Hood bump stops

[Bitsyncmaster]

I bought new bump stops from ED but looks like on my car his bolts are to short. My hood does sit pretty high but I can't get the bolts to grab enough thread in the body to hold. Well it also turns out my "crash blocks" don't line up and it also was set to close to the stop and it broke his plastic dome off when I shut the hood.

Anyway, I'm going to make my own bump stops using a commercial threaded rubber bumper (8-32 thread). I will turn some 8 mm 1.25 bolts down on the head and drill and tap for 8-32 screw. My OEM stop is 1.9" long.

Anyway, looks like I need to move those "crash blocks" to line up with the bump bolt. The photo shows my passenger side (look at the rubber ring marking). Drivers side is a little less offset.

[Timeless]

I have 1 set of stainless bump stops remaining if you're interested. They work perfectly.
6946469465

[Bitsyncmaster]

I have 1 set of stainless bump stops remaining if you're interested. They work perfectly.
6946469465

They look to short and I think I want the rubber on top.

[Timeless]

Length is ok at least on my car. I was thinking about rubber boots/caps but I like the way they look without.

[82DMC12]

Chris Miles sells some hood bump stops as well as rear engine cover bump stops. I have all four and they look/work great.

Andy

[David T]

The way I adjust the bump stops starts with the latch. Remove or screw the bump stops all the way in and adjust the latch so the edges of the hood (where the bump stops are) is slightly lower then the fenders. You will have to enlarge the holes in the latch to do that. Now screw the stops up to get the corners even with the fenders. Now the corners won't shake as you drive. When you are done use some black RTV on the bump stop's threads so they don't leak. Line up the brackets so they will capture the bump stops if they ever have to.

[Bitsyncmaster]

I got my 50 mm stainless bolts and rubber bumpers yesterday. I drilled the hole for the 8-32 bumper screw but tapping that hole in 304 stainless is not easy. I ordered some new taps. My old ones won't do it. I turned the bolt head down to 0.125 thickness but still think the bumper may be a little high. Will see if that rubber will cut with my lathe but it may need to be sanded to remove some of the rubber.

Was looking at the engine cover bumpers. Those look like 5 mm screws so I will look into what I can machine to use the same bumpers as I'm using in the front.

[Timeless]

Was looking at the engine cover bumpers. Those look like 5 mm screws so I will look into what I can machine to use the same bumpers as I'm using in the front.
I have these and they are perfect and fit flush when installed.

https://deloreanindustries.com/19-buffer/

[Bitsyncmaster]

Well the new 8-32 taps don't work either. I'm going to try a forming tap next. What the forming tap does is press the metal around the hole (it does not cut). You use a larger hole for that type of tap. If all this fails I will have to use regular steel.

[Bitsyncmaster]

I just thought of something better. If I can find liquid rubber, I can just make bumpers without any machining. Has anybody done any liquid rubber work? Maybe, FlexSeal.

[Bitsyncmaster]

I thought of another idea. Just use one of those self stick bumpers on the end of my bolt. I will machine the bolt head flat and machine a counter sunk area so the bumper cannot slide sideways (I guess it can get really hot in the summer). I have a ton of those bumpers in clear rubber.

[ssdelorean]

I thought of another idea. Just use one of those self stick bumpers on the end of my bolt. I will machine the bolt head flat and machine a counter sunk area so the bumper cannot slide sideways (I guess it can get really hot in the summer). I have a ton of those bumpers in clear rubber.

Those clear self sticking rubber bumpers will yellow and crack with time. I have used several under glass for indoor tables in a normal temperature. I would think they will last even shorter in the trunk when the sun beats down on the hood all day. Well, if your car spends most it's life in the garage then life expectancy may be the same. About a year or so?

I would opt for a solid dark rubber. Or those felt pads.

[Bitsyncmaster]

My mind never stops. Here is the latest idea. After machining the head of the bolt, I will PLASTIC DIP the heads. Maybe one or two times. I will machine something to do the same on a 5 mm screw for the rear engine cover bumps.

