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General Forums => The Mess Hall => Topic started by: mrcabinet on September 14, 2009, 01:44:08 PM
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While anxiously awaiting for my 62mm TB from Bounty Hunter, I've been contemplating a different way of grinding out the manifold. Using a dremel obviously works, but it seems messy and would be difficult (for me at least!) to get a nice round hole with. I have a slew of hole saws and was thinking about using the gasket as a pattern to make a jig out of MDF, bolt it to the manifold, and then cut it with a hole saw. This would be perfectly round and decrease the amount of chips flying around.
My only concern is that the closest I have to 62mm is 2 1/2", which is 63.5mm. Would the slightly larger hole be O.K.? Should I trim the gasket opening larger as well? I don't know if the slight lip of the gasket could get sucked inside.
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I wouldn't go larger.
The biggest problem I had with the chips was the gas that is inside the manifold. The chips stick to it so it's kinda hard to get them out. You would have the same problem with a hole saw plus you would have the MDF chips too. Just make sure you tape the inside of the opening better than me ;)
If you mark the hole with a sharpie the dremel way can be fairly close to being a perfect circle. If there is some slight imperfections in the circle it's not going to matter that much.
The chips that get on the outside of the manifold vaccume up pretty easily. Whatever you can't get to just hose it all down once it's all back together.
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i'd try it, 1.5mm larger is better for flow than a rough azz hole IMHO.\
The only problem is I've never seen a hole saw that runs true. There's also some ribs in there you'll still need to deal with after using the hole cutter.
Dremel w/ stone brings the suck - very slow. Use a Dremel rasp attachment or whatever its called and then follow w/ a stone or sanding drum for evening the hole out once you have it real close w/ the rasp. Even the rasp is slow going but a stone alone would take all freaking day.
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i'd try it, 1.5mm larger is better for flow than a rough azz hole IMHO.\
The only problem is I've never seen a hole saw that runs true. There's also some ribs in there you'll still need to deal with after using the hole cutter.
Dremel w/ stone brings the suck - very slow. Use a Dremel rasp attachment or whatever its called and then follow w/ a stone or sanding drum for evening the hole out once you have it real close w/ the rasp. Even the rasp is slow going but a stone alone would take all freaking day.
There is 4 ribs that you get into a little.
The dremel with a rasp cuts the AL pretty fast. If you follow your line that you marked the edge is not ragged.
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did you guys remove the manifold to bore it out or did you just bore with it on the engine and stuffed the hole to catch all the junk?
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did you guys remove the manifold to bore it out or did you just bore with it on the engine and stuffed the hole to catch all the junk?
Not to sound weird but, I just stuffed my hole :lol:
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While anxiously awaiting for my 62mm TB from Bounty Hunter, I've been contemplating a different way of grinding out the manifold. Using a dremel obviously works, but it seems messy and would be difficult (for me at least!) to get a nice round hole with. I have a slew of hole saws and was thinking about using the gasket as a pattern to make a jig out of MDF, bolt it to the manifold, and then cut it with a hole saw. This would be perfectly round and decrease the amount of chips flying around.
My only concern is that the closest I have to 62mm is 2 1/2", which is 63.5mm. Would the slightly larger hole be O.K.? Should I trim the gasket opening larger as well? I don't know if the slight lip of the gasket could get sucked inside.
i was actually planning to do the same thing - use the 2-1/2'' bimetal holesaw - cuts fairly accurate, maybe 1/16 over 2-1/2 you just gave me a better idea how to do it with the mdf (EDIT: :clap:) but i will use 5/8 plywood that i have around (i was planning to try and use a flat bar inside the opening bolted thru 2 of the holes with some longer 4mm metric bolts and use it to center the holesaw, but this way is easier, it would center itself on the inside of the plywood) - if i get around to do it before you bore out yours i'll let you know how it goes
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I would use a 2" sanding drum and work slowly. Cutting it to 2.5" leaves no margin for errors especially if you're using a hand drill.
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I'm sorry but I have to ask........what is an MDF ?
Thanks,
Vance
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Medium density fiberboard
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like he ^ said - it is commonly used in painted kitchen cabinet doors (and even the cabinets themselves). Also, it is used for boom boxes and speaker boxes as it is very easy and friendly to the router bits (you can use routers to give it various profile edges) and it can be glued with no seam. Can be painted and also can be covered with fabric.
