JIMS 120 RELIABILITY

[Mike]

Mike , we have an appointment to have a phone conversation on this Tuesday.
I was in your shop about 2 months ago and we were talking about you building a 120" Jim's /HD engine for my bike. I have a 1999 Twin Cam that now has the big bore kit, S&S 570 geared Cams, CV 44 Carb, Screaming Eagle Heads, Roller Rocker Arms and 10.5:1 pistons. The engine has a total of 67,000 miles on it and about 30,000 miles on it since the build up. I have not had any problems at all with the engine! Jerry from Jerry's Custom Cycles here in Bend did the work for me. Jerry is a 20 year HD trained master mechanic.
I would like to know when we talk how reliable you feel this engine would be for the long haul. I don't hot rod my bike by doing burn outs, etc. but, I do like power. Most of my miles on the bike are long periods of 70 to 75 miles an hour, RPM range between 3,000 and 4,000. Rarely do I take it above 5,000. However when I do with this new engine I want the guy next to me to say Damn!!! Know what I mean? I 'm 65 years old and this Summer will probably be my last ride to Sturgis. I would to have the bike broke in by the time I take this trip. I'm also thinking about having the heads and barrels Diamond Cut and could get the bike over to you right away so you could send them out before you started the work. I would like to get an idea on what you feel would be the out the door cost on this project? Also what type of service I can expect after the work is done. Thanks for your time and I'm looking forward to talking to you on Tuesday the 24th. My phone number is 800-547-3920 Sunriver Realty. Thanks, Art

[Mike]

In theory the Jims motor should be very reliable since it is designed to be 120+ci. The key features that go to the reliability are, Timken left side crank bearings, larger thread on the cylinder studs, wider stud pattern for more stable cylinders/heads and heavier cases in key area's. Most of these features can not realistically be integrated into a stock motor when building it into a large motor.
When we talk about reliability we are really asking, "whats most likely to fail, leaving me stranded or cost a lot to repair". The higher the horsepower the more work we are asking many of the same as stock parts to do. The life of the engine is a function of how often we use those high HP capabilities. A race bike uses maximum HP nearly all the time and has an expected short life. On the other hand, when touring it may take only 40 HP to keep us going down the road at 70 MPH. In this case the motor is working no harder than it would be as stock (that's also why the fuel milage tends to be the same, when cruising). So use of the bike and riding style play a big part in a bike's expected life span. Another to approach the reliability question is to ask, "what's failing and are there more failures on these high output motors when compared to stock motors"? The most common engine failures we see, here at Latus, are mostly cam chain/tensioner wear, lifters, loss of ring seal (due to out of round cylinders, this does not leave you stranded) and the cam bearings on earlier models (the bearing upgrades seemed to have pretty much fixed this and that fix is normally part of any performance work). These failures do not seem to appear any more often in high performance motors than in stock motors. In maximum effort motors (150+hp) we do start to see more lifters, piston scuffing and valve spring failures but 150+ HP motors are the exception (for now). The lifter and spring failures are most likely due to the higher valve spring pressures required to be used with the cams that allow for these HP numbers. Our street motors would no normally use these pressures.
The standar jims motor, with no modifications, in a bike with Rhinehart true duals made 123HP/135TQ (without a large sample, we do not know if these numbers are typical). We offer a higher output version and should have dyno numbers by next week (this bike is injected with D&D Borezilla exhaust). The Jims 120 (black, alpha, carb) retails for $7999.00, motor assembly is 6hrs for $450.00, R&R motors is 8hrs for $600.00 with about $100.00 in additional gaskets/fluids and $275.00 for required clutch upgrades (TPP lockup and spring) for a grand total of $9424.00. We offer a buy back on your old motor (price varies on milage/condition) or you may find a buyer thus reducing the overall cost. We also recommend an oil cooler and starter ring gear upgrades be considered. Our high output version pricing is by appointment due to the large number of choices to be made. The above price is only for discussion purposes and an actual and accurate estimate can be established after our talk on the 24th.
Poeple will deffinetly say "Damn!" with one of these things in the bike!
As far as the type of service you can expect? Like everyone else, we think we are the best. But really, we do a lot of high ouput motors for customers across the country and have a great deal of experiance with them. We are also nationally known both to customers and the leaders in the performance industry. What this all means is that in the event you may need service we are more likely to have seen the problem, have the cure and the parts to correct it. We also warranty all of our work for 90 days regardless of milage. I'll be happy to talk in more detail regrading any of the above or other questions on during our visit or your welcoe to utulize this avenue as much as you like.

[diesel_lv]

I purchased a 120" in March for my 2005 FLHTC and had it installed in my brand new bike. I broke it in per Harley's instructions. I rode it to Ft. Hood, TX. While there, I had the 1000 mile service done and immediately after, the rear cylinder intake rocker arm broke. Jim's sent a new one but I was stuck with the labor. I then rode to New York and New Jersey then back home to Las Vegas. I then rode to New Mexico and back to Vegas. At just over 9000 miles, the intake valve lifter on the rear cylinder had the roller come off. This resulted in the lifter riding on the cam without the roller, causing damage to the lifter, cam, oil pump, push-rod and, without explination, the front cylinder had scoring.

