02-02-2018, 11:49 AM
guys, i'm listing a link here with an old rod bolt post for mcculloch engines.
worth reading.
it's hard to believe it was eight years ago this info was posted.
time flies.
heres the original post on Rear in case the links don't work here.
mcculloch rod bolt post 2010
i pasted the post below and the links still seem to work here
Howard ochocke » Mon Dec 27, 2010 1:00 pm
Who is a good source for small quatities of rolled-thread cap screws. I need them for McCulloch head and rod cap application. Does McMaster-Carr carry them?
ted johnson » Mon Dec 27, 2010 4:05 pm
Hillman fasteners is always a good on-line source. Ordinary black oxide steel 180KSI socket head cap screws are fine for head bolts. McMaster Carr's part No. for the 1 3/8" long is 91251A250. For rod bolts, the McCulloch spline head bolts are fine. You can find them from REAR members, and on eBay at times. You'll need the special wrench. If you go for overkill, Dave Bonbright has 310KSI super rod screws, but be aware that they'll cost you. I used them in my modified W.B. 610's, and I have them in my Mc101. If you want to use them in a Mac, Dave can shorten them properly for you. Great insurance.
Dave Bonbright
West Bend 610/820 guru
Enginemasters
557 Este-Madera Dr.
Sonoma, CA 95476
P.O. Box 14,
Vineburg, CA 95487
(707)938-8122
powerbee1@aol.com
Good hunting. Ted
Bill Hermsted » Thu Dec 30, 2010 10:51 am
I just bought six spline drive 10-32 capscrews from GEM. They were $ 3 apiece, but a cheap insurance policy since they should never be reused.
Hope you had a nice Christmas and have a happy New Year!
bill
Bob Towarnicki » Thu Dec 30, 2010 1:37 pm
Comet still lists rod bolts for $1.00 each under "McCulloch Miscellaneous Parts" in their online store.
Bob
ted johnson » Thu Dec 30, 2010 3:35 pm
Bob, the only downside to the ones CKS has is that they're not the 210KSI splined bolts, just regular socket heads. TJ
Scott Kneisel » Thu Dec 30, 2010 3:53 pm
Yes, I bought a pile of the Comet screws thinking I got a great deal however, they turned out to be regular Grade 8 alloy screws. I ended up paying a buck each for 20cent screws. I called them and talked to someone from the engine shop and they told me that they agreed that they were regular alloy screws but the length was special. OK, that is true. They also told me that they have been using those screws on every Mc9x engine they have built over the years and have never had a failure, they simply change them each time they take the rod apart. That got me thinking about the special rod bolts and are they really needed. I still like to use bolts that have a higher tensile strength than standard alloy bolts so I started looking around and found that Holochrome bolts as well as Unbreako bolts do have about a 10,000L better tensile strength and thay are not as pricy as 101 bolts so I have been using them in all my engines up to Mc91. If I build a modified engine or a 101 I use the 101 screws just to be sure. I have torque tested the Unbreako(UK) and FKE bolts from Tiawan and they start to yield at 120-130inLb so torquing then to 95-100in-lb is plenty safe. I personally use the FKE bolts and have had great luck with them. I also replace them each time I take the rod apart but they are cheap enough that it isn't a problem. I do have to shorten the 3/4" screws but that is real easy.
That is my 2 cents.
The Unbreako and Holochrome bolts are available at McMaster Carr and I think they are about 50 cents apice. The FKE bolts are harder to find, I bought a couple boxes of 100ea so I have plenty but the supplier I bought them from has changed brands so I can't say where to get them at this time.
That is my 2 cents
Scott
ted johnson » Thu Dec 30, 2010 5:56 pm
Scott, I've occasionally gotten Unbrako screws from McMaster Carr, but most of the time they supply another brand, such as Kerr. These other brands are good screws, but have a 180KSI tensile strength as compared to the 190KSI tensile of Unbrako. Some of the hardware I've gotten from McMaster has even been Chinese. I refuse to take a chance on Chinese hardware in high stress situations after the problems NASA has had with Chinese screws not meeting the MS/NAS/AN standards. If you know of a way to ensure that you get Unbrako brand, please share, as I'd surely like to use them!
