My goal was to build something better then what is offered for sale by others. I am amazed no one has taken my approach for the tensioner design/position..
Objectives: -To mount the alternator is a location that I did not have to modify my deck lid. -Affordable -Allow the use of a dog bone, preferably in the stock location -Allow the use of the alternator I had; 2000GTP style -Easy to make -Use readily available parts
Items required: -1/4" steel plate -1/4” steel “L” channel -Welder, or know someone w/ a welder -Saws All -Angle grinder/cutoff tool -Drill -Primer & paint -Stock SC tensioner w/ ribbed pully -Misc. nuts/bolts -78" or 78.5" 6-rib belt
To make the parts, I used 1/4" steel plate and "L" channel... The metal I sourced from an old plow chassis mount. It is also available from Lowe’s and HD for around $25-$30... A welder is needed or a friend who welds is also handy. A saws all was used to cut the shape and an angle grinder/cutoff tool also came in handy to fine-tune the shape. A drill will also be needed (I forget the drill bit size I used)...
First pic shows the rough-cut of the alt. bracket With the angle iron piece held in place Pic of the tensioner bracket rough-cut Tensioner bracket held together and in place on the DB mount Alt. bracket test fit on motor; I used 1 nut between the DB mount and alt. to get proper belt alighnment. socket is there to hold it in place while I measured. Alt. bracket partially welded and test fit Tensioner bracket test fit. I decided to mount my coil packs on top. You want the tensioner pully as close as possible to the DB mount, so the swing clears the SC snout. both brackets fit on motor w/ belt installed. I had to use a 1/16" thick washer behind the tensioner pully to bet perfect alignment. The belt I used is 78" long; a 78.5" belt bould prolly be perfect; but was wondering about stretch over time (still sure it would be fine though)... Parts primed. I used a bolt welded in to secure the tensioner pully. The bolt was press-fit into the hole and prolly did not need to be welded in. I also welded nuts to the back side of the alt. bracket to make it easier to service (nuts wouldn't fall to the ground when removing the alt. for service).
I will pot more pics one the paint has dried and assembled back on motor...
I really like my tensioner mount! It is VERY strong and I did not have to alter the dogbone mount in any way. The alternator mount is also super strong; as I added a lil piece of steel to the angle iron to the plate; to prevent the belt from pulling it...
I used 1/4" steel because the thickness positions the tensioner in almost the exact proper location; not too mention it has NO flex...
Any questions, please feel free to ask!
[This message has been edited by ALJR (edited 04-02-2011).]
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10:32 PM
PFF
System Bot
ace5514 Member
Posts: 692 From: west long branch, nj, usa Registered: Nov 2008
Without pictures,the thread is pointless and with photobucket there will be no pics in a few months.
Did you even read what I posted? Pics were to come as I forgot my USB cable in the office and was unable to upload pics last night!
Photobucket is the only pic hosting site I use. If you or someone else wants to cut/paste the pics to another host, feel free I am not doing this for profit or advertising, just trying to give some another option then to pay $300+ for mounts that arn't half as good as my style...
These were very easy to make once I figured out the position of everything. I am sure some one else could make these in 1/4 the time it took me... I am NOT a metal fabricator and I used simple tools...
Wish I could But w/o a plasma cutter or CNC, cutting the shape of the plate is kinda a PITA using a saws all... It would take me two hours to cut/fit the bracket using what tools I have; on top of another two hours to drill holes and weld it up... Thats 4 hours (at least) of labor on top of parts. That would put these in the price range of what others are selling them for... I would have to make ALLOT of these to justify spending $1000 for a decent plasma cutter... And any metal fabricator would charge me an arm and a leg to make such a small qty...
Would you really be willing to spend over $300 for these brackets when you could make them yourself for under $50?
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11:48 AM
Jfrost Member
Posts: 1092 From: Brookfield, IL Registered: Jul 2009
Wish I could But w/o a plasma cutter or CNC, cutting the shape of the plate is kinda a PITA using a saws all... It would take me two hours to cut/fit the bracket using what tools I have; on top of another two hours to drill holes and weld it up... Thats 4 hours (at least) of labor on top of parts. That would put these in the price range of what others are selling them for... I would have to make ALLOT of these to justify spending $1000 for a decent plasma cutter... And any metal fabricator would charge me an arm and a leg to make such a small qty...
