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Another Twinky project https://ausmini.com/forums/viewtopic.php?f=5&t=93407 |
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Author: | simon k [ Sat Aug 13, 2016 10:20 pm ] |
Post subject: | Re: Another Twinky project |
attention to detail - it doesn't take that much effort to do it properly |
Author: | zulu_warrior1976 [ Tue Aug 16, 2016 5:37 pm ] |
Post subject: | Re: Another Twinky project |
zulu_warrior1976 wrote: Love those graphics of the 3 minis in your footer! How did you do that? ? anyone help? |
Author: | Scoop [ Tue Aug 16, 2016 5:49 pm ] |
Post subject: | Re: Another Twinky project |
zulu_warrior1976 wrote: zulu_warrior1976 wrote: Love those graphics of the 3 minis in your footer! How did you do that? ? anyone help? I'm only guessing but I think its just an image saved in your signature. |
Author: | timmy201 [ Tue Aug 16, 2016 6:04 pm ] |
Post subject: | Re: Another Twinky project |
It's called mini selecta. Modify the mini, click save, crop off the extra, upload the image and paste BBCode to your signature (don't think it works on all mobile devices though) http://www.localminichat.co.uk/oildrippers-miniselecta/ |
Author: | RetroStyle [ Tue Aug 16, 2016 6:56 pm ] |
Post subject: | Re: Another Twinky project |
Irrelevant to thread. |
Author: | Scoop [ Tue Aug 16, 2016 6:59 pm ] |
Post subject: | Re: Another Twinky project |
Thanks or that link Timmy, very cool. |
Author: | MiniBrad [ Tue Aug 16, 2016 7:00 pm ] |
Post subject: | Re: Another Twinky project |
timmy201 wrote: It's called mini selecta. Modify the mini, click save, crop off the extra, upload the image and paste BBCode to your signature (don't think it works on all mobile devices though) http://www.localminichat.co.uk/oildrippers-miniselecta/ One day I'll learn how to do this. Brad |
Author: | DOZ [ Tue Aug 16, 2016 8:24 pm ] |
Post subject: | Re: Another Twinky project |
looking good! |
Author: | zulu_warrior1976 [ Tue Aug 16, 2016 10:10 pm ] |
Post subject: | Re: Another Twinky project |
timmy201 wrote: It's called mini selecta. Modify the mini, click save, crop off the extra, upload the image and paste BBCode to your signature (don't think it works on all mobile devices though) http://www.localminichat.co.uk/oildrippers-miniselecta/ Thanks. Irrelevant to thread or not, that's awesome! Cheers. |
Author: | Mokesta [ Tue Aug 16, 2016 10:15 pm ] |
Post subject: | Re: Another Twinky project |
I have been doing a bit of homework on the hole plugging. There are 4 different diameter holes to plug. The existing head studs are already tapped to 3/8x16tpi. The other 3 holes are: Use -- Approx diameter Water -- 6.2mm to 6.4mm (1/4 inch nominal) Push rod -- 10.2mm to 10.5mm water -- 12.6mm to 12.75mm (1/2 inch nominal) I notice that the head studs are the only UNC threads in the block. All the others that I found were UNF. So I looked at UNC, UNF and Metric thread sizes. Options are: 6.3mm water holes --> Drill 6.6mm and tap 5/16x18, Drill 6.9mm and tap 5/16x24 or Drill 7mm and tap M8x1.0 10.2mm push rod holes --> Drill 10.8mm and tap 1/2x13, Drill 11.5mm and tap 1/2x20 or Drill 10.8mm and tap M12x1.25 12.7mm water holes --> Drill 13.5mm and tap 5/8x11, Drill 12.9mm and tap 9/16x18 or Drill 12.75 an tap M14x1.25 That's all well and good but you need to get a drill, a tap set and something to thread into the hole so if they aren't common sizes you're stuffed. The 9/16UNF size appears rare and the fine metric threads are also a bit scarce in the larger size. Looks like UNC is the way to go. What about the issue of the inserts being too hard and the drill wandering when drilling for the new holes? I looked at the pattern and there are only two types of holes that overlap the insert and the new hole. These are the outer two new studs on the engine number side overlapping with the old stud positions and the new water drillings on the same side overlapping with the 1/4 inch plugged holes. That means, apart from the head skimming operation, the strength of the inserts for the push rods and the 1/2 inch water holes can be whatever. I looked around for screws, bolts or threaded rod that would be about the same strength as typical cast iron engine block material. This is actually hard to do because the yield strength of most commercial bolts is about double that of the cast iron. Really low grade "standard hardware grade" bolts appear to be metric coarse or BSW. I see that someone on here many years ago (user jspink, anyone got contact details for him?) got threaded rod turned out of grey cast iron. The cast iron is available as a 25mm bar stock so that is an option I am getting pricing on. Anyone care to recommend UNF, UNC or Metric and a reason? Is there any difference in the ease of tapping between UNC and UNF? Do I want more or less cavity for sealant / locking compound? The UNC appears to allow a looser fit. How common are the sizes in the list above? The UNC and UNF taps appear to be relatively easy to get. Most of us probably have the smaller sizes already for cleaning out threads. I probably shouldn't worry about any of this and just hand the block to Matt but there is some fun in the researching. M |
Author: | Scoop [ Wed Aug 17, 2016 8:23 am ] |
Post subject: | Re: Another Twinky project |
The holes that need plugging, couldn't you just bronze them up rather than worrying about drilling/tapping them? Or am I missing something? |
Author: | 69k1100 [ Wed Aug 17, 2016 10:58 pm ] |
Post subject: | Re: Another Twinky project |
Any reason for matching plugs to the block in terms of yield? I thought thermal expansion would be more relevant. Other considerations, the smaller the plug the less area exposed to pressure, and the head studs aren't cast iron. |
Author: | drmini in aust [ Thu Aug 18, 2016 3:00 pm ] |
Post subject: | Re: Another Twinky project |
My 2c re drill wander. Yes it is a serious problem. I have had experience drilling into 2 or more dissimilar metals, when I used to modify Mini rocker posts for an offset shaft +Corolla rockers. In this case it was drilling steel + iron + nickel bronze in the lathe. So I used a slot drill, then bored to finish size. My solution for your block mod- don't use a twist drill. Set it up on a mill, and use a slot drill instead. Yes you can plunge cut with these. |
Author: | simon k [ Thu Aug 18, 2016 8:22 pm ] |
Post subject: | Re: Another Twinky project |
drmini in aust wrote: My 2c re drill wander. Yes it is a serious problem. I have had experience drilling into 2 or more dissimilar metals, when I used to modify Mini rocker posts for an offset shaft +Corolla rockers. In this case it was drilling steel + iron + nickel bronze in the lathe. So I used a slot drill, then bored to finish size. My solution for your block mod- don't use a twist drill. Set it up on a mill, and use a slot drill instead. Yes you can plunge cut with these. I was gonna ask if that was the best option... is it OK to use the slot drill to basically do a ~6mm pilot hole, then use a twist drill in to that, or will it still go off-centre? |
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