Like the title says, anyone just use the Briggs 9/32" guide reamer to do oversize valves on the Tec small frames? I dont know if the reamers have a different edge/blades or anything like that since the B&S is intended for the insert rather than the valve riding direct in the bored hole, and will the steel Tec guide trash the reamer? I only have the briggs reamer right now, and not sure how the tec sold ones compares. dont want to trash it or a Tec block (or R/R the guide if I damage it) if I can avoid it!
Does Briggs valve guide reamer cut the steel Tec guides clean enough??
- Thread starter markus
- Start date
not sure this really can answer your question markus or not? I have took the newer ohh heads and had to ream out the steel guides to fit briggs ss valves. I believe without looking back at my info the tecumseh stock steel guides where something like .241+ or-.001 and had to ream them out to fit a briggs steam .248 +or- .001 ballpark figure. the reamers I have are just machines reamers that are high speed steel with a 6 bladed cutting edge. now problems cutting the factory steel guides.
Most hand reamer recommendations are for a 0.005-0.008 inch increase in size. For reamers up to 1”. If you are taking more then that to get to your final dimension, another intermediate reamer would be recommended. Or drill if the amount was more.
Easy on the drilling selection, drills usually leave a much larger hole than you want. Maybe practice on a scrap block if one is handy.
Easy on the drilling selection, drills usually leave a much larger hole than you want. Maybe practice on a scrap block if one is handy.
Yea, it is engraved/marked as HSS. Its from new Briggs stock and was just a sealed bag package but the reamer is made in India. It does have the same style straight cut and blade count as the finish reamer you use to run through the guide after you install the insert on a Briggs, the one I have is from older stock, its only marked with the part number and maybe from Mowhak orginally? but running your finger over it has a more aggressive feel. Of course its a larger dia so that might be the feel difference on my finger.
I only have access to B&S 3hp parts right now, all the 5hp stuff is packed away. I did check the stem measurement and I actually get a reverse on the stem size (intake would be the only one that you could swap on those) the exhaust valve is too small on the older blocks at least the tecumseh came in with the larger number I only checked the intake not the exhaust though. I have noticed that newer built and aftermarket valves have seemed to come in with smaller stem measurements than old stock coming out of the 1970's and 1980's design boxes though.
Update and anther spin-off question to throw at you guys (@ole4 ) I had an engine come in that had to go oversize on the intake valve so I had no choice but to try the reamer and Happy to report that it it cut the Tecumseh steel insert fine, I took it slow and with caution and It left a nice finish and didn't put up a fight. So I didn't have to shell more money on more reamers that don't get used too much, Yeah!!! I was able to locate a somewhat affordable OS valve for it, so after a recutting the seat to recenter etc., all was right with the world.
Then someone sends me another engine to rebuild just last week and I start tearing down and measuring everything. Same senario, another small H block and another "hot dog down a hallway" situation on the intake guide
. Run your air filters people!!!!!
Currently the only OS valve I see available is quite a bit overpriced, so I am thinking Of countersinking a Briggs insert in this one which will allow me to retain the standard sized valve. I have one left in stock from rebuilding a bunch of Briggs & scrapheaps and they are pretty cheap so I can save the guy quite a bit of money going this route although labor would be about the same.
Question there is would there be a worry about the insert not keeping a seat if pressed into the Steel insert? On the briggs your inserting in the block itself. I can set it so there will be a lip on the bottom so the guide cant fall, but it could still ride up if for some reason it could not take a hold to the Tec guide.
Thoughts? The Briggs insert is sitting there on the left up on the deck of the block, The tapered cutter pilot is in the guide, bottomed out and wobbly (exhaust side locks in 1/4-1/2 way up the pilot......Very nice shape thankfully). I have already completed the port work and got all the edges and cast flaws taken care of as you can see, so I am ready to work on the guide and seats and move onto all the other stuff that has to be done to block to prep it for rebuild:
Then someone sends me another engine to rebuild just last week and I start tearing down and measuring everything. Same senario, another small H block and another "hot dog down a hallway" situation on the intake guide
. Run your air filters people!!!!! Currently the only OS valve I see available is quite a bit overpriced, so I am thinking Of countersinking a Briggs insert in this one which will allow me to retain the standard sized valve. I have one left in stock from rebuilding a bunch of Briggs & scrapheaps and they are pretty cheap so I can save the guy quite a bit of money going this route although labor would be about the same.
Question there is would there be a worry about the insert not keeping a seat if pressed into the Steel insert? On the briggs your inserting in the block itself. I can set it so there will be a lip on the bottom so the guide cant fall, but it could still ride up if for some reason it could not take a hold to the Tec guide.