Would you really be willing to spend over $300 for these brackets when you could make them yourself for under $50?
Good point, I'll have to keep this idea in mind for when I eventually swap in a 3800.
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11:58 AM
RotrexFiero Member
Posts: 3692 From: Pittsburgh, PA Registered: Jul 2002
I did something similar. I purchased a new alternator (forget what make) and bolted one ear to the block. It lined up perfectly and then just made some supports, two of them, from some flat steel. Worked fine. I cant understand paying $300 for a bracket. For goodness sakes you can purchase a Harbor Freight welder and make a bracket and the 3800 mounts to boot!!!
Love it ! Good ideas for when I do mine. One questions. the two bolts on the bottom Alt plate? How do they hold/attach to the bottom of the Alt. Just can't picture that in my head.
Maybe one more picture... Or maybe when you post the final pics it will be clear.
Love it ! Good ideas for when I do mine. One questions. the two bolts on the bottom Alt plate? How do they hold/attach to the bottom of the Alt. Just can't picture that in my head.
Maybe one more picture... Or maybe when you post the final pics it will be clear.
The newer style alt. (I believe 99+) has a flat portion that two bolts pass through. The bolts that are in my pic are just to keep paint from getting on the threads... Look at the 6th pic (the one that has the deep socket supporting the alt.), you can see one of the two bolt holes that will be used...
I will post more pics of the brackets when the paint dries; both on the motor and off...
Guess you beat me to the low-cost low-mount setup. Al's is very, very similar to what I was working on. The way of implementing a dogbone is a little different, but I like it!
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12:23 AM
07Hoffmannd Member
Posts: 404 From: St. Louis, Mo. U.S.A Registered: Apr 2008
my low mount cost $10 including in the price a new tensoner (not pictured, but if you need it i can show it). the only power tool you need is a drill. no welding required. and i used things i had available (including the stock alt, if you include that, your price will more than double). mine is not better than what is offered. but is suitable considering ive lifted the engine with my low mount. under $50 is easily done.
[This message has been edited by 07Hoffmannd (edited 10-16-2010).]
my low mount cost $10 including in the price a new tensoner (not pictured, but if you need it i can show it). the only power tool you need is a drill. no welding required. and i used things i had available (including the stock alt, if you include that, your price will more than double). mine is not better than what is offered. but is suitable considering ive lifted the engine with my low mount. under $50 is easily done.
How thick is that plate? Have you installed a belt on it yet? My bracket is 1/4" thick; with the belt installed and before I added the lil wedge brace, it would flex a little when squeezing the belt together. It does not move/flex at all now since the lil brace was welded in...
I also tried working w/ the pre-99 altenator style, but decided to use the newer style as it provided a more positive mounting position... when I was working with your style alt. I was using the same approch you have, but could not figure out an easy/cheap way for removing the flex...
[This message has been edited by ALJR (edited 10-16-2010).]
Guess you beat me to the low-cost low-mount setup. Al's is very, very similar to what I was working on. The way of implementing a dogbone is a little different, but I like it!
The dogbone mount is a stock part; I did not want to reinvent the wheel... Also did not want to machine it as others have dun; to mount the tensioner to it. That just seems like a bad idea and removes just about all structural intergrity from it. Defeating the purpose of even having one (dog bone mount) to begin with...
ohh ya MD, who mounted this motor the the 88 cradle? its crook'ed
[This message has been edited by ALJR (edited 10-16-2010).]
07Hoffmannd post that picture. The more ideas we all have the better to complete our projects. It's all food for thought.
I agree! My idea in not the ultimate, ideal design; rather another option. If this turns into the "reference" thread for 3800 low mount alts. that would be fine by me Having dozens of ideas in one thread (with a searchable title) would be a valuable resource to have...
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04:33 PM
Dennis LaGrua Member
Posts: 15143 From: Hillsborough, NJ U.S.A. Registered: May 2000
Here's one mounted for about $10 in steel. Some 1" W x 1/4" thick stock, a piece of 1x1 L channel about 12" L a few spacers and some hardened bolts. Its a very simple approach, requires no welding and it looks neat. However, it does use an alternator from a 99 Astro w 4.3L engine. Best of all you can change the plug next to it with ease.
