Adjustable fuel pressure reg to solve exhaust mainfold warping?
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Adjustable fuel pressure reg to solve exhaust mainfold warping?
I have heard that a lean condition (EFI)causes/contributes to the famous Ford exhaust mainfold warping . Will increasing fuel pressure via an adjustible regulator help? If so what brand and /or part number? Me and my friend between us have 3 Ford efi 460's with this problem. All are mid 90's 460 efi trucks.
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From: iowa
No it won't becase the computor will read the richer condition, and just reduce the injector dwell time to lean it back out. It's in the programing bumping the fuel preasure up will mainly just cause a rich idle condition, and usually poor running unless you reprogram the ecm.
You would get more results putting a resistor inline for the temp sensor so the computor thinks the engine is always colder than it is, and tries to richen it up. I don't recommend it but that would actually have more affect.
Now you could bump the fuel preasure up some to help out with top end performance but thats all it will accomplish except to maybe eat more fuel, like these engines need any help in that area.
You would get more results putting a resistor inline for the temp sensor so the computor thinks the engine is always colder than it is, and tries to richen it up. I don't recommend it but that would actually have more affect.
Now you could bump the fuel preasure up some to help out with top end performance but thats all it will accomplish except to maybe eat more fuel, like these engines need any help in that area.
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So, Would lowering the operating temp of the engine by installing a cooler thermostat (160 or so) cause the engine to run a tad richer and possibly help with the manifold problem? Is there any help for the warped manifold syndrome? Don't say headers because we've tried them and have had the one set replaced/repaired 4 times by L&L (Tubes burning out)
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From: iowa
Running a cooler thermostat usually helps with the power, but almost always hurts fuel economy (what there is for fuel economy with a 460 to start with). And no I don't actually believe it will help with the warped manifold problems, 460 manifolds have been known for cracking long before fuel injection, personally and this is just that an opinion, the manifold problem is a design flaw having to do with the fact that all the bolts on a 460 are in a line instead of staggered. FI may agrevate the problem but I don't think it's the main cause. The best way I have seen to prevent it is don't use a gasket. Make sure the manifold is machined perfectly flat, and the exhaust surface on the head is perfectly flat, then just mat them up without a gasket, or if you really must a VERY thin layer of red silicon, and properly torque the bolts. Once again this is just my opinion, and should not be construed as fact.
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From: Fort Worth,Texas
I think it is a desing flaw in the exaust manafold. All the the wxaust must flow to the back in a single pasage. This increases the heat load on the back of the manafold hense all the cracked manafolds and broken bolts. This is especialey true on the pasenger side in the back. Outher makes and styles the exaust manafold lookes and workes like headers with individual runers taking the exaust gases to a collector.
I would just dump the stock exaust manafolds and get a set of headers appropreate for what you are doing.
Bill
I would just dump the stock exaust manafolds and get a set of headers appropreate for what you are doing.
Bill
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what i have heard is that if you make the bolt holes on the exhaust manifoldsmore oval shaped to allow for the expansion of the bolts you will cure the broken bolt problem , i did this with a hard bit drill ,you could use carbide tips,or take it to a machine shop..also i would recommend new grade 8 bolts i ordered a few from ford,very pricey like $12.00 a bolt ,clean the head threads with a 3/8 tap ,goop lots of antiseize,,yes headers are better,but manifolds are quieter,,plus i put true duals with high flow dynomax mufflers,,some day i'll put headers,,plus l don't torque the bolts down too hard ,i will loosen them up and retorque maybe in a year or so to prevent them seizing up,never use hardware bolts
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From: Fort Worth,Texas
Mustangman,
I must be in the wrong bisness I should be reselling hardware. I don't have the receipt but I think I paid about 10.00 each less at Home Depo. Grade 8 stainless is Grade 8 stainless. I would also look at ARP.
Sorry but I had to chuckle at the comment "headers are better,but manifolds are quieter" Then you talk about "high flow dynomax mufflers" Don't worry you problem won't be able to hear the headers over the high flow dynomax mufflers. I think you could by the ceramic coated ones and wrap them if noise is a problem. BY the way if you have a cross pipe on your duels it will help low end torque.
Bill
I must be in the wrong bisness I should be reselling hardware. I don't have the receipt but I think I paid about 10.00 each less at Home Depo. Grade 8 stainless is Grade 8 stainless. I would also look at ARP.
Sorry but I had to chuckle at the comment "headers are better,but manifolds are quieter" Then you talk about "high flow dynomax mufflers" Don't worry you problem won't be able to hear the headers over the high flow dynomax mufflers. I think you could by the ceramic coated ones and wrap them if noise is a problem. BY the way if you have a cross pipe on your duels it will help low end torque.
