THE CAMGRINDING FAQ

In October 2000 Art advised me that the cam grinding info has been updated and you can find it here. If you can't find it there, the following is an earlier version.

This faq came about after a discussion on the SabMag email list for Sabre and Magna owners. Contact Jude G Federspiel jfed@mit.edu for more information, and to subscribe to the mailing list.

At one point, we discussed having an exchange program, with a cam grinder keeping a finished set on hand, ready to ship. Customer would send a cheque to cover the re-ground cams, and another cheque as a "core charge" or security to ensure that the old cams would be returned to the grinder as quickly as possible. Similar to what is done when you go to an auto supply store for a rebuilt carburetor, you will be charged for the rebuilt carb, plus a "core charge", which is refunded when you bring the old one back to the store.

Most of the information I have learned about cam grinding, I learned from Geoff Bardal and Barry Rutherford (since retired) of Shadbolt Cams , 1713 W. 5th Ave., Vancouver, BC V6J 1P1, telephone (604)738-9505. Collectively, they have been re-grinding stock and high-performance cams for a long time.

I talked to Shadbolt Cams twice about the exchange idea, once on my nickel and once on theirs, and after talking to Geoff Bardal, we came to some conclusions:

1. Due to small differences over different years and models, the idea of having a set on hand, ready to go, probably won't work too well, as there are some minor differences. He feels that he can get most sets out in 2-3 days, especially if he has a little warning. If the cams need welding in order to rebuild them, one or two lobes aren't too bad, but if more is required, this may bring it to a week or 10 days.

2. Due to differences in material, the amount of work required varies. Some of the Magna/Sabre cams that Geoff has done have been so soft as to not register on his Rockwell(tm) hardness tester. Some, like mine, were in the correct range (25-30), and just needed regrinding. He can weld the softer ones with a special rod and a powder additive to bring them up to the correct hardness. In 1988, after the warranty from Honda started to expire and people had to pay for new ones, he spent some time with a junk set to come up with the right combination.

   If you are talking to a different grinder, find out if he can weld the lobes, and what kind of rod and powder he uses for the job. Also, ask if he can check cams for hardness. If the answers are kind of vague, or something like "they're all hard" or something like that, he doesn't check them, or doesn't care.

3. Geoff has found a couple of cams with a different profile. The stock cams have a lift of .210, and a duration of 227 degrees (intake) and 224 degrees (exhaust), while a customer brought in a set out of an oddball Sabre that had .220 lift and 227/229 duration. He tried to find out why, but didn't run into the same profile until several years later when a customer brought in a set of "special, rare European" cams out of a 1000 cc Honda which had the same profile. These cams were equipped with a timing advance mechanism, and had a different profile as well, with a "backside hump". This allows the valve to stay open longer, after the air/fuel flow has been established, allowing more in, making more power. He can grind this profile (and has, with glowing customer reports :-)) for a minimal charge. Not a large change in performance, but also no change in idle characteristics and gas mileage.

   After grinding, all camshafts must be "Parkerised(tm)". This process puts a coating on the lobes to hold the oil during initial break-in. If this is not done, the oil will not stick to the cam, greatly accelerating wear during the first few hours. After the break-in, the pores of the cast iron will have absorbed enough oil to "wet out" the surface of the lobes.

   Usually, a molybdenum disulfide (moly) grease is put on the cam to provide lubrication until the oil pump gets oil to the lobes. Do not use Lubriplate(tm), as it has been known to plug oil holes sufficiently well to prevent oil from getting through. Lubriplate(tm) is a high temperature white, lithium based grease, and works well as a permanant lube in sealed environments (gear boxes, etc.), but these same characteristics prevent it from melting and moving out of the way until very high temperatures are reached. By then, damage has occured in other, downstream, areas of the engine.

   Similarly, do not apply STP(tm) to the lobes and journals, as this may cause your clutch to slip. We have enough trouble hooking all this power to the transmission, without aggravating the problem :-)

4. When I mentioned that some of Shadbolt's potential customers were in year-round riding country, and would not like to shut their mounts down for 2-3 weeks, especially when the bike is their favourite (read: only) transportation, he sounded willing to deal with customers to make the deal as painless as possible. You just need to talk to him.

I then called Canada Customs, and discussed the border thing with them. The gentleman I talked to felt that if the package was labeled something like: "Used motorcycle camshafts, for remanufacture (or reconditioning) -Value $4.00 each X 4 = $16", they would slide thru Customs quite quickly, as they are not interested in collecting the small amount of duty that they might be worth. He estimated one day or same day through-put. This applies only to US/Canada Post, not UPS, etc. The paper work would cost more. This would only apply coming into Canada.

I then called US Customs, and after 3 people, came to the conclusion that "rebuilt or repaired" parts would probably fall under NAFTA, and have no duty attached. The Postal worker in Seattle said to label the package "Returned US Goods" Merchandise value $XXX Remanufacture value $XXX". The tariff number would be 8409.99.99.90 and the rate number would be 9802.00.50. and would fall under a "informal entry under $1250.00"

The Postie said that if there was any duty, it would be charged at a rate of 2.2%. He didn't sound very sure when I mentioned that the border clerk at Blaine had stated that they would fall under NAFTA. For the $5 duty, I don't think it would be worth the hassle of arguing with them. He said that the parcel, if dutied, would have to be picked up the nearest Post Office to the addressee, as the PO would act as Customs Broker.

At that time, I asked Trenton Schoeb trs@uab.edu to talk to people in his area, and his return follows:
< Hey, Art. Talked to US Customs over in Jacksonville re sending cams US to
< Canada.
< 1. Don't need shipper's export paperwork since value less than $2500.
< 2. Ship ordinary UPS. You are supposed to register items w/ Customs, form 4455.
< You have to take cams w/ you to Customs office for this so they can
< "inspect" them.
< 3. Return is similar process. Shipper takes cams (in case they want to
< "inspect" them again) and invoice showing value of repairs to US Customs
< office. Fill out form 7512 declaring value of repairs, required for re-entry
< to US. The 2 guys I talked to were "almost certain" it would be duty-free
< under NAFTA, but to be totally sure, a customs "import specialist" would
< have to look it up. Worst case is 2-3% duty.
< I would imagine that UPS etc. encounter situations like this frequently
< sending stuff into US and might well have some tips for streamlining the
< process.

• NOTE
  Following the experience of one of the members of the Sabre/Magna mailing list, we found out that UPS has a $25 brokerage fee to move items across the border. This was in addition to the shipping charges. This seems to be a little excessive for something that will just be rubber stamped across the border.

To add anything to this FAQ, please send comments, additions and flames to:areitsma@uniserve.com. If you have dealt with another cam grinder, and have had good results, send me their name and address, and I will start a list.

Hope this helps,
Art Reitsma