------------------ " THE BLACK PARALYZER" -87GT 3800SC Series III engine, 3.4" Pulley, N* TB, LS1 MAF, Flotech Exhaust Autolite 104's Custom CAI 4T65eHD w. custom axles, HP Tuners VCM Suite. "THE COLUSSUS" 87GT - ALL OUT 3.4L Turbocharged engine, Garrett Hybrid Turbo, MSD ign., modified TH125H " ON THE LOOSE WITHOUT THE JUICE "
[This message has been edited by Dennis LaGrua (edited 10-16-2010).]
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08:57 PM
deezil Member
Posts: 779 From: St Louis Mo USA Registered: Mar 2010
Dennis, Do you have any better pics of that mount?
Its really not a mount. The alternator mounts directly to the block with a hardened bolt and spacer. There are two additional and simple brackets that hold the back and bottom firmly in place. The rear and bottom brackets are shown here:
------------------ " THE BLACK PARALYZER" -87GT 3800SC Series III engine, 3.4" Pulley, N* TB, LS1 MAF, Flotech Exhaust Autolite 104's Custom CAI 4T65eHD w. custom axles, HP Tuners VCM Suite. "THE COLUSSUS" 87GT - ALL OUT 3.4L Turbocharged engine, Garrett Hybrid Turbo, MSD ign., modified TH125H " ON THE LOOSE WITHOUT THE JUICE "
[This message has been edited by Dennis LaGrua (edited 10-16-2010).]
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10:06 PM
PFF
System Bot
deezil Member
Posts: 779 From: St Louis Mo USA Registered: Mar 2010
Nice work all you guys!! thanks for the info now i hate to say this but saves a lot of people from having to buy one from you know who, and pray he sends it to you.... denis, your set up is so stealth i had to study the pic for a half hour to see what you did! hope you guys don't mind me borrowing your designs when my time comes! al
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08:45 PM
07Hoffmannd Member
Posts: 404 From: St. Louis, Mo. U.S.A Registered: Apr 2008
Looks like it might hit the trunk wall, have you checked fitment for clearance there?
On mine?
Yes, I checked. I was using the sway bar as a reference point. On the stock cradle that is in the car now, if I look down my trunk wall, the back edge of the sway bar is just in front of the trunk wall (when looking down from above)... Wow, that heart typing... If it does not fit, I have two options; I could bang a dent into the trunk or I could reshape the lower alt. bracket so it pivits in more tords the block. Just have to make sure I have room for the connector on the alt...
what a good time for something like this to come about...
They have been around for awhile.
Unfortunately this guy took down his pictures, but it was pretty hilarious to follow the failed logic of the engine swap community even 2 years ago. This alternator mount hit both the trunk and would only work on an automatic, yet he wanted to sell them.
Unfortunately this guy took down his pictures, but it was pretty hilarious to follow the failed logic of the engine swap community even 2 years ago. This alternator mount hit both the trunk and would only work on an automatic, yet he wanted to sell them.
The problem with this other mount is that it located the alternator too high up where there is less room for clearance. Low mount means exactly that-down low. I would have to say that the fit of your alternator will be close. ------------------ " THE BLACK PARALYZER" -87GT 3800SC Series III engine, 3.4" Pulley, N* TB, LS1 MAF, Flotech Exhaust Autolite 104's Custom CAI 4T65eHD w. custom axles, HP Tuners VCM Suite. "THE COLUSSUS" 87GT - ALL OUT 3.4L Turbocharged engine, Garrett Hybrid Turbo, MSD ign., modified TH125H " ON THE LOOSE WITHOUT THE JUICE "
[This message has been edited by Dennis LaGrua (edited 10-18-2010).]
Originally posted by Dennis LaGrua: The problem with this other mount is that it located the alterantor too high up where there is less room for clearance. Low mount means exactly that-down low. I would have to say that the fit of your alternator will be close.
I just quadruple checked the clearance; I should have approx. 2" between the trunk wall and alt... Motor mounts are poly and I'm running a dog bone up top. So there should be more then enough clearance
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11:26 AM
darkhorizon Member
Posts: 12279 From: Flint Michigan Registered: Jan 2006
I had to clearance the trunk for this one. Stock 99 gtp alternator.
darkhorizon, could you measure the point from the block to the drivers side lower alt. bolt (outside block to inside alt.) for me? Could you shoe a pic of the "clearancing" you had to do?
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03:19 PM
americasfuture2k Member
Posts: 7131 From: Edmond, Oklahoma Registered: Jan 2006