Thoughts? The Briggs insert is sitting there on the left up on the deck of the block, The tapered cutter pilot is in the guide, bottomed out and wobbly (exhaust side locks in 1/4-1/2 way up the pilot......Very nice shape thankfully). I have already completed the port work and got all the edges and cast flaws taken care of as you can see, so I am ready to work on the guide and seats and move onto all the other stuff that has to be done to block to prep it for rebuild:
i would think if it's press in good and the motor only spinning 3600...max it shouldn't move. also would green loctite work on something like that or would the heat kill the loctite.
my question, is it possible to find a aftermarket guild that would fit in a tecumseh hole and ream to size?
if you want to do the research or call ? goodson may have it for you...goodluck markus
https://goodson.com/collections/valve-guides
my question, is it possible to find a aftermarket guild that would fit in a tecumseh hole and ream to size?
if you want to do the research or call ? goodson may have it for you...goodluck markus
https://goodson.com/collections/valve-guides
I use a miniscule amount of loctite on the them when I press them in the briggs small frames, I do a light crosshatch score in a couple of spots around the outside of the guide and seems to be fine. Not sure how the heat transfer will be in the steel guide though.
I have seen on here guys talking about using the bigger briggs guides inserted in the Tec engines, Not sure I want to attempt that with someone else's block right off, not having tried it yet.
Oh and as an FYI, according to Tecumseh's Engine RPM guide that was published in the Microfiche era (mid 1990's), their settings for the RV (recreational) 4 cycle engines were actually aimed at 3900 with a +- of 150. 3600 was more for like snowblowers etc.. Nice fellow by the name of Jake Key scanned the micro's into a PDF document recently on another site. I did a bunch of cross refencing with it compared to Known engine numbers built for mini bike/kart use specifically that are listed and they came up as such, Its interesting to see how many different RPM's ranges they were setting engines at for specific purposes out of the factory.
I have seen on here guys talking about using the bigger briggs guides inserted in the Tec engines, Not sure I want to attempt that with someone else's block right off, not having tried it yet
. Oh and as an FYI, according to Tecumseh's Engine RPM guide that was published in the Microfiche era (mid 1990's), their settings for the RV (recreational) 4 cycle engines were actually aimed at 3900 with a +- of 150. 3600 was more for like snowblowers etc.. Nice fellow by the name of Jake Key scanned the micro's into a PDF document recently on another site. I did a bunch of cross refencing with it compared to Known engine numbers built for mini bike/kart use specifically that are listed and they came up as such, Its interesting to see how many different RPM's ranges they were setting engines at for specific purposes out of the factory.
Loc tite has several products that are green. I use "green" loctite designated as 620 for mounting pressed bearings. It is rated to over 350F, but requires 500F in order to dismount bearings used with it.
For these guides, I'd use 640. Higher temp rating and designed for this purpose.
https://www.etrailer.com/Tools/Loctite/LT37424.html
I would make the assumption that a press fit guide using cured 620 would not move, since the only thrust applied to it is via an oil film. In the OldMiniBikes annals are posts where the Briggs guides were used. Can't find them now. From earlier conversations and braincell expenditures, I've always thought a Briggs guide would be an upgrade on any performance build, even if the Tecumseh aluminum guide bores were within spec.
I always enjoy your posts on restoration and improvements on these engines.
For these guides, I'd use 640. Higher temp rating and designed for this purpose.
https://www.etrailer.com/Tools/Loctite/LT37424.html
I would make the assumption that a press fit guide using cured 620 would not move, since the only thrust applied to it is via an oil film. In the OldMiniBikes annals are posts where the Briggs guides were used. Can't find them now. From earlier conversations and braincell expenditures, I've always thought a Briggs guide would be an upgrade on any performance build, even if the Tecumseh aluminum guide bores were within spec.
I always enjoy your posts on restoration and improvements on these engines.
thanks, the Tec guides are actually steel, I don’t think they had any aluminum ones, at least none I have ever seen.
This will be the first H30 I have actually rebuilt rather than just steal all the parts off of and leave at the curb for the junk guy. One thing I did learn......you can still easily find Oversize rings for them, and dirt cheap
. Will get the basics that need to be done internally, true all the mating surfaces, match port, shave the head a little, tighten up all the clearances, etc.. Pretty neat engine, its an early '70 from a cat so its black with the steel tank and Flag decaling which you can still see under that respray that's on it now. you see them in the catalog shots like that but not as much in real life since the plastic tanks were coming in that year.
I use a miniscule amount of loctite on the them when I press them in the briggs small frames, I do a light crosshatch score in a couple of spots around the outside of the guide and seems to be fine. Not sure how the heat transfer will be in the steel guide though.
I have seen on here guys talking about using the bigger briggs guides inserted in the Tec engines, Not sure I want to attempt that with someone else's block right off, not having tried it yet.
Oh and as an FYI, according to Tecumseh's Engine RPM guide that was published in the Microfiche era (mid 1990's), their settings for the RV (recreational) 4 cycle engines were actually aimed at 3900 with a +- of 150. 3600 was more for like snowblowers etc.. Nice fellow by the name of Jake Key scanned the micro's into a PDF document recently on another site. I did a bunch of cross refencing with it compared to Known engine numbers built for mini bike/kart use specifically that are listed and they came up as such, Its interesting to see how many different RPM's ranges they were setting engines at for specific purposes out of the factory.
