Thank you for passing down your knowledge. Appreciate how thorough you are in explaining the proper type of plug and on indexing the plug to the head..
Great vid, what would you gap a motorcraft plug on a completely stock fox for best performance also which fuel octane would run in this set up? Thank you
I’d gap them .045”. If it will take 32* total timing on 87 octane without pinging, go ahead. In most cases you will need 91 octane to run optimal timing. As a rule of thumb you want to run the most volatile fuel you can with optimal timing and without pinging.
@@tecmotiondyno thank you could you also help me with a question I have an lx vert and it’s mint but when I drive it has Creeks and rattles from underneath going over small cracks in the rd. that I can’t figure out any advice greatly appreciated
You might have some suspension problems like worn or tired bushings, ball joints, or tie rod ends. You could also just have an old car with some creaks and rattles. I’d start with an inspection underneath and a close look at the suspension and chassis.
I know you are running meth, but if it was me I would go one colder for that combination. Autolite 3923 or NGK BKR6EY. It’s not that it won’t run, but one step colder would be a touch safer with no downside. I’d run the colder plug at .030” too, assuming you have a strong ignition which seems like a safe assumption.
I thought I had answered this question somewhere here already, but it doesn't look like it. I would use NGK TR5 or TR55 with an 0.045" gap in that application.
What spark plug WIRES do you recommend for these foxes? My car is mostly stock with only an E303 cam, Explorer GT40 intake, and an AOD. Love the content!
I like the MSD wires but they have gotten VERY pricey in recent times. The 9mm Ford Racing wires are a great choice and more reasonably priced these days. I just used a set of the Ford wires on a car to replace a damaged set of MSD wires a week ago actually.
@tecmotiondyno Funny you mentioned this. I just purchased this 88 LX coupe and the previous owner had a shop install brand new MSD wires but the boots are straight instead of angled and burned on the header causing several to arc. I figured I'd just replace them with the Ford Racing wires just like you suggested. Thanks for the help! Much appreciated sir!
@@royenri01 the MSD wires can be bent but if you bend them too extremely you will have problems. I worked on one just yesterday with an MSD set where I had to straighten the #1 wire to put it back on, and in the case of #1, there was really no reason for someone to have bent it.
Awesome video. Learn something new everyday. I went with Autolite 3924 on my trickflow 170cc head and supercharger at 10lbs of boost. I was debating if I should go a step colder to 3923?
I would have gone one colder, like the 3923 or BKR6EY in the NGK lineup, especially if you don’t have an intercooler. The 3924’s will run fine, but my choice would have been one step colder for your combination.
I'm no encyclopedia of Autolite numbers, especially for stock heads. In the NGK lineup I would think about UR6 for this application, which is 1 heat range colder than stock. Lots of guys get away with stock or UR5 plugs with that combination too.
what do you think about cutting back the Ground Strap ?? I have 2 sets of SP one NGK and one Autol 3924 with cutted Straps ..what I m running right now ..hard to say whats better ... Side Gaped ..they say ... forgot the name ....
I know guys do this to try to unshroud the spark kernel and it is supposed to help. I have never tried it myself but I have tested indexing in back to backs on the dyno and it DOES work on these pushrod motors.
I have a NA 347 that was tuned and ran great but had the tapered seated heads installed luckily I got them all out and replaced with the proper washer seat but I used the same gap that was on the previous plugs which I saved just in case. I think the tuned gap was around .32 , does that change with the correct longer washer seat plugs? Like can I use the same gap?
I normally recommend .045” if the car is NA and .030” if the car is supercharged or turbo as a starting point. Those gaps are good unless the car is well outside the norm in terms of the parts and power.
By the way, there is a video coming out tomorrow at noon Mountain Time on five things that are usually wrong with these cars, and I talk about one that I did recently which had the wrong plugs and a prior dyno, and when I fixed the plug problem and retuned it, I picked up 20 RWHP, so they can make a real difference at the top end too. Take a look at that video tomorrow ...
You're a legend dude, I'm gonna download your videos and put them on a DVD 😂. I just bought a Mark VII and you sir have knowledge I require.
There is a lot of tech content on here if you look through the back catalog on my channel. Thanks for watching!
Love your channel. I’m a veteran of the pushrod 5.0 but learn something every time I watch.
Thanks for your compliment, and thanks for watching!
Thank you for passing down your knowledge. Appreciate how thorough you are in explaining the proper type of plug and on indexing the plug to the head..
Glad it helped you out. Thanks for watching!
Just found your channel today!! I’m on my 6 video!! Love your presentation style and the info is awesome. Thanks for sharing!!
Glad you are enjoying it, and thanks for watching!
Thank you again Matthew. Your channel keeps being an extreme help as I build my Fox. Indexing the plugs for gt40p plugs was a mystery to me.
I’m glad it is helping you out. Feel free to share it around to anyone else you think might benefit from it!
Great info! Never knew about indexing the plugs!
Glad to help!
