Cam bearings

Webers, Cam selection and Ignition upgrades.

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Toyota1515
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Joined: Fri Aug 09, 2013 2:59 am

Re: Cam bearings

Post by Toyota1515 »

KE20Rally wrote:So far the cam bearings that come in my blocks have been in good condition, my machinist recommended to leave the old ones in the block as they can be a pain in the butt to replace and I am assuming that is why you are having the clearancing issue. http://www.zapsrat.com.au/ )

Pete
Yeap agree 100%, i always try to keep the OEM ones as much as i can, trust me i learn the hard way, cuz is a PITA to massage em to specs then clean all the shit again!
SF5 FOZZY
tavirace
Posts: 10
Joined: Wed Jul 24, 2013 12:54 am
Location: Ontario Canada

Re: Cam bearings

Post by tavirace »

Just curious if you have a source or part number for the bronze distributor gears, good info to know,Thanks
Rodger
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Re: Cam bearings

Post by Rodger »

Gotta love this.

I too have destroyed three cams over the years since the mid 1980s. 1740 2T with TRD oil pump and all the TRD stuff from the catalog at the time. The first TRD cam ran well for several seasons without issue 8500 most often. Laid off motorsport until about 1992 when I went to do my racing licence here in Aus. Finished the day using my tow vehicle as I destroyed the cam and dizzy in about 100km. Could not figure it out at all. Two years later I had rebuilt using a reprofiled stock cam of mild values, took the car out, it lasted three laps. Same issue. Rebuilt with another cam this time a copy of the TRD, lasted not much longer.
Then I read about the oil and how it had no ZDDP as manufactures were changing blends to suit modern motors.
So I changed to an oil that had the aditive put back in and is sold for old school motors, then figured out and installed the same oil squirter system, except I took it off the spare port near to my oil switch.
The motor then sat unloved for 10 odd years as a result of these gear falures and I never tried out the squirter in anger.

Brining the story up to date I now have a big cam from BRD and yet to have it really running to try out what is going on as the motor is now in a show Celica. My next step is to get the bronze dizzy gear made up and I did look at the gear meshing and thought it was not the best so another thing to check. Imperial gear on the BRD and Metric on the dizzy??

Anyone confirm the specs of the gears ?

My solution to it all if I had made the time and effort was to ditch the oil pump and dizzy and run a dry sump and crank trigger, or dry sump and run a dizzy off the end of the cam.

The clubman boys back in the 70s/80s using 3K motors used to run an oil pump off the end of the cam, bolted to a modified timing cover and I thought at the time it was a great idea.
Regards
Rodger
Lover of the Solex/Mikuni sound
http://www.rmcarburetors.net
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toyotero2dend
Posts: 495
Joined: Sat Jun 22, 2013 4:54 am
Location: New York

Re: Cam bearings

Post by toyotero2dend »

Ask the machine shop to check the cam bearings if they are good do not mess with it .... I had replace em on one of my engines and the cam wouldn't turn freely so had to spend hours with sand paper n oil on the cam to make it fit..
Tate Quieto
KE20Rally
Posts: 15
Joined: Tue Oct 29, 2013 11:42 pm
Location: Perth, Western Australia

Re: Cam bearings

Post by KE20Rally »

Rodger wrote:
Brining the story up to date I now have a big cam from BRD and yet to have it really running to try out what is going on as the motor is now in a show Celica. My next step is to get the bronze dizzy gear made up and I did look at the gear meshing and thought it was not the best so another thing to check. Imperial gear on the BRD and Metric on the dizzy??

Anyone confirm the specs of the gears ?
I can only go on what my machinist said, he does a lot of stuff for the vintage guys so I took his word for it, the gear cut on the Schneider cam was imperial, so he cut my new gear imperial. I'm not sure if the pictures show it clearly, but you can see the wear is uneven on the cam indicating a mesh issue. To be sure, take your BRD cam and a standard dizzy gear to your machinist and ask him to cut it to suit your cam, this is what I did and the engine is still going strong.
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73GTV
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Location: Warner Robins, Ga 31088

Re: Cam bearings

Post by 73GTV »

