rongeur
04-08-2016, 03:08 PM
I am looking for some discussion regarding the 1.8t oil pump and it's components. I am in the middle of building a spare engine that had a balance shaft oil pump failure and instead of repeating the same risk of failure, I opted to try the 1.8T oil pump conversion for cost and simplicity sake. I went with the USP kit instead of building my own and had it delivered to the machine shop to install along side the rest of the internal machining. I finally received my engine back from the machine shop and the machinist felt that the oil pump would better be served shimmed using the intermediate plate from the original pump to take out the slack in the 1.8T oil pump chain and thus eliminate the need for the chain tensioner. I had him drill and tap the hole for the tensioner should I decide to not use the shim and stay OEM design (to the 1.8t pump that is). Pictures of the eliminated tensioner and machined intermediate plate are below.
https://farm2.staticflickr.com/1552/26314359005_b99a4d13c1_c.jpg
https://farm2.staticflickr.com/1630/26288413746_77c63a0341_c.jpg
The machinist I worked with was previously not available to the public and was contracted with high end engines for rebuilds (Ferrari, race engines, formula one etc etc). His take on the OEM tensioner is that is it a piece of s*** and just one more thing to fail as it is a bad design. I admit, I agree with his reasoning. There are many people who had complained about failing tensioners and exploding into plastic bits in the sump.
I am looking for some other educated opinons regarding race engines and chain tensioners and what the risks I am running not using one. I am cautious because I can't find much information in regards to other examples of eliminated chain tensioners. As it is now, the play in the chain is 1-2mm max and I cant imagine it skipping, especially once everything gets to running temps. When I removed the intermediate plate, the tensioner sits as most pictures online show, but the chain is pretty loose to the point if the tensioner fails, that chain would start smacking front seal and imminently fail if the plastic chunks don't starve the oil feeder first.
https://farm2.staticflickr.com/1552/26314359005_b99a4d13c1_c.jpg
https://farm2.staticflickr.com/1630/26288413746_77c63a0341_c.jpg
The machinist I worked with was previously not available to the public and was contracted with high end engines for rebuilds (Ferrari, race engines, formula one etc etc). His take on the OEM tensioner is that is it a piece of s*** and just one more thing to fail as it is a bad design. I admit, I agree with his reasoning. There are many people who had complained about failing tensioners and exploding into plastic bits in the sump.
I am looking for some other educated opinons regarding race engines and chain tensioners and what the risks I am running not using one. I am cautious because I can't find much information in regards to other examples of eliminated chain tensioners. As it is now, the play in the chain is 1-2mm max and I cant imagine it skipping, especially once everything gets to running temps. When I removed the intermediate plate, the tensioner sits as most pictures online show, but the chain is pretty loose to the point if the tensioner fails, that chain would start smacking front seal and imminently fail if the plastic chunks don't starve the oil feeder first.