Great vid, what would you gap a motorcraft plug on a completely stock fox for best performance also which fuel octane would run in this set up? Thank you
I’d gap them .045”. If it will take 32* total timing on 87 octane without pinging, go ahead. In most cases you will need 91 octane to run optimal timing. As a rule of thumb you want to run the most volatile fuel you can with optimal timing and without pinging.
@@tecmotiondyno thank you could you also help me with a question I have an lx vert and it’s mint but when I drive it has
Creeks and rattles from underneath going over small cracks in the rd. that I can’t figure out any advice greatly appreciated
You might have some suspension problems like worn or tired bushings, ball joints, or tie rod ends. You could also just have an old car with some creaks and rattles. I’d start with an inspection underneath and a close look at the suspension and chassis.
Trickflow heads, Autolite 3924 12lbs of boost gapped at 25 and runs perfecto
I know you are running meth, but if it was me I would go one colder for that combination. Autolite 3923 or NGK BKR6EY. It’s not that it won’t run, but one step colder would be a touch safer with no downside. I’d run the colder plug at .030” too, assuming you have a strong ignition which seems like a safe assumption.
Thanks for the info Matthew the plug indexing was enlightening ⚡for sure.
It can make a genuine difference.
Thank you for sharing this video I really appreciate it keep up the great videos
Thanks for watching!
Thanks for watching!
What are the right plugs and gap for a 85 fox with 40 p heads.
I thought I had answered this question somewhere here already, but it doesn't look like it. I would use NGK TR5 or TR55 with an 0.045" gap in that application.
@@tecmotiondyno thank you
Great info on the indexing!
It’s an old but effective technique.
thank you.
You are welcome!
i have a 91 lx all stock what gap do i use ...ford dais 54 tou say 45
I recommend 0.045" on a car like that.
What spark plug WIRES do you recommend for these foxes? My car is mostly stock with only an E303 cam, Explorer GT40 intake, and an AOD. Love the content!
I like the MSD wires but they have gotten VERY pricey in recent times. The 9mm Ford Racing wires are a great choice and more reasonably priced these days. I just used a set of the Ford wires on a car to replace a damaged set of MSD wires a week ago actually.
@tecmotiondyno Funny you mentioned this. I just purchased this 88 LX coupe and the previous owner had a shop install brand new MSD wires but the boots are straight instead of angled and burned on the header causing several to arc. I figured I'd just replace them with the Ford Racing wires just like you suggested. Thanks for the help! Much appreciated sir!
@@royenri01 the MSD wires can be bent but if you bend them too extremely you will have problems. I worked on one just yesterday with an MSD set where I had to straighten the #1 wire to put it back on, and in the case of #1, there was really no reason for someone to have bent it.
I’m running afr 185 HCI 347 what plugs should i get??
If it is NA I would use NGK FR5
Awesome video. Learn something new everyday. I went with Autolite 3924 on my trickflow 170cc head and supercharger at 10lbs of boost. I was debating if I should go a step colder to 3923?
I would have gone one colder, like the 3923 or BKR6EY in the NGK lineup, especially if you don’t have an intercooler. The 3924’s will run fine, but my choice would have been one step colder for your combination.
@@tecmotiondyno thank you for the quick reply !
Got a question… what kind of spark plug should I run on 1990 stock heads and ProCharger on 8 psi ? Ngk and Autolight numbers
I'm no encyclopedia of Autolite numbers, especially for stock heads. In the NGK lineup I would think about UR6 for this application, which is 1 heat range colder than stock. Lots of guys get away with stock or UR5 plugs with that combination too.
Subscribed. Love your channel, what should we gap our fox bodies I might have missed that, I have GT40p heads and a e303 cam
NA I would gap them .045”.
wow he knows mustang!!! Rodney from 5.0 tussin channel would even get some faster MPH racing... awesome info
Thanks for your glowing complement and thanks for watching.
what do you think about cutting back the Ground Strap ?? I have 2 sets of SP one NGK and one Autol 3924 with cutted Straps ..what I m running right now ..hard to say whats better ... Side Gaped ..they say ... forgot the name ....
I know guys do this to try to unshroud the spark kernel and it is supposed to help. I have never tried it myself but I have tested indexing in back to backs on the dyno and it DOES work on these pushrod motors.
I have a NA 347 that was tuned and ran great but had the tapered seated heads installed luckily I got them all out and replaced with the proper washer seat but I used the same gap that was on the previous plugs which I saved just in case. I think the tuned gap was around .32 , does that change with the correct longer washer seat plugs? Like can I use the same gap?
I normally recommend .045” if the car is NA and .030” if the car is supercharged or turbo as a starting point. Those gaps are good unless the car is well outside the norm in terms of the parts and power.
By the way, there is a video coming out tomorrow at noon Mountain Time on five things that are usually wrong with these cars, and I talk about one that I did recently which had the wrong plugs and a prior dyno, and when I fixed the plug problem and retuned it, I picked up 20 RWHP, so they can make a real difference at the top end too. Take a look at that video tomorrow ...
@@tecmotiondyno Awesome and thank you so much for taking the time to reply!