too.
Dana44 ~ Question
Are you just taking the sharp edges off the flat chamber edge and the valve double arches or going all the way around the combustion chamber, as the sides between the chambers are kind of thin.
When it comes to the sides of the combustion chamber between the cylinders, I simply open them so they go straight at the sides to the gasket sealing ring. A taper here doesn't do much because the flame has already gone to the outer edge of the combustion chamber and cylinder so a return bounce is fine. This also opens up the shrouding to the valve itself a tiny bit, then round the pad quench edges, and you can even remove the ridges around the valve seats inside the combustion chamber. Just visualize every single sharp edge as flow restriction, hot spot, or flame stopping, whereas rounded allows flow to move over it, and flame travel to pass across it and outward. Any sharp edge, roll it over about the roundness as the wire on your mouse, while not much, does make a difference.
Question ~ Can you put Turbo head gaskets on non turbo models to help prevent overheating issues...more of a safety margin...more passages will be open to the cylinder head? Anyone done that...
Even if thinking of adding a turbo later or not
Will say that little car puts out a lot of heat in the car in the winter...but don't need that much...
The PT engine is not very known for overheating problems, or blown head gaskets really, it's usually a bad injector (causes a lean heat condition), cooling fan failure, and letting the fluid run low that causes problems. In fact I haven't ever had problems with having to burp the cooling system it is that good. A turbo later, unless it is the low pressure (7psi, no inner cooler and all that) is the stock engine without anything special to begin with. As far as using the head gasket, the water passages in the head gasket simply need to be drilled into the head and the block (if they aren't there) to utilize them. Yes, I always turn the heater down myself, the rest seems to hold together just fine. Oh, and one good way I have been using for literally decades is to drill a 1/16th inch hole in the face of the thermostat so you can have small air bubbles move from the head and through the thermostat while filling it initially, and whenever they are present under the thermostat itself. Never had an issue of air in the block or head ever since. In fact the last Mopar thermostat I bought had a little brass T pin in the right place for just that reason, it moved in a slightly larger hole than the brass T pin, so I just cut it off.
I like the 1/16th hole in the face of the thermostat idea...will do
Injector part numbers...brand...pressure/flow rating...maybe I can find some on eBay..that have been sonic cleaned and flow tested/matched, local dealer does not have a machine to clean..not looking to buy all new...cost, but sometimes you can find a cleaned set on the internet, shops do this as a service...I have new injector O ring seals from the Fel-Pro kit
Also I had seen the location of the radiator expansion tank in two locations.
Which location is better...updated version...might relocate mine
1. right inner fender strut tower area
2. engine fire wall
My radiator expansion tank..'05 is located on the engine fire wall, back behind the engine exhaust manifold there about on the firewall
I had seen some pictures of the expansion tank being located on the right inside upper fender towards the strut tower.
The concern...My current expansion tank location on the back firewall..The tank is lower than the radiator neck outlet tube...also the outlet coolant hose from the radiator neck flows up towards the strut tower and down to the expansion tank...just seems like a place for air to get trapped...I'm sure if all the outlet tank hose connections are tight, all is good. Coolant will flow back when radiator cools back down..
That being said, I still like the idea of having the expansion tank higher up on the strut tower...gravity certainly can't hurt to help the coolant return to the expansion tank when cooling.
Opinions...as always greatly appreciated...
My '02s have it on the fire wall and I never had a problem with them there, the hose to it seems to flow upward (for air bubbles to escape in the hose and replace with fluid.
2/15 update...picked up the original cylinder head from the machine shop....very happy with the decking job, but the cylinder head did require a full bath with dawn dish soap...several times, looked clean, but just a ton of light aluminum flake just keep coming out of the head ports. Must have washed/rinsed at least 10 times. Had placed cylinder head in a plastic been...used a rinse hose, let water gather at the bottom of been...I would dump the water out and look for any aluminum particles in the water...just a ton swirling...just repeated the process until clear. Hope to have valve in Thursday 2/16 lapped N. I did also take off the sharp edges on the cylinder chambers and ports in the cylinder head...Just with 2000 grit wet sandpaper...to take the sharpness off the edges...Oh did put oil back on valve guides after washing..prevent rust.
On a different note:
Surfometer...checks the smoothness of a finish...I don't have one...but used one before...the new decking finish is not as smooth as the original OEM CYLINDER HEAD FINISH....I can feel the finish with my finger nail on the new decking...old finish was smooth like glass...almost...But hey this machine shop dose a ton of engine work for race cars...must know what they are doing. Will post up some pics the 2/16...This engine is going together very soon..
Yeah, that's where the flat glass and 500grit/wet/dry across the face to take off the ridges is needed. Front to back, then 45 degree angles both sides works best and she will be fine. Takes about ten minutes, then rinse again. Ugggh.