BTW, on the getting crankshaft seals from McMaster, I ordered 3 PTO seals for the Mc7's, and they came in yesterday. Lo and Behold-they were SKF brand. I was really pleased. Since it was you who suggested McMaster for the seals, thank you very kindly!![[Image: icon_e_smile.gif]](http://rearenginekarts.com/phpbb3/images/smilies/icon_e_smile.gif)
TJ
Scott Kneisel » Thu Dec 30, 2010 6:23 pm
TED,
I got the supplier mixed up.
It is MSC direct that gives 4 options of what brand.
Import, Made in USA, Holokhrome and Unbrako
Try this link but if it doesn't work go to the MSC direct website and they are on page 1904 of the catalog.
Give this a try.
http://www1.mscdirect.com/CGI/NNPDFF?PM ... T4TP=*LTIP
10-32 x 3/4" Unbrakos are $20.75 per 100. Even cheaper than I thought. I think I'll buy a box!!
Good luck,
Scott
by Bob Towarnicki » Thu Dec 30, 2010 6:55 pm
Grainger sells Unbrako 10-32 5/8" length.
http://www.grainger.com/Grainger/UNBRAK ... Pid=search
Bob
ted johnson » Thu Dec 30, 2010 7:43 pm
Thanks for the two sources, guys. I added them to my "resources" wordfile. I've used Grainger many times in the past, even in the Lab's satellites and ground equipment. I noticed Grainger is a tiny bit cheaper than MSC, though shipping costs may make up the difference. I will continue using the spline-head screws for Mac rod screws, but Unbrako is great for ordinary use. TJ
Scott Kneisel » Thu Dec 30, 2010 7:54 pm
There are several ways to look at it but you can never go wrong using the 101 spline screws, maybe the $4ea price is worth the insurance against bolt breakage and I have heard that some builders use the spline bolts more than once and have not had a problem.
It is kind of funny, back in the day my dad and I re-used the rod bolts over and over and never had one break. We just didn't know any better. Maybe we were lucky.
worth reading.
it's hard to believe it was eight years ago this info was posted.
time flies.
heres the original post on Rear in case the links don't work here.
mcculloch rod bolt post 2010
i pasted the post below and the links still seem to work here
Howard ochocke » Mon Dec 27, 2010 1:00 pm
Who is a good source for small quatities of rolled-thread cap screws. I need them for McCulloch head and rod cap application. Does McMaster-Carr carry them?
ted johnson » Mon Dec 27, 2010 4:05 pm
Hillman fasteners is always a good on-line source. Ordinary black oxide steel 180KSI socket head cap screws are fine for head bolts. McMaster Carr's part No. for the 1 3/8" long is 91251A250. For rod bolts, the McCulloch spline head bolts are fine. You can find them from REAR members, and on eBay at times. You'll need the special wrench. If you go for overkill, Dave Bonbright has 310KSI super rod screws, but be aware that they'll cost you. I used them in my modified W.B. 610's, and I have them in my Mc101. If you want to use them in a Mac, Dave can shorten them properly for you. Great insurance.
Dave Bonbright
West Bend 610/820 guru
Enginemasters
557 Este-Madera Dr.
Sonoma, CA 95476
P.O. Box 14,
Vineburg, CA 95487
(707)938-8122
powerbee1@aol.com
Good hunting. Ted
Bill Hermsted » Thu Dec 30, 2010 10:51 am
I just bought six spline drive 10-32 capscrews from GEM. They were $ 3 apiece, but a cheap insurance policy since they should never be reused.
Hope you had a nice Christmas and have a happy New Year!
bill
Bob Towarnicki » Thu Dec 30, 2010 1:37 pm
Comet still lists rod bolts for $1.00 each under "McCulloch Miscellaneous Parts" in their online store.