This is something most anyone can do since you can probably just put a bolt in your drill press and file the shape.

In my photo is the OEM bumper with the rubber cover off (It fell apart). Interesting they just machined a 50 mm bolt an installed or potted the rubber cover.

[WHO1DMC]

My mind never stops. Here is the latest idea. After machining the head of the bolt, I will PLASTIC DIP the heads. Maybe one or two times. I will machine something to do the same on a 5 mm screw for the rear engine cover bumps.

This is something most anyone can do since you can probably just put a bolt in your drill press and file the shape.

In my photo is the OEM bumper with the rubber cover off (It fell apart). Interesting they just machined a 50 mm bolt an installed or potted the rubber cover.Dgo sells these. There stainless for about 20 bucks.
Great minds think alike!



Dave B.https://uploads.tapatalk-cdn.com/20230323/a2ce7ad4cbde3f10f946d56d0cefc181.jpg

Sent from my SM-G991U1 using Tapatalk

[Timeless]

Dgo sells these. There stainless for about 20 bucks.
Great minds think alike!

Dave B.
I have a pair ready to go - he passed on them.

[WHO1DMC]

I have a pair ready to go - he passed on them.Well apparently I wasn't paying attention.





Dave B.

Sent from my SM-G991U1 using Tapatalk

[Bitsyncmaster]

I dipped those two in PLASTI DIP which I bought at hardware store for about $14. What you want to do is tip and rotate it for about 15 minuets if you don't want a drip at the bottom.

Not something you want to do if you plan to sell them. You would need to make up a potting form. There may be better rubber potting but when I looked all the two part rubber was very expensive.

[Bitsyncmaster]

The Plasti Dip came out very nice. Don't know how it will stand up over time yet.

[DMC-Ron]

Dave,
Those look good! If it turns out they wear through quickly and you're looking for another solution, perhaps modifying chair or cane silicone tips might be an option. There are small diameter ones available. It's likely that you would cut or saw off the some of the top to shorten, then use Goop to secure it to the bolt head.

Ron

https://www.amazon.com/dp/B09X9H3FCS/?coliid=I3C90S6HUYVLIE&colid=IBWSVQ2ZHQ6L&psc=1&ref_=lv_ov_lig_dp_it

[Bitsyncmaster]

Did the engine cover bump stops. What I would do again is just cut some aluminum rod, drill and tap a blind hole, then locktite a threaded rod into it.

[Bitsyncmaster]

Well I got my 8-32 form tap and was able to tap my first attempt. And I can machine the rubber using high speed turning and very light cuts. So I think I'm going to be using this for my car. I like the thicker rubber padding and know it should last.

All I can think of with the problem tapping that 304 SS is when I drilled the hole it "work hardened" the SS. I tried to heat it and cool it fast and even tried cooling slow but I still could not tap it using the normal cutting tap. Anyway, I bet using a form tap for aluminum would be great since you don't get chips and would not have to keep backing out the tap to clear chips.

So this SS is a little discolored from my heating when I tried to soften the metal.

I'm thinking of maybe using a bigger bolt for the engine cover bumps so I can use the same rubber bumpers for those.

[Bitsyncmaster]

Interesting tidbit. My drivers side OEM bump stop is 37 mm long. The passenger side is 50 mm. I wonder if this is normal on all of our cars.

Now I see why Ed's parts were to short when I tried it in the passenger side.

[MrChocky]

I just installed the DGo ones, but Chris Miles has yet another style for both hood and engine cover.

https://dmctalk.org/showthread.php?19460-DeLorean-Parts-By-Chris-Miles

[Bitsyncmaster]

I do think the passenger side was always 50 mm long and the drivers side 40 mm. I had to cut my new one for it not to bottom out on the drivers side. The parts list does show different part numbers but it says 2 of each in the parts list.

Maybe it's just some VINs that require the two different lenghts.