I then took the bike to LVHD and they informed me that my 90 day warranty on the engine was up. I could not believe the engine only had a 90 day warranty since it is authorized by harley for Jim's to manufacture and sell thru harley. It took 2 months for Jim's to finally agree to pay for the parts to rebuild the engine. Another month for Jim's to agree to pay 500 of the labor. I then had to bite the other 1700 in labor.

Now, two months later and 2000 miles later, the engine clatters climbing hills with my girlfriend and myself at 80-85 mph in 5th gear in 60* weather. I can't believe that this engine that dyno'd at 128lb/ft torque at the tire has a problem climbing a hill. Weight to torgue ratio would be over 100lb/ft per 1000 pounds including the rider and passenger. My truck has 700lb/ft of torque and weighs over 9000 lbs. This is a lower weight to torque ratio and yet it will destroy my bike going up any hill.

What gives. Is this engine just for weekend riders and should never have been sold for anyone who plans on actually riding their bike? My riding style is very hard in town. The engine is rev limited to 6000 rpm so I dont think that it is getting over rev'd. On the highway I ride at 80-90mph for long distances. I have the SE 6spd and on flat level, its ok but on any hill and by myself I must go to 5th and sometimes 4th to avoid clattering. Of course Jim's says that it must be something other than their motor. I run Amsoil 20-50w synthetic.

Any suggestions would be greatly appreciated.

John Wilson
(702) 203-0421

[Mike]

These motors have generally proved to be very reliable. We have seen the lifter failure not only on the Jims 120's but the same lifters in other bikes have failed in the same way. We have also seen similar failure's of stock lifters. The rocker failure is more rare but we have seen that also, with the same rockers in other motors (they normally fail on the pushrod end). Your failures are more of a part failure as opposed to it being a function the 120 motor. I.E., these parts would have failed in any motor they were installed in. As "Race Only" motors, they only carry a 90 day warranty and buyers should be made aware of this. Unfortunately, it's the price and risk we pay for the performance. Having said all that, I (as you) would certainly expect the motor to have a much longer life than 12k miles. We routinely tell customers to expect 50k+ (depending on the horsepower configuration and it's use). I assume the Amsoil is "American V-twin" specific. We are experimenting with some lifters that eliminate the possibility of the type of failure you experianced but we just do not have enough run time to start recommending them.
As far as the clattering and apparent hp loss, I would recommend a base dyno run and cylinder cranking pressure test determine the condition of the motor. The torque curve plot and cyl pressure can tell us a lot about what may be needed. Since you have an earlier dyno chart, comparing them will help to decide if we have a mechanical problem or a tuning issue. I would not have expected any tuning changes (or need for them) as part of correcting your failures. We do know that the 6 speed tranny's often require downshifting to pull steep hills even with big motors. The overdrive feature is really intended for flat running. Both carbureted and EFI bikes will see performance losses at altitude, but carb bikes see a little more because the compensation is not as precise as EFI. I hope this al helps and that your failures are behind you.
Regards, Mike

[diesel_lv]

I have heard a lot on the lifters that come with the 120. most bad. is there a lifter that you would recomend. I have been told to go to the hydro-solids. Any other suggestion. also, the rocker arms. I have heard nothing on them except what you posted saying that the have failed in other builds. Any suggestion on the rocker arms. I did leave out one important fact. I have lowers on the bike. The new vented ones. I took them off this weekend and am riding to San Francisco in April. I will be warm here by then. I will be riding 2 up. I will see then if that makes a difference. Again, I know you havent finished the R&D on the lifters but are there any others you would recomend and rocker arms. Thanks, John

[Mike]

The Hydrosolids have been very noisy and are of the same construction of those that come in the 120 (at least as far as what's failing). For now, we are recommending H-D stock "B" lifters as we've had the least failures with these when compared to the numbers installed. The new lifters we are playing with are from Shubeck Racing (they have a web site) and are called "Roller-X". They eleminate the axle and needle rollers which are the parts that typ. fail. The roller is trapped in the lifter body with pressure fed oil into that cavity to keep the roller off contact with the body itself (just like a plain bearing rod/crank journal). They have apparently been used in Nascar and drag racing for some years now. We have been using our 30% oil pressure spring and fueling oil pumps with these to make sure we have enough pressure to prevent oil film breakthrough. Shubeck says this is not necessary but we just want to be safe. We have two bikes currently with them and are setup as solids but are available as hydraulics. Both bikes have really radical cams (.715 and .780 lift at valves) so they should be a pretty good test. Of course one has already broken a belt (right side drive, big tire) so milage testing is on hold for now. The other bike is in Sacramento and he is currently chassing down Hybusa's, we may not hear from him unless there's a failure.
Thanks, Mike

[Mike]