KE20Rally wrote:So far the cam bearings that come in my blocks have been in good condition, my machinist recommended to leave the old ones in the block as they can be a pain in the butt to replace and I am assuming that is why you are having the clearancing issue. He has a good reputation over here so the old bearings stayed! (had a lot to do with the development of the fastest door slammers in Australia http://www.zapsrat.com.au/ )

Pete
What does he not own a cam bearing installation tool? Its a breeze with the correct tooling.
Toyota1515
Posts: 784
Joined: Fri Aug 09, 2013 2:59 am

Re: Cam bearings

Post by Toyota1515 »

73GTV wrote:
KE20Rally wrote:So far the cam bearings that come in my blocks have been in good condition, my machinist recommended to leave the old ones in the block as they can be a pain in the butt to replace and I am assuming that is why you are having the clearancing issue. He has a good reputation over here so the old bearings stayed! (had a lot to do with the development of the fastest door slammers in Australia http://www.zapsrat.com.au/ )

Pete
What does he not own a cam bearing installation tool? Its a breeze with the correct tooling.
I own a cam bearing installation tool and preferred not to change the cam bearings in a 3TC whatsoever!
SF5 FOZZY
KE20Rally
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Joined: Tue Oct 29, 2013 11:42 pm
Location: Perth, Western Australia

Re: Cam bearings

Post by KE20Rally »

73GTV wrote:
KE20Rally wrote:So far the cam bearings that come in my blocks have been in good condition, my machinist recommended to leave the old ones in the block as they can be a pain in the butt to replace and I am assuming that is why you are having the clearancing issue. He has a good reputation over here so the old bearings stayed! (had a lot to do with the development of the fastest door slammers in Australia http://www.zapsrat.com.au/ )

Pete
What does he not own a cam bearing installation tool? Its a breeze with the correct tooling.
Yes he has the tool, I guess my wording is not quite right, easy to change, issue is as discussed above the bearing clearancing issues, ie the cam has tight spots when turning by hand, you then need to work out which bearing is tight (this could be due to aftermarket manufacturing tolerances or any number of of reasons) then get in there with some 2000 paper and free it up. Maybe we are just being anal about it, but I like everything to be measured and clearances correctly when building an engine, so if the standard cam bearings are in good condition, they stay, otherwise new ones go in and out comes the wet and dry!
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73GTV
Posts: 123
Joined: Wed Jul 10, 2013 2:17 am
Location: Warner Robins, Ga 31088

Re: Cam bearings

Post by 73GTV »

KE20Rally wrote:
73GTV wrote:
KE20Rally wrote:So far the cam bearings that come in my blocks have been in good condition, my machinist recommended to leave the old ones in the block as they can be a pain in the butt to replace and I am assuming that is why you are having the clearancing issue. He has a good reputation over here so the old bearings stayed! (had a lot to do with the development of the fastest door slammers in Australia http://www.zapsrat.com.au/ )

Pete
What does he not own a cam bearing installation tool? Its a breeze with the correct tooling.
Yes he has the tool, I guess my wording is not quite right, easy to change, issue is as discussed above the bearing clearancing issues, ie the cam has tight spots when turning by hand, you then need to work out which bearing is tight (this could be due to aftermarket manufacturing tolerances or any number of of reasons) then get in there with some 2000 paper and free it up. Maybe we are just being anal about it, but I like everything to be measured and clearances correctly when building an engine, so if the standard cam bearings are in good condition, they stay, otherwise new ones go in and out comes the wet and dry!
It is your engine and you have the situation well in control. I have a different look at why I change them, That tool cost enough that I want to get some use out of it, plus like the idea of virgin bearing installed. Good luck with your build.
KE20Rally
Posts: 15
Joined: Tue Oct 29, 2013 11:42 pm
Location: Perth, Western Australia

Re: Cam bearings

Post by KE20Rally »

[/quote]
It is your engine and you have the situation well in control. I have a different look at why I change them, That tool cost enough that I want to get some use out of it, plus like the idea of virgin bearing installed. Good luck with your build.[/quote]

Fair enough reason, engine has been going strong for the last 2 seasons, way more power than I am willing to use at the moment, as I had a lay off from driving for a few years, looking at a Rolla cam next, but I need to fix the rest of the car and do a brake upgrade first!
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