Cam bearings
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turbofabricator
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With a flat tappet cam, use the cheapest cam bearings you can find. After-all, you're gonna be tearing it apart REAL soon anyway.
:biggrin:
All joking aside, not sure there is any advantage to a coated cam bearing. With 100 lbs. on the seat, there is not alot of load on the cam. Some guys just feel better using them, though. Kinda like peeing yourself in a dark suit..........You'll get a warm feeling, but no one will notice.
:biggrin:All joking aside, not sure there is any advantage to a coated cam bearing. With 100 lbs. on the seat, there is not alot of load on the cam. Some guys just feel better using them, though. Kinda like peeing yourself in a dark suit..........You'll get a warm feeling, but no one will notice.
With a flat tappet cam, use the cheapest cam bearings you can find. After-all, you're gonna be tearing it apart REAL soon anyway.
All joking aside, not sure there is any advantage to a coated cam bearing. With 100 lbs. on the seat, there is not alot of load on the cam. Some guys just feel better using them, though. Kinda like peeing yourself in a dark suit..........You'll get a warm feeling, but no one will notice.
I'm using 75 lb springs with an Erson 208 but have been thinking of scrapping the whole project. My theory is with light springs and my ability to make a stock cam last 45k miles, I'll be fine, but EVERYONE is telling me to stay away from the flat tappet cam.
Has anyone out there run a flat tappet aftermarket cam for 10k or more miles over the last two years? I can't afford a roller but I can't afford a new motor either. I appreciate the response none the less Ken B.
Absolutely you can do it. The last car I sold had 12k on the cam (210-205 reed, with their liters), over a period of 7 years or so. And that had the 100# springs on them. If you do go tappet make sure you use an oil that has high amounts of zinc, or add the zddp additive. All I used was valvoline vr1 racing oil, never used zddp myself. Think of a stock car they lasted 100k plus.
Good luck
Steve
Thank you. I do use ZDDP and hopefully the light spring theory holds true. I'm doing a compression test, and if everything looks good, I'm proceeding as I believe my otherwise stock 109 will last quite a while yet while I save for a new billet cap and rotating assembly build...and a roller. If current engine can last with new cam until 100k, I'll be please. 65k now. I'm installing with Zpaste and using zddp additive. Unless Erson makes a bad cam, I hope I'm fine.
turbofabricator
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The Erson cams have a slow ramp speed (good for longevity) and I use to use them all the time. It wil be fine if you break it in correctly and use an additive.
Speaking of that, what is your recommended procedure? I've heard several different ones, and I'll be using zpaste instead of the lube that came with the cam.
turbofabricator
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I start the engine, immediately bring RPM up to 1800-2K (use a pice of cardbord, varying thickness, between the throttle and stop to hold it at that RPM) look for leaks, listen for issues. After 20 minutes, and SWEATING because it'll look like the heades are gonna MELT off the car. (YES, they WILL be cherry red, almost white which is normal, don;t shut it off) Drain oil, pull filter and cut it open (use a putty knife and a hammer to cut it apart, right below the top of it) check for metal debris, there will be some, but shouldn't be alot. Tear the pleats off of the assembly and pull them apart like an accordian. Use a BRIGHT light to look in the pleate valleys to look for debris. Install new filter, new oil (with ZDDP) and start it up and let it warm up. Once up to operating temp, put in gear, stand on brakes, slowly bring the RPM up so the boost gauge starts to climb to about 3-5 psi. Then SLAM the throttle open. You are now ready to race the car. No further break-in is required. If anyone tells you differently, I would be afraid of their machine work/assembly. Nothing is "touching" in an engine except the rings to the cylinder wall, (that's why you slam the boost to them-to break them in.) and the lifter to cam interface. Timing chain links touch, but they are well lubed. Everything else is riding on a layer of oil, IF the machinework was done right. If not, then it is hurt on start-up.
GARY HARVEY
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coatings
Clearance isn't effected.
The only negative is expense.
The front bearing is under designed (overloaded), coating does help.
Clearance isn't effected.
The only negative is expense.
The front bearing is under designed (overloaded), coating does help.
There shouldn't be any machining necessary with just new cam and cam bearings right? And I've been thinking of the dual groove coated cam bearings from T/A performance, but I'm always hesitant to stray away from stock parts...their explination of the benefits make sense to me though...any thoughts?
GARY HARVEY
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- 444
Good move.
No, they do not need any clearance mods.
I don't remember which product TA uses (at one time PolyDyn used to be TAs bearing vendor). If the bearing has a black coating, wipe em' off and stuff em' in the block (+note: the oil grove in the side of the front bearing).
Some builders like to use fine Scotch Brite and lightly scuff (in the direction of rotation) the coating, only to knock off the surface finish.
If they are gray, locate the finest Scotch Brite made/available and give them a light scrub/swipe (in the direction of rotation). Then again if you have access to a safety wire manf., locate some sizing material tailings (sp)(looks like angle hair and is excellent for prepping Moly coated bearings) and give the bearings a swipe (again in the direction of wear).
Don't forget to pre-lube the engine with the oil pump before starting.. and DO NOT IDLE THE MOTOR AT START-UP/SLING THAT OIL...!
Good Decision BTW!1
No, they do not need any clearance mods.
I don't remember which product TA uses (at one time PolyDyn used to be TAs bearing vendor). If the bearing has a black coating, wipe em' off and stuff em' in the block (+note: the oil grove in the side of the front bearing).
Some builders like to use fine Scotch Brite and lightly scuff (in the direction of rotation) the coating, only to knock off the surface finish.
If they are gray, locate the finest Scotch Brite made/available and give them a light scrub/swipe (in the direction of rotation). Then again if you have access to a safety wire manf., locate some sizing material tailings (sp)(looks like angle hair and is excellent for prepping Moly coated bearings) and give the bearings a swipe (again in the direction of wear).
Don't forget to pre-lube the engine with the oil pump before starting.. and DO NOT IDLE THE MOTOR AT START-UP/SLING THAT OIL...!
Good Decision BTW!1
Thank you very much. Thanks to everyone for all the help. I'm starting on it Thursday and am hoping to have everything race ready Sunday night. Opening weekend the following weekend here...ttyl.
I have been using the coated grooved bearings in my TA block for a few years and have pounded this engine. The last time I checked everything looked extremely good. I have a valve spring that has 270 seat pressure and a roller cam. I also use a very high grade racing oil (the car is only used for racing). I also like the grove bearing because it gives you more of a window in the placement of the bearing in the block. The down side is the cost.
Jeff
Thanks. I went with the uncoated for my stock build but they are still the hardened, dual-groove and I've heard other good things about them as well. Appreciate the input.
