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I ran my newly overhauled ’34 V12 engine for a short time before having to tear it down gain due to a error in align boring the main bearings. Upon tear down I noticed that no lubrication was getting to the timing chain and gears. I also see that there was a hole in the top of the timing cover that had been brazed up at some time. I wondered if this was for an external oiling line for the timing gears and chain. Does anybody have any knowledge of the reason for the lack of oiling, how it is supposed to oil, or how to fix this problem?
Inadequate chain oiling is well known to Pierce 12 owners. Seagrave engines did have an external oil line added. Seagrave ran a copper line from the frontmost plug in the rightside oil gallery to the top of the chain cover. The 1/4″ elbow at the cover was plugged with solder and drilled to allow only a drip feed to the chain. There is another difference, too. The Pierce pressure control valve in the oil pump is drilled (#52 drill) to allow some circulation thru the pump. When Seagrave fed some oil off to the chain cover, they blocked this hole with a ball bearing (and used a shorter softer control spring). I suspect they did this to ensure that the additional bypass flow would not reduce oil pressure to the engine bearings when idling at normal operating temperature. Pierce 12’s idle at very low oil pressure when hot. I used Seagrave fittings on my 1703 engine and it seems to work well (no road miles yet, however).
I ran the external oil line on my v-12 and I can tell you ANY Pierce needs the extra lubrication. If you run the oil line you must install a modern seal, or the cover WILL LEAK lots of oil. John Cislak makes covers with the conversion done on the seal, and oil lines, fittings, and a correct meetered oil dump. You must not put too much oil on the chain or you can get lifter tick at idle. Pierce V-12 pressure is fine on a good engine, my car holds 20 lbs at idle on a hot day no problem. Factory timing chain lubrication was done as a bypass or dump from the end of the cam. Be sure also you have a correct oil slinger and shield installed as they are often missing. If you need photos, just ask and I will post them. If you didn’t make new cam bearings you are going to have trouble. Ed
Sorry to hear that terry, Now I am nervous as I have not driven my 33 v-12 more than a hundred miles on any one trip. Everyone says how quite my engine is, but no one out here has ever seen a Pierce 12. Ed, could you post photos of your 12? Just got a new computer as my old one had problems. Now I can e-mail again. Doug Vogel
I didn’t get a chance to get photos, and I am on the way out the door to Hershey. I will post them when I get back. Hope to see you there, Ed
Ed, in your 9/30/11 post above, you say that ….”you must not put too much oil on the chain, or you can get lifter tick at idle”. Could you elaborate on that comment? Does too much chain oil flow starve the lifter gallery? or??
Bob