Bob
ted johnson » Thu Dec 30, 2010 3:35 pm
Bob, the only downside to the ones CKS has is that they're not the 210KSI splined bolts, just regular socket heads. TJ
Scott Kneisel » Thu Dec 30, 2010 3:53 pm
Yes, I bought a pile of the Comet screws thinking I got a great deal however, they turned out to be regular Grade 8 alloy screws. I ended up paying a buck each for 20cent screws. I called them and talked to someone from the engine shop and they told me that they agreed that they were regular alloy screws but the length was special. OK, that is true. They also told me that they have been using those screws on every Mc9x engine they have built over the years and have never had a failure, they simply change them each time they take the rod apart. That got me thinking about the special rod bolts and are they really needed. I still like to use bolts that have a higher tensile strength than standard alloy bolts so I started looking around and found that Holochrome bolts as well as Unbreako bolts do have about a 10,000L better tensile strength and thay are not as pricy as 101 bolts so I have been using them in all my engines up to Mc91. If I build a modified engine or a 101 I use the 101 screws just to be sure. I have torque tested the Unbreako(UK) and FKE bolts from Tiawan and they start to yield at 120-130inLb so torquing then to 95-100in-lb is plenty safe. I personally use the FKE bolts and have had great luck with them. I also replace them each time I take the rod apart but they are cheap enough that it isn't a problem. I do have to shorten the 3/4" screws but that is real easy.
That is my 2 cents.
The Unbreako and Holochrome bolts are available at McMaster Carr and I think they are about 50 cents apice. The FKE bolts are harder to find, I bought a couple boxes of 100ea so I have plenty but the supplier I bought them from has changed brands so I can't say where to get them at this time.
That is my 2 cents
Scott
ted johnson » Thu Dec 30, 2010 5:56 pm
Scott, I've occasionally gotten Unbrako screws from McMaster Carr, but most of the time they supply another brand, such as Kerr. These other brands are good screws, but have a 180KSI tensile strength as compared to the 190KSI tensile of Unbrako. Some of the hardware I've gotten from McMaster has even been Chinese. I refuse to take a chance on Chinese hardware in high stress situations after the problems NASA has had with Chinese screws not meeting the MS/NAS/AN standards. If you know of a way to ensure that you get Unbrako brand, please share, as I'd surely like to use them!
BTW, on the getting crankshaft seals from McMaster, I ordered 3 PTO seals for the Mc7's, and they came in yesterday. Lo and Behold-they were SKF brand. I was really pleased. Since it was you who suggested McMaster for the seals, thank you very kindly!
TJScott Kneisel » Thu Dec 30, 2010 6:23 pm
TED,
I got the supplier mixed up.
It is MSC direct that gives 4 options of what brand.
Import, Made in USA, Holokhrome and Unbrako
Try this link but if it doesn't work go to the MSC direct website and they are on page 1904 of the catalog.
Give this a try.
http://www1.mscdirect.com/CGI/NNPDFF?PM ... T4TP=*LTIP
10-32 x 3/4" Unbrakos are $20.75 per 100. Even cheaper than I thought. I think I'll buy a box!!
Good luck,
Scott
by Bob Towarnicki » Thu Dec 30, 2010 6:55 pm
Grainger sells Unbrako 10-32 5/8" length.
http://www.grainger.com/Grainger/UNBRAK ... Pid=search
Bob
ted johnson » Thu Dec 30, 2010 7:43 pm
Thanks for the two sources, guys. I added them to my "resources" wordfile. I've used Grainger many times in the past, even in the Lab's satellites and ground equipment. I noticed Grainger is a tiny bit cheaper than MSC, though shipping costs may make up the difference. I will continue using the spline-head screws for Mac rod screws, but Unbrako is great for ordinary use. TJ
Scott Kneisel » Thu Dec 30, 2010 7:54 pm
There are several ways to look at it but you can never go wrong using the 101 spline screws, maybe the $4ea price is worth the insurance against bolt breakage and I have heard that some builders use the spline bolts more than once and have not had a problem.
It is kind of funny, back in the day my dad and I re-used the rod bolts over and over and never had one break. We just didn't know any better. Maybe we were lucky.
Dave L.