I forgot to mention the rockers! We did see some failures a few years ago but this appears to be history now. I did see some stuff a customer brought in that were purchased on the Internet and I refused to install them for fear of failure. They were Crane copies and just did not fit correctly. Also, know that there are some Baisley copies that are failing. Dan's are made in such a way that we have yet to see a single failure in bikes with 1.00 (yep, one inch) lift and turning 8500 rpm. I'm not going to tell how it's done and some of the other guys have not figured it out. If you do not want to go with the H-D/ Jims/ S&S/Crane then consider the Baisley's. Yes, I'm biased. You can get them with corrected geometry (they did the ground breaking research on this) and in different ratios.
Regards, Mike

[diesel_lv]

New question. You are already aware of the bike specs now, it weighs about 800 by itself and I weigh 210 and my girl weighs about 160. almost 1200 lbs alltogether. With 9.9:1 compression is it possible to avoid knocking. I am not sure if there is a VOES on this bike to retard timing when the engine is climbing a steep hill. Will race fuel, 100+ octane, help keep knocking or detonation down while climbing a 6% grade for 20+ miles while riding 2up.
Next question. I notice my oil pressure is about 25-30 while cruising and climbs to just above 32 when I get on it. At idle it is barely off the 0. Is this normal or could this have been a possible cause in the front cylinder scoring we found on the last rebuild.
Again, thanks for any info. John

[Mike]

The MAP sensor has taken over the function of the VOES. Sounds like a tuning issue. With the cams/compression you should not have knocking and should not have to run special fuel. The 6speed may be contributing and does require downshifting on steep grades (sometimes even into 4th gear since 1-5 are the same as a 5spd and these also require downshifting, even with big motors). I would be looking at ignition timing and fuel in the 20-50 MAP load area. The Jims carb. versions come with the SE race ignition tuner to allow for ignition adjustments. The LS jet and needle may also have to be adjusted.
The oil pressure seems a little low. Our LMR-002 bypass spring would increase this by 15% and is fairly easy to install. One could argue that the low pressure could cause the piston oiling jets to close earlier and thus the pistons see less cooling oil at low rpms. If you see 13lbs or more off idle then the jets will provide oil. If it takes 2500 rpm to make this pressure (at 220 deg oil temp), then we may have a problem. Oil pressure checks with a known accurate gauge at operating temps should be done. Some things to look for are scored oil pump, missing o-rings (I actually had a Jims motor with one of the web o-rings laying on the cam chest floor) sticking bypass valve or leaking/warped web plate.
Regards, Mike

[diesel_lv]

I've decided to go with the S&S IST ignition. As for the hills, I have gone down to 4th at about 4500rpm and still had knocking. I'm hoping that this ignition will allow me to run optimum advance when able and retard it when necessary. I also ordered the lifters from Schubert. They are based here in Vegas. The principal sounds very solid. That should eliminate any wory of a lifter problem again. Cheap insurance at 250 and some change for 4 lifters. Thanks for the other tips. John

[Mike]

Let me know how it works out for you!
Thanks, Mike

[diesel_lv]

What a fiasco. Module and harness come seperate. Harness is by model and year and module is use on several models and years. I get my stuff and find out that S&S and J&P both give me the wrong part number for the harness. I receive the harness for '99-'03. I call S&S and they tell me oops, wrong part for the '05. So, they overnight me the correct harness. But, without the instruction supplement. I get a fault code the wont go away and then cant read it because the '04-'05 have different code reader terminal. I had to wait till I got back from San Francisco and call S&S to find out how to read the code. finally get that and find it is intermitent or low head temp voltage. I check the resistance on the sensor and the voltage at the module. Both are within tollerance. I give the sensor wire some more slack so it wont tug when the engine rocks back and forth in the frame. So far it runs great except when the engine is hot while climbing a steep or constant grade. I have to downshift to 4th and keep rpms up and I dont get the knocking. I can live with that. Havent had a chance to have it dyno'd and wont for a-while due to harleys high prices. have to wait for the All Harley Drags in October. I'll keep you updated on the ignition pro's and cons.

Got my lifters last week and will hopelfully be puting them in in a couple weeks. I'm in the middle of remodeling my new home and it takes precidence now. I let you know how that goes.

[Mike]

Thanks for the update! If it's any consequence, we go through the same thing but also get to try explaining it all to the customer. Anxious about the lifter update!!! The home remodel does sound like a better investment hope it goes smoother. See you at the drags.
Regards, Mike

[diesel_lv]

Well, it took a-while but the lifters are in. didn't expect any difference and didn't see any. Rode to Cottonwood, AZ for the Horse Smoke-Out West. 300 miles approx from Vegas. Lots of steep grades. Rode with the bike fully dressed and with my lady on the back. Once the engine got hot from the load and the grades, I had much valvetrain noise and saw oil pressure below 32 even while cruising on straits. Don't use 6th at all anymore unless I'm cruising above 90mph (not that often).

I read an article on the Fueling Super Pump. It describes all the symptoms my engine has. Do you think that this would help my engine and if so, would it be preferable to use the Super Pump or the Racing Pump? Is the extra 100.00 neccessary? If I go this rout should I also replace the Cam Plate as recomended by Fueling?

O.K. done with the questions. Thanks for the help, John.

[