FE Power Forums
FE Power Forums => FE Technical Forum => Topic started by: gregaba on February 04, 2021, 12:07:28 PM
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I would like to install knock sensors on my 428. Aluminum heads.
Anybody done this and how did you mount them and where?
Thanks
Greg
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I think that the juice isn't worth the squeeze. A knock sensor is a fussy tool that needs to know what right is to ID what wrong is.
I think staying within known spark/load/mixture tables will keep you exactly where you need to be in a modern EFI. In fact, if you weren't trying to run uber lean and therefore requiring max timing, like a modern EPA/mileage constrained car, not sure it would ever do anything anyway
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Ok
Thanks
I was worried a little about detonation and thought I could use it to retard my timing in a bind.
Greg
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As Ross said, It takes a lot of work to get a knock sensor right. At Ford, we had to dyno test extensively to find the sweet spot. You look at the signal on an oscilloscope for sensors in different places on the engine.
Engines make a lot of mechanical noise. Changing anything on the engine (intake, cam, stroke, piston design, even accessories) changes what the sensor sees. There is usually a spot on a head or the intake where the knock noise will really come through while the normal mechanical noise doesn't. It's a black art.
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Well I don't have the resources that Ford has or the knowledge to set one up right so this will just be one of my dumb moments.
Greg
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A knock sensor is a fussy tool that needs to know what right is to ID what wrong is.
Ross is right. Manufacturers have sophisticated multi-million dollar equipment/software to determine where to place knock sensors, and then they have to be 'taught' what to listen for with more sophisticated software. Trying to do that in an old engine is next to impossible without the same research, computer aids and software to run it. If it were possible to use a knock sensor in an old engine to just trigger a light, then it would probably be set off by a multitude of noises. I'm also not aware of any way to 'filter' the noises that a sensor picks up, so adapting a stand-alone system to a non-computer controlled car would be near impossible.
Honestly, the best knock sensor for old engines is learning to read plugs. Looking for signs of 'peppering' on the plugs will indicate you are either running too lean, or have to much compression for the fuel, or that the timing curve is too fast or total too high for the load.
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I was thinking that with a sensor I could get by with running 100 instead of 110.
I guess I will just have to do it the old fashioned way.
Its just that I am a little lazy and all ways looking for the easy way.
Greg
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As Ross said, It takes a lot of work to get a knock sensor right. At Ford, we had to dyno test extensively to find the sweet spot. You look at the signal on an oscilloscope for sensors in different places on the engine.
Engines make a lot of mechanical noise. Changing anything on the engine (intake, cam, stroke, piston design, even accessories) changes what the sensor sees. There is usually a spot on a head or the intake where the knock noise will really come through while the normal mechanical noise doesn't. It's a black art.
Well said. NVH analysis is insane.
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I was thinking that with a sensor I could get by with running 100 instead of 110.
I guess I will just have to do it the old fashioned way.
Its just that I am a little lazy and all ways looking for the easy way.
Greg
I am not sure it's going to be that much work, were you asking about tuning an EFI system? Pretty much everything under the sun has been done, if you have the mixture right, we can tell you a timing curve, and you may not even need to run 100. A lot of us are making a lot of power without race gas.
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I had my machine work done in Texas [block blueprinted] and he told me I should run 110.
I had the block decked to 10.150, cam and mains aligned bored, crank assembly balanced. and lifters sleeved. Block was decked for MLS gaskets.
TFS heads version 3.
Autotec pistons -flat top with 5.000cc, bore of 4.165, comp. dist is 1.675 with the small ring pack.
Brent told me I would be around 11-4 compression ratio max.
I need to get the short block together to check how far down the bore the pistons are to figure it out for sure.
I will be running all the FE Power front parts and the intake adapter with a TFS 351C single plane intake.
I am deciding between a megasquirt 3 or a Holly EFI. I haven't ordered one yet.
For the first 6 months I am going to run the Ford D cam and if I don't like it will change to a custom solid roller.
Going in a 63 Galaxie 2 door sedan that was a race car from birth. Haven't weighed it yet but there is no heater, sound deaden er etc in the car.
I would like to run pump premium in it but don't think it would work.