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just the intake port needs to be enlarged correct?
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just the intake port needs to be enlarged correct?
Where the TB and the manifold meet.
http://4bangerjp.com/forums/index.php/topic,6008.0.html (from the FAQ's)
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I was rummaging around in the shop today and came across a 2 3/8" hole saw. That equates to 60.325 mm. The hole will probably "run-out" some during the cut, so I'll just use that then a sanding drum to get to 62mm. Hmmm, I do have a cylinder hone. Maybe that would do for the final grind.
I have about 60 sheets of 3/4" MDF, so I'll most likely use that as my guide and countersink the bolt holes so I don't have to buy longer ones.
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like he ^ said - it is commonly used in painted kitchen cabinet doors (and even the cabinets themselves). Also, it is used for boom boxes and speaker boxes as it is very easy and friendly to the router bits (you can use routers to give it various profile edges) and it can be glued with no seam. Can be painted and also can be covered with fabric.
it's fun to quote myself - i just realized his nickname is mrCabinet - :lol:
i guess no question why the extra MDF lying around...
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Yeah, that nickname goes back almost 25 years, to when I ran the display shop for a well known Japanese knife company (starts with a K). The guys from corporate used to call me Mr. Display but, after designing and building a really trick cabinet for a trade show, one of the V.P.s came up to me and said "Orkay, you now be Meester Cabinet!". Its stuck with me ever since.
If you want to see what can be done with MDF cabinets, check out our website at www.kisscabinet.com.
I'm going to be drilling out the manifold today. I'll let you know how it works.
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Yeah, that nickname goes back almost 25 years, to when I ran the display shop for a well known Japanese knife company (starts with a K). The guys from corporate used to call me Mr. Display but, after designing and building a really trick cabinet for a trade show, one of the V.P.s came up to me and said "Orkay, you now be Meester Cabinet!". Its stuck with me ever since.
If you want to see what can be done with MDF cabinets, check out our website at www.kisscabinet.com.
I'm going to be drilling out the manifold today. I'll let you know how it works.
lol - pretty cool story
take some pics for us when you play with the holesaw and mdf - looking forward to see the result
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I did the drilling Saturday and all in all it went pretty well. It took about an hour and a half total, including the time to make the jig. The 2 3/8" hole saw was the right size to go with. Because of the run-out during the drilling, the hole came out at 61.78mm. Since the gasket measured 61.74 and the TB 61.89, it was just about perfect.
I ended up using a scrap piece of 5/8" MDF, which let me use the bolts without having to countersink the holes, and used the gasket as a template. The bolt holes were drilled slightly oversized so I could center it over the manifold opening.
(http://i230.photobucket.com/albums/ee204/mrcabinet/IMG_0146.jpg)
(http://i230.photobucket.com/albums/ee204/mrcabinet/IMG_0147.jpg)
(http://i230.photobucket.com/albums/ee204/mrcabinet/IMG_0149.jpg)
Remember to take the bit out of the center of the hole saw!
(http://i230.photobucket.com/albums/ee204/mrcabinet/IMG_0150.jpg)
The actual cutting took maybe two minutes, tops.
(http://i230.photobucket.com/albums/ee204/mrcabinet/IMG_0151.jpg)
And here you have a nice round hole. A few swipes with a sanding drum in a Dremel cleaned it up and left it right at 62mm.
(http://i230.photobucket.com/albums/ee204/mrcabinet/IMG_0152.jpg)
Would I do it again this way? You bet! But I don't know if it would be worth it to run out and buy a hole saw just for this.
I did remove the top two vacuum fittings and taped over the bottom two, then stuffed the holes with rags and gave them a good coating of grease for the shavings to stick to. If I were to do it again I think I'd stuff the holes and then use shaving cream to catch the debris (much easier clean up).
I put everything back together and the rig fired right up. No screaming idle, whistles or other issues. After punching it, idle speed drops to 1050 rpms and then drops right down to 750. I'm sure this will go away once the ECU re-learns itself. The throttle response is much crisper and low / midrange power shows a definite improvement. On the freeway it will hold 70 in fifth on a flat stretch and give a little increase now when I mash it to the floor. It still needs fourth on the uphill grades but will now actually pick up speed on those slopes. From what I've read, it should improve over time.
