Hamilton 4bt cam issue

superdutyfarmer

superdutyfarmer

New member
Joined
Sep 21, 2008
Messages
401
Looking for some info on guys running a Hamilton cam in a 4bt.
Hamilton has always been the cummins cam to use. Lots of them out there and few problems I ever heard of. So when I built my 4bt I decided to go Hamilton direction. 188/220 cam, beehive springs, locks/keepers, pushrods the whole deal. When I built the engine the machine shop messed up the pistons and ended up cutting them too much and lowering the compression more than I desired. I ran it for a year working bugs out and playing with it maybe 2k miles and that's generous didn't do a ton of driving it on street. No idea on drag passes maybe 50-100.
I pulled the engine to freshen it up and put regular marine pistons in it and when I pulled it apart I found the cam gear walking off the nose of the cam. My fault due to cam not being tapped for retainer I didn't not do anything to prevent it. I sent cam, head, a set of rods out to enterprise and they send me pictures of #2 cam lobe starting to pit on the obc. I changed oil 3x and used a good zinc additive with every oil change as instructed to. I called Hamilton and they said they garuntee nothing with their camshafts and it must have been something I did.
Anybody else have issues with low miles on cams and them starting to pit? I did put brand new 24v cummins tappets in with cam

I am trying to get pieces to put engine back together but now i don't know what to do about a camshaft. $550 every year to put a cam in? Are others lasting with no issues??
 
Did the engine run at idle speed alot during the first hour of run time.
 
Not a whole lot, fired it on the stand to get the timing right and ran it up in rpm for the Break in procedure as they describe in the instructions
 
Rather than changing pistons, decking the head to reduce valve depth and therefore increase compression and low lift flow, would have been the way to go.
 
My Hamilton was junk after 20K miles. Purely due to my own stupidity though. After a long talk with Eric from No Limit I quickly learned the importance of break-in procedure, choice of oil and tappet shape and hardness... It may be worth your time to call Hamilton and run through his break-in recommendation.
 
Last edited:
Pistons were supposed to have been cut .010 and had .080 valve reliefs cut. They had mixed up them numbers at machine shop I used. I was not letting the pistons like that. Seems dumb to cut a block and increase compression instead of just putting a $450 set of pistons in it. Maybe I'm missing something.

I'm concerned due to when I called Hamilton they had all kinds of excuses all over the place instead of sitting down and talking me through it. Had they explained to me in a calm fashion maybe that I did something wrong in break in procedure or that the issue can be prevented I would have gave them a card number and bought another cam. They left me with a lot of blame, no explanation, and basically told me there are no garuntees in aftermarket parts. I did not call with intentions of pointing fingers nor am I here to blame them for making junk cams. I'm looking for options and answers to fix the problem.

I looked up and I can get a marine application 4bt cam for a little over $400 am I better to go that route?
 
You can try Colt Cams, I personally have never dealt with him, but I have heard good things.
 
superdutyfarmer said:
Seems dumb to cut a block and increase compression instead of just putting a $450 set of pistons in it. Maybe I'm missing something.
Click to expand...

Head, not the block, and unshrouding the valves is worth quite a bit. You would actually end up with higher compression than you will have with pistons with the correct depth of cut.
 
Head was sent out for port and polishing, wish I knew more about this beforehand. I'm inly a rookie engine builder definitely don't claim to know everything.
 
All I run is colt cams, Geoff is a good dude to call and bounce stuff off of him, makes a great product as well in my opinion and if I am not mistaken that is where Zack got his start in the business? and he grinds all of his own stuff.
 
Teamfreeman04 said:
All I run is colt cams, Geoff is a good dude to call and bounce stuff off of him, makes a great product as well in my opinion and if I am not mistaken that is where Zack got his start in the business? and he grinds all of his own stuff.
Click to expand...

Geoff is a smart cookie. I ran his cam way back in the day going through Piers. That was 2003-2006!

Jim
 
Colt grinds their own cams and has lifters made with correct taper so they will spin. Colt used to grind all of Hamilton's cams when he was Hamilton Diesel.
 
Putting a motor back together for a friend and he ordered a cam and push rods direct from Hamilton. Kinda disappointed that only info included with the parts was a receipt and a sticker on the tube. No installation instructions, no break in info, or any kinda of information at all.

Sent from my SM-S902L using Tapatalk
 
Even though they say that they grind their own cams from their own castings I am finding holes in their story, the cam has a cummins part number on the back of it that is a general cam out of a 100-150hp 4bt, I did some searching and found a genuine cummins marine cam part number out of a 250hp engine. I think that's gonna be the route that I end up going. Talking with Brandon at enterprise we think that Hamilton reground this cam and just got too far into the finish coating causing the cam to pit
 
Last edited:
You're in good hands with the guys at Enterprise. I would say that what you and Brandon came up with is very likely the cause.
 
Just curious. What is the break in procedure for there cams? My steel cam came with no break in info. When I build engine's, I start the engine and check for leaks. Then go straight to the engine or chassis dyno and load the ever living piss out of it. Watch blow by go away to confirm ring have seated and call it a day.
 
You must log in or register to reply here.
Top