As far as the ignition goes I haven't decided yet. depends on what EFI system I go with.
Just a weekend driver I want to have some fun with.
Greg
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I would be very surprised that you need to run 110 octane fuel with your combination.
11.4 CR with a tight quench distance (0.050") and the reasonably decent TFS combustion chamber
along with a reasonably big camshaft should run quite well on 94 octane.
Not sure what pump fuel you have - perhaps some octane booster in a tank of fuel also.
Brent may have some comments on octane requirement here.
He has built a few TFS headed engines and would have a good idea regarding detonation with these heads.
Cool build. Are you going to dyno the build?
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I was thinking 110 would be a bit high for my combo.
The best I can do here is 91 octane so I contacted Rocket fuel and will be buying a 55 gallon drum of their fuel and mixing it with our sorry gas and see where I come out on it.
I was hoping the TFS heads would let me get by on at least 100 but if I can go lower safely then I will.
I will be assembling the short block in a couple of weeks and then when the heads come in I can finish it up.
It will only see a few thousand miles a year so the gas expense won't be to bad hopefully.
Greg
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I would like to install knock sensors on my 428. Aluminum heads.
Anybody done this and how did you mount them and where?
Thanks
Greg
The typical place is just below deck and center of the head. Compared to what manufacturers do there is not an ideal place on the FE. With enough room for 3" header to block gap you could probably get away with taking a discrete plug of cast iron to the block between 2&3 and or 6&7 and tapping it for one. Just needs to be as close to the cylinder head as possible for it to read and have time to adjust.
As far as aftermarket systems I am clueless. Been thinking about adding one but have not done the research to know what fits my needs. Adjusting timing between 400 and 4000 feet above sea level gets bothersome after a while. Especially in the summer when ambient temperatures make it temperamental. Cruising is 12.6 up high vs 13.6 down low so I don't bother with jetting. Millions of regular folks and truckers made roadside adjustments in days past, now people think your broke down.
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So I am guessing that you are using a .050 Cometic, I get the same numbers as Brent
I'd say if running a common hyd roller cam with about 298 adv on the intake side, spread the centers to 112-114 and put it on 108, likely 114, the combination of the good chamber, tight quench, and not a ton of overlap will keep things happy on pump gas. It's a big cam for a 428, but spreading them will tone it down to let the O2 sensor do it's thing and have a by product benefit of less "5th cycle" cylinder fill as it comes up on peaks
I doubt it would even have a funky timing curve or anything really that weird. The rate of advance depends on the rest of the combo, but it won't need a lot of total or initial, and EFI allows you to crank with low initial and immediately kick in. I'd prefer to see a 1/4 to 1/2 point less, and maybe a bit less cam depending on combo, but I don't think you'd have a problem if the cam choice matches your setup
I am not a "kill the compression with DCR guy" but the heads and flat top bought you a clean chamber which should work well. Typically though I push decisions to be more (very simplified order) cubes, induction, cam for RPM range based on the first two, then pick compression to support. This is sort of backing into it, but sometimes we do what we have to do
ON EDIT: I was messaged that this was the D cam build, I forgot about your plans. I am not by any means trying to revive the old argument we had, so please don't let me be the cause of a banter, but that much overlap, even though the DCR may drop, will fight the O2 sensor and create a situation that, if you can get to the peak RPM, will fill the cylinder to a point it likely will need to be spiked with some kind of octane booster. How much depends on what you can do with the EFI for tuning and the conditions that you are experiencing at WOT. As much as I would love to hear a D cam in a stout engine, an understatement is that it's really a tough cam for the parts you are using, Additionally, as said earlier, but more so, I would expect the knock sensor to be a no-go with a solid lifter cam, they are noisy and slappy. May not be the same frequency as detonation, but it's more noise the sensor would need to overcome or blank out
If you go this route, be sure to have the EFI tuner go open loop at any significant throttle setting, in fact, it may need it all the time, and pull timing out at RPM and load until you can sneak up on rate and total
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I had my machine work done in Texas [block blueprinted] and he told me I should run 110.
I had the block decked to 10.150, cam and mains aligned bored, crank assembly balanced. and lifters sleeved. Block was decked for MLS gaskets.
TFS heads version 3.