I have seen on here guys talking about using the bigger briggs guides inserted in the Tec engines, Not sure I want to attempt that with someone else's block right off, not having tried it yet
.Oh and as an FYI, according to Tecumseh's Engine RPM guide that was published in the Microfiche era (mid 1990's), their settings for the RV (recreational) 4 cycle engines were actually aimed at 3900 with a +- of 150. 3600 was more for like snowblowers etc.. Nice fellow by the name of Jake Key scanned the micro's into a PDF document recently on another site. I did a bunch of cross refencing with it compared to Known engine numbers built for mini bike/kart use specifically that are listed and they came up as such, Its interesting to see how many different RPM's ranges they were setting engines at for specific purposes out of the factory.
does the 90's books show anything on oils? was there a thinner oil as a option too? then just a straight 30w
i have only found one cat with a steel tank on it. there kind of hard to find.
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well the printing or shoud I say microfilm is from the 90's but engine codes date back., and the literature actually predates the small frame "OHH" engines entirely, so it had nothing to do them. They go back on the list to about 1971 according to my Records, As an easy example the HS40 55388c was the Rupp roadster2/swinger trail engine starting 3rd quarter of 1971 and ran for the next 3 years until the big change to the Square shroud/steel flywheel (then it became the 55388E), That's on there. Even the next revision to the 1970 H30 I am building above is listed. Which technically I would say was probably 3rd quarter of 1970 revision change, but definitely in 1971.
And yes the rod was the same on all HS's, H35 post 1983, as well as all the similar sized verticals. They were part number 32875 and did receive some changes here and there over the years. when they designed the OHH engines in that same size frame/stroke they were trying to use what they had I would imagine to keep parts production to a minimum which is why rods, some cranks and pistons cross from the small frame OHH's over to the HS's etc... The updates to the Rod design and mounting bolts were already in place well before the the OHH engines came into play. In 1999 they finally decided to just sell the Rod with all the dipper configurations and sell is as a 32875A so it covered all the engines. So if you see a different part number in older publications for an OHH50 55 60 etc.. or actually find one in old stock, It would be 1994 (think thats when they first introduced them)-1999, its the same rod but with the OHH specific dipper. so if you are buying it to use in an HS, your not getting anything special, and your going to have reuse or buy an H/HS dipper to boot
Quote from the 1999 technicians update seminar booklet page 9 concerning the connecting rod:
Hope that helps!
yup just like this old stock 32875 rod from Before the OHH production, and the Rod out of an NOS SBH I robbed parts from, from pre OHH time as well. Like I said it was just updates to the rod design made over the years, I think they dumped the lock tab bracket and went to the serrated bolts in the middle/early 1970's. They used these rods in vertical engines too.
So usually I am held up trying to find Old stock NLA Tec parts to finish a build....this time I was that dam loctite! I went looking for the little tube of loctite green I was using and for the life of me I could not find it but I know for sure it was not the 640 like you pointed out. So off to amazon because nobody had it local. So I ordered a tube, and then it got lost in the mail! I go and check my order 2 days ago to see if its going anywhere and nothing but I notice a suggestion link for permatex equivalent. which this one shows as 1 day prime shipping.....and its cheaper!! Gotta get going on this so I ordered that tube. So, of course yesterday afternoon Both tube show up I guess I am stocked up for awhile! Gonna dig that block back out today and get working on it as I I did get all the internals and seals, and gaskets in from the various ebay vendors that have NOS pieces so I can get all that done if the guide presses in correctly. I have the guide cut already to the specified depth and all the port work I do is completed so all I have to do is get it pressed in.
At any rate heres the permatex and Loctite versions with specs off the carding if anyone cares, Lets hope this works! Thanks for the tip on the more correct product!
I went looking for the little tube of loctite green I was using and for the life of me I could not find it but I know for sure it was not the 640 like you pointed out. So off to amazon because nobody had it local. So I ordered a tube, and then it got lost in the mail! I go and check my order 2 days ago to see if its going anywhere and nothing but I notice a suggestion link for permatex equivalent. which this one shows as 1 day prime shipping.....and its cheaper!! Gotta get going on this so I ordered that tube. So, of course yesterday afternoon Both tube show up I guess I am stocked up for awhile! Gonna dig that block back out today and get working on it as I I did get all the internals and seals, and gaskets in from the various ebay vendors that have NOS pieces so I can get all that done if the guide presses in correctly. I have the guide cut already to the specified depth and all the port work I do is completed so all I have to do is get it pressed in. At any rate heres the permatex and Loctite versions with specs off the carding if anyone cares, Lets hope this works! Thanks for the tip on the more correct product!