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How high should I go on the CR?
Valve to piston relief spec's ?
- Thread starter OLD H2S
- Start date
16:1
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Cool beans, I'm on it..
I was only joking, I only know one person that is crazy enough to actually do that.
Aint nothing e85 wont fix
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No E85.. but I do need to know what to shoot for. The '96 has no knock sensors like my Terminators did and when they knock it is supposed to be so quiet you can not hear it, or maybe the blower is so loud you did not know?
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Got out the Auto Math book and ran the numbers and the answer looks more in line with expectations. I am using -3cc for the valve reliefs and 40cc for the head chambers after decking and am getting 13.4:1 CR.
What pistons are you going with?
13.4:1 pump gas with cams wont be a problem once tuned. If you port the heads, keep the ports rough. A small exhaust valve like npi heads normally increases the need for an earlier exhaust opening, but whats normal? Long rod, long stroke, tiny bore improves combustion efficiency add in 2v heads and a long list of other qualities, these modulars really love compression.
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I was going to get ModMax cast flat top, come all ready coated sides and tops, just have to notch them. Cam is a bullet stage one from MHS
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Test of expansion on heated parts:
I took an old cast Mahle piston and a SVT rod and put them in an ice bath for a while and then measured the length on a surface plate. I put them in the oven at 450 F for 30 minutes and measured them after. The piston was .010" longer and the rod was .020 longer. I took measurements as they cooled down by using an infrared thermometer but it did not like the shiney surface of the rod and I was getting bad readings off of it compared to the piston. At a more normal operating temp for the rod of 300 F it was .010 longer and the piston did not drop down much until is was below 200 F. The rod numbers seem good and normal for the standard of .002 per inch of length and the high temp I took it to but the piston runs at 550 F at the top and much cooler at the bottom because of the contact with the cylinder wall and the oil bath the inside takes sucking heat away fast. Can you think of a way to test the pistons expansion that would be more accurate?
I took an old cast Mahle piston and a SVT rod and put them in an ice bath for a while and then measured the length on a surface plate. I put them in the oven at 450 F for 30 minutes and measured them after. The piston was .010" longer and the rod was .020 longer. I took measurements as they cooled down by using an infrared thermometer but it did not like the shiney surface of the rod and I was getting bad readings off of it compared to the piston. At a more normal operating temp for the rod of 300 F it was .010 longer and the piston did not drop down much until is was below 200 F. The rod numbers seem good and normal for the standard of .002 per inch of length and the high temp I took it to but the piston runs at 550 F at the top and much cooler at the bottom because of the contact with the cylinder wall and the oil bath the inside takes sucking heat away fast. Can you think of a way to test the pistons expansion that would be more accurate?
I have tried to measure the piston after being heated 600°....the piston cools to fast! Unbelievable how quick it cools! Makes my measurements debunked!
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Sorry for the delay, medical problems. Here is a pic of the pistons.
I found some 3" and 4" micrometers on Swisslink.com for 20.00 each, top quality form 1984 made in czechoslovakia, look at the size of those anvil handles!
Next up is some insite on how to make an exact copy of a cavity when making a EDM electrode, why? because this is how to grind out a intake port on a head and make a copy to stick in the next port to make sure the port is the same size, fast, cheap, makes a positive form of the port for inspection, measuring and copying on a Deckel 3D panograph. This is fixturing product called Jet Sett from Rio Grande,https://www.riogrande.com/Search/jet-sett
You heat it up in warm water till it is soft a mash it into the port wait for it to cool down and pull out a positive casting of the shape to shove into the next port to see how much more to remove to make it fit. I would put it in a baggie to keep it from sticking and put a handle in it. I use it to make perfect fixtures to hold odd shaped parts so the can be machined. When done just reheat and use again, big chunks take awhile to heat all the way though.
Genius!
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I got a set of PI heads, Windsor type, part number RF-XL3E-6090-C20D for the the passenger side, drivers side the number should be 6080? but it is different and hard to read. They are coming up as F-150 5.4 heads, the kid I got them from had a mess on his hands and is bewildered thinking his pile of engine junk is a 4.6. I am missing the valve covers from him so I have to play nice. The cam journals have some damage but that will be a later post, If I get them cleaned up this week end in the cold weather. Here are some pics of the exhaust valve and seat that are eroded, the contact area on the valve is too wide and it traps junk when it closes and the seat and the valve face get damaged, the wide seat transfers heat better but traps junk. Look at the intake seat and it looks dirty but shiny.
This is going to need a new valve and the seat recut, so the fun is just starting, stay tuned...
Typical exhaust valve seat condition. Im gonna say thats the worst ive seen. Once the garbage sets on and prevents valve from seating, the torching begins. Routine oil change negligence.
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Cleaned the heads, pulled out the little plug in the bottom of the head..
...Then this multi colored goo,
Looks like this side was running lean,plugs were white on the tip.
This is awesome info....keep it coming!
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Waiting on parts, nobody likes to tell you something is not in stock, they all want the sale and cash flow. I have been sweating the valve guide removal a job I have screwed up in the past. I got a pilot drill that the pilot was under 7mm to cut down on gouging but the drill is too short overall to go all the way through and the stock guides are harder than I thought. I was hacking together a sine plate to support the heads, most are too small and they are pricey. I was trying to make one the size of the head but that is a big sine plate. I got a straight blank for my impact driver and cut it down on the lathe to make a 7mm pilot to keep it going through without gouging the wall of the hole. I was worried about the impact cracking the head. I heated the head to 300f in the oven and BANG ZOOM all the guides came out in 5 seconds each.
You da man! Nice turn work by the way! Gonna install a set of bronze guides? 8mm I.d.? 1.900" valve?