Autotec pistons -flat top with 5.000cc, bore of 4.165, comp. dist is 1.675 with the small ring pack.
Brent told me I would be around 11-4 compression ratio max.
I need to get the short block together to check how far down the bore the pistons are to figure it out for sure.
I will be running all the FE Power front parts and the intake adapter with a TFS 351C single plane intake.
I am deciding between a megasquirt 3 or a Holly EFI. I haven't ordered one yet.
For the first 6 months I am going to run the Ford D cam and if I don't like it will change to a custom solid roller.
Going in a 63 Galaxie 2 door sedan that was a race car from birth. Haven't weighed it yet but there is no heater, sound deaden er etc in the car.
I would like to run pump premium in it but don't think it would work.
As far as the ignition goes I haven't decided yet. depends on what EFI system I go with.
Just a weekend driver I want to have some fun with.
Greg
You don't need straight 110 but I wouldn't chance it on pump gas either, *especially* on 91 octane. Mixing is the correct solution and you can mix something like 110 with 91 (50/50) and be ok. I've had good luck with VP or Sunoco fuels. You can try some VP C12 or Sunoco 110.
If it were 11:1 and 93 octane was available, I'd go for that with the correct combination of parts.
The "D" cam will be nostalgic for sure, but it will be down 20-30 hp to a modern camshaft that's smaller. If I remember correctly, it has 100° of overlap (or maybe a hair more). Jay's first camshaft in his cylinder head test mule engine had 102° and it was just pushing power out the exhaust.
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Serious question, what about running something like Octanium? I've read up quite a bit on this, at first thinking it was another "snake oil" BS octane booster, but apparently it's legitimate. Seems if you're on the edge of being able to run 91oct, this could get you in a range that would work? Certainly easier to use than acquiring/storing/transporting/mixing race gas
https://vpracingfuels.com/product/octanium/?c=207
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The "D" cam will be nostalgic for sure, but it will be down 20-30 hp to a modern camshaft that's smaller. If I remember correctly, it has 100° of overlap (or maybe a hair more). Jay's first camshaft in his cylinder head test mule engine had 102° and it was just pushing power out the exhaust.
You are 100% right, and the power is as much of an issue as is the unburned fuel hitting the O2 sensor, assuming he wants it to work as one. WB O2 sensors are better than ever, and the ECMs are smarter than ever, but none of them like excessive overlap
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I can only tell you here in TX with 10.5:1 old school iron heads and a decent hydro roller, it takes 50/50 mix of 91/VP110 to keep the plugs clean. Above 11 (old dragster motor was 11.5) I'd run straight 110. That's 9.50/gallon at the track or about $7.80/gallon in a 54 gallon drum. Last year anyway, probably more this year. Why I switched to methanol at $200/drum. The new motor is 12.5:1, marginal for 110 so next up is like 14.72/gallon for C12 (VP web site list price) if I want to run gas. Pass.
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I guess I should have been more clear on my plans. I plan on adding the EFI after I change out the cams. I will run a Holly 850 for the first 6 months.
I know the cam choice is not the best compared to the modern cams.
The reason I want to run the D can is 1 because I have it but the real reason is my dad had the D cam in his racing Cobra in 65. I just want too hear it for a while for the memories.
When I get the custom cam then I will install the EFI.
As to the gas available if I could find a system I would run CNG in it. I can buy it here for $1.69 a gallon at the local station. I run it in my 2013 F 250 and love it. I have been looking for a conversion that will fit in the trunk of the 63 but no luck so far.
I guess I will have to run gas and booster for the first 6 months and then re figure for the EFI with the modern cam set up.
I will try the Octanium and see how it works.
I will do one thing though. I have found a shop with a wheel dyno and I will have a dyno pull with the D cam and then go back after the cam change and make a comparison.
Thanks for the advice on the Rocket fuel I really don't to have to change out my pistons.
Another thing I really do appreciate all of the advice. It has been a few years since I have built a FE and I am really out of the mainstream on them. I have been building the 385 series and 351C engines along with the other customers engines since the 70's and I take all recommendations to heart.
so I want to say thanks for all the advice.
