Pulled the old cam shaft to replace with TA hydraulic flat tappet. The journals are 0.0015" larger diameter than the stock cam, and it is pretty tight fit. Anyone else have this issue, or know reasonable fix? I think the fit issue is significantly impacted by replacing the front cam bearing with TA-style steel bearing. That thing was a bear to install (in car).
TA 206/206 cam very tight in stock long block
- Thread starter krazy86t
- Start date
- Joined
- May 28, 2001
Installing the ft brg from the ft, can cause alignment issues. Check the ID of the ft brg vs the cam OD??
Without access to inner bearing journals on the block, I couldn't use a standard cam bearing install tool to center the replacement bearing. I made a driver from a Delrin-sleeved chunk of aluminum that was turned down to diameter that slip-fit into the new bearing. The driver was centered on the block using a piece of aluminum that was inserted on other side of block and connected with all-thread - although better than nothing, this did not lead to good alignment control of the new bearing. Bearing finished at 0.125" from front thrust surface, but it went in rocking around. Probably should have pulled the engine
I made a driver out of steel years ago and I use a dead blow hammer to drive it in. I've never had a problem. The bearing has enough of a lead to get it started square. It's possible the aluminum piece wasn't sitting flat and was cocking the bearing as it went in
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I put another bearing into the block with the driver tool I made with aluminum and delrin sleeve. This time I was careful to make sure the bearing didn't get off angle by measuring the outer edge distance from the block thrust surface. The bearing ID starts out at 1.790, and compresses to 1.787 when press fit into the block. I don't recall the OD of the bearing and ID of the block, I think bearing is approx. 0.003 oversized for the press fit. (I measured this because I considered cryo cooling the bearing with LN2 for easier slip fit, but it won't shrink enough at LN2 temp to fit through block ID)
The old cam goes into the block with the tight front bearing, but the TA cam won't fit through the 2nd journal because bearing is too tight. The old camshaft has journal OD = 1.7845, TA is 1.7865.
Are all of these numbers reasonable, or is something off?
The old cam goes into the block with the tight front bearing, but the TA cam won't fit through the 2nd journal because bearing is too tight. The old camshaft has journal OD = 1.7845, TA is 1.7865.
Are all of these numbers reasonable, or is something off?
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I've seen engine rebuilders ream tight bearings by cutting a groove into an old camshaft, but i've only seen this done on babbet-style bearings. Didn't know if it could be used for harder aluminum or alloy bearings. This Hot Rod article recommends the procedure for Clevite aluminum or alloy bearings.
http://www.hotrod.com/how-to/additional-how-to/0411rc-cam-bearing-installation/
http://www.hotrod.com/how-to/additional-how-to/0411rc-cam-bearing-installation/