All in all, for less than a hundred bucks and an hour or two of your time, it is a great modification to do. BTW, Bounty Hunter is a great guy and you won't be disapointed if you get your TB from him.
Next up: Electric Fan!
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Nice. Glad it worked out. Looks clean.
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:clap: :clap: :clap:
awesome, looks great - nice work :thumb:
thanks a lot for the pics
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Now that's the correct way to grind the intake, mine was much more butch :baby:
Good write up too.
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Now that's the correct way to grind the intake, mine was much more butch :baby:
Good write up too.
i am really jealous that i didn't come up with this :'(
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FYI, the manifold measured 55mm before drilling - the same size as the stock 4.0l TB at the bottom. The 2.5l TB measured 48mm at the bottom and the 62mm was, well, 62mm. That's a 22 1/2% increase over the 2.5l TB! I am thinking about adding a heavier return spring on the TB or gas pedal arm. Since it is more responsive now, bumps in the road that affect the right foot transfer to the throttle more noticeably now.
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Sharpxmen -
Don't feel bad. The only reason I thought of this is because it is exactly what we do in the field if we have to enlarge existing holes in cabinets.
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I guess this means I now have to go out and buy me a new holesaw of the right size... I already got the 62mm TB in place, so this would be a nice addition! I am also thinking about taking out the TB and boring it smooth (mine is the Helix type) for better airflow...
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It looks clean. Let us know if it the mods helps.
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FYI, the manifold measured 55mm before drilling - the same size as the stock 4.0l TB at the bottom. The 2.5l TB measured 48mm at the bottom and the 62mm was, well, 62mm. That's a 22 1/2% increase over the 2.5l TB! I am thinking about adding a heavier return spring on the TB or gas pedal arm. Since it is more responsive now, bumps in the road that affect the right foot transfer to the throttle more noticeably now.
actually it's 66.48% increase: 48mm vs 62mm - the surface thru which the air goes thru is PI*Diameter^2/4 (EDIT: or PI*Radius^2 which is square radius times 3.14 - not sure if the way i posted that formula made sense in the first attempt) so directly proportional to the square of diameter.
Sharpxmen -
Don't feel bad. The only reason I thought of this is because it is exactly what we do in the field if we have to enlarge existing holes in cabinets.
not feeling bad at all, just being silly - like i said i was trying to figure out a way to use the holesaw, your solution was awesome (didn't occur to me to center it on the outside, i was looking for a way to use the center bit - I should send you one of those staples "that was easy" buttons as a gift for this)
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Well of course its 66.48% for the whole thing - I was just referring to the hole diameter at the bottom of the TB, and it was way too early for me to do math. 66.48 certainly sounds more impressive though!
I'll keep an eye out for that easy button.
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I am thinking about adding a heavier return spring on the TB or gas pedal arm. Since it is more responsive now, bumps in the road that affect the right foot transfer to the throttle more noticeably now.
The increase in throttle response reinforces the need to drive with only your toes on the throttle pedal, any more foot and you get a lot of throttle bounce.
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I am also thinking about taking out the TB and boring it smooth (mine is the Helix type) for better airflow...
I can take your helix spacer as partial trade towards a smooth 62mm spacer. If it's of any help.
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I didn't think it would work as well as it did...great job man! :beers:
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I can take your helix spacer as partial trade towards a smooth 62mm spacer. If it's of any help.
If I were still in Miami, I would have done it; but now the Jeep is in Panama, so shipping would kill me. It's probably cheaper to have someone do it there; besides, I have a friend in Panama with a lathe (actually, a complete shop) who can probably do it for me for free... I just got to find the time during one of my monthly trips to panama to do this!
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I used Playdough to block the holes on my intake when I ground it.
Used a die grinder with a carbide burr and used the new
TB to scribe a line around the hole to see how much needed cut.
This is a way sweeter idea......
Dave
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I used Playdough to block the holes on my intake when I ground it.
Dayum thats a great idea too! I used wadded duct tape balls which worked pretty good but this would work better.