Greg
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The reason I want to run the D can is 1 because I have it but the real reason is my dad had the D cam in his racing Cobra in 65. I just want too hear it for a while for the memories.
Understandable.
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Skip the Rocket fuel. I've heard of a lot of guys burning holes in pistons with their stuff. Find you a drum of VP C12 or Sunoco 110.
Just curious about that statement. Are you referring to Rocket brand fuel? Any ideas why you've heard those stories, or why their particular fuel is bad? I only ask because Rocket is the brand used during Drag Week, and quite a few guys use it during the week of racing. Can't say that I remember a lot of issues with guys burning holes in pistons, and we're talking about quite a few serious engines.
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Skip the Rocket fuel. I've heard of a lot of guys burning holes in pistons with their stuff. Find you a drum of VP C12 or Sunoco 110.
Just curious about that statement. Are you referring to Rocket brand fuel? Any ideas why you've heard those stories, or why their particular fuel is bad? I only ask because Rocket is the brand used during Drag Week, and quite a few guys use it during the week of racing. Can't say that I remember a lot of issues with guys burning holes in pistons, and we're talking about quite a few serious engines.
I edited my post... Renegade was the fuel, not Rocket.
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Glad to here that. I have one 55 gallon drum in my storage and was planning on buying a drum every other month.
On my build I check the gaskets and they compress to 0.40 so I think I will have to blend my fuel.
Greg
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Hi. I just made drain plugs to except a Bosh two wire censor, that is were GM puts there's in the 350 blocks so we are going to try that. Leny
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Be sure to let us know how they work out.
Thanks
Greg
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Between the solid D cam and a solid roller I would think its gonna trigger those sensors from valve lash. Of course im not sure about that im just thinking out loud. Maybe a hydraulic roller would be quieter.
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You are more then likely right but if I don't try I won't know.
I have all ways been willing to try something that I don't know anything about and if it doesn't work then I will try something else.
I enjoy experimenting even if I make an ass out of myself.
Greg
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I would assume they can be programmed not to be so sensitive.
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I don't know.
These are a new idea to me and I am not sure how to program a stand alone system.
I was thinking of trying different ones until I came up with one that would work.
My friend who owns the junk yard will let me try any that he has there. All I have to do is label them to the car I took them off of for his inventory purpose's.
Greg
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Well there are alot of stock noisey motors out there. My jeep wrangler is alittle on the noisy side. they even have foan on the valve covers to hold down noise. the knock sensor on them are in the valley under intake.
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One of my thoughts was where to install it as I don't have a clue.
I guess that after I pull 20 or 30 of them I can get a basic ideal on where to put it.
I am going to start studying them for the next 9 to 14 days. We had the arctic front come in today and the temps are going to be below freezing for that time with the lows below zero. Since my shop is un heated this will give me something to do in that time.
Plan on wearing out my search engine in the coming weeks.
Greg
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A lot of Knock Sensors are mount to a very solid portion of the block where there is a lot of metal. Knock sensors on most BMW engines are located below the bottom of the cylinder coolant passage line before it joins into the lower case, they are mounted with long threaded bolts deep into the core.
I'd presume that the sonic shock wave of detonation can best be picked up on a thick solid portion of the block, and that the proximity to the combustion chamber is of less importance.
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That is a good point.
I was thinking of buying one of Summits engine run stands and bolting one of my extra engines to it and do some experiments.
That way I could move the sensor around and take some measurements and see what happens.
It may come to nothing but will give me something to do in my spare time.
Greg
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While my engine is out I am going to drill the pads that stick out on the sides that were for machining at the factory, so if the drain plugs do not work I can try them there. Leny
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Good ideal. I will give that a try.
Greg
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Not FE but a knock sensor related story. Bought a little POS car to drive to work. Olds Cutlass with a 3100 engine which are inherent rattlers. CEL was on and found the knock sensor
was unplugged. Well I got this, right? Plugged it back and went for a ride. Took so much timing out it would barely pull itself. Identifix said to remotely mount the sensor to the A/C
hose and ground it. Been running that way for 100K miles. Steve
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On a 1991 5.0L is that threaded hole for the knock sensor on top of the block behind the intake manifold? Earlier ones don't have a hole there. It doesn't appear to go anywhere.