Bill
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The guys above are giving you some sound advise. This is a big topic on the RV forums. The answer is headers but dont accept anything with less than a 3/8 flange, and even they will warp. Half inch is better and if you can afford it Banks 5/8 flange stainless is case closed end of problem. If you pull off your existing manifold and put it on a perfectly flat surface like a plate of glass, you should not be able to insert a feeler gauge larger than .010 anywhere around the circumference. If you can it's warped and will always leak no matter what you do. If you plane it the problem just comes back. Ford has new manifolds that they say dont warp but the RV guys say they still do. I put the Banks on mine and that solved it.
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Originally Posted by WILDEBILL308
Mustangman,
I must be in the wrong bisness I should be reselling hardware. I don't have the receipt but I think I paid about 10.00 each less at Home Depo. Grade 8 stainless is Grade 8 stainless. I would also look at ARP.
Sorry but I had to chuckle at the comment "headers are better,but manifolds are quieter" Then you talk about "high flow dynomax mufflers" Don't worry you problem won't be able to hear the headers over the high flow dynomax mufflers. I think you could by the ceramic coated ones and wrap them if noise is a problem. BY the way if you have a cross pipe on your duels it will help low end torque.
Bill
I must be in the wrong bisness I should be reselling hardware. I don't have the receipt but I think I paid about 10.00 each less at Home Depo. Grade 8 stainless is Grade 8 stainless. I would also look at ARP.
Sorry but I had to chuckle at the comment "headers are better,but manifolds are quieter" Then you talk about "high flow dynomax mufflers" Don't worry you problem won't be able to hear the headers over the high flow dynomax mufflers. I think you could by the ceramic coated ones and wrap them if noise is a problem. BY the way if you have a cross pipe on your duels it will help low end torque.
Bill
Last edited by mustangman; Jun 2, 2006 at 10:26 AM.
Hotshot
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From: iowa
The reason you can't find grade 8 stainless bolts is because they don't make such a critter. and you can't mix stainless and titanium so that is hearsay besides there is no way ford would ever pay the cost of titanium bolts, go look at the price, heck $12 for a bolt that size in titanium would be a killer deal, try about $50 each.
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Originally Posted by monsterbaby
The reason you can't find grade 8 stainless bolts is because they don't make such a critter. and you can't mix stainless and titanium so that is hearsay besides there is no way ford would ever pay the cost of titanium bolts, go look at the price, heck $12 for a bolt that size in titanium would be a killer deal, try about $50 each.
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From: Fort Worth,Texas
I have to admit I fell into the trap of repeating what I was reading and not typing what I know.
That was stupid of me and I apoligise.
1. Stainless can't be heat treated so it can't be a "grade8" that speck describes the leavel of heat treat for strenth. Example Grade 5, 1/4 to 3/4 diameter bolt should give you a 85,000(psi) proof load 92,000 (psi)minimum yield strength and 120,000 (psi) minimum tensile strength.
GRADE 8 120,000 (psi) Proof load,130,000 (psi) Minimum yield and 150,000 (psi) Minimum tensile strength.
Stainless can varey based on the alloy but the stronger alloys are basicley interchangable with grade 8.
I would go to Sumit racing and get
SUMIT PART NUMBER ARP-400-1202
Extra-high strength and corrosion resistance.
ARP stainless steel header bolts are 15 percent stronger than Grade 8 steel. These 12-point bolts have a compact head that will allow a socket to fit into those tight, tricky spaces next to the headers. These bolts are both highly corrosion-resistant and heat-resistant. They have a polished finish and come in 12-point and hex-style heads. Washers are included.
$16.88 Sold as a set of 16
That is the point I was making that figures out to $1.055 per bolt including the washer.
I would recomend the Thorley try y headers for that aplication. I would not put the stock manafoldes back on you will have problems later. They will warp and crack eaven with stainless bolts. You will also have less performance.
Bill
That was stupid of me and I apoligise.
1. Stainless can't be heat treated so it can't be a "grade8" that speck describes the leavel of heat treat for strenth. Example Grade 5, 1/4 to 3/4 diameter bolt should give you a 85,000(psi) proof load 92,000 (psi)minimum yield strength and 120,000 (psi) minimum tensile strength.
GRADE 8 120,000 (psi) Proof load,130,000 (psi) Minimum yield and 150,000 (psi) Minimum tensile strength.
Stainless can varey based on the alloy but the stronger alloys are basicley interchangable with grade 8.
I would go to Sumit racing and get
SUMIT PART NUMBER ARP-400-1202
Extra-high strength and corrosion resistance.
ARP stainless steel header bolts are 15 percent stronger than Grade 8 steel. These 12-point bolts have a compact head that will allow a socket to fit into those tight, tricky spaces next to the headers. These bolts are both highly corrosion-resistant and heat-resistant. They have a polished finish and come in 12-point and hex-style heads. Washers are included.
$16.88 Sold as a set of 16
That is the point I was making that figures out to $1.055 per bolt including the washer.
I would recomend the Thorley try y headers for that aplication. I would not put the stock manafoldes back on you will have problems later. They will warp and crack eaven with stainless bolts. You will also have less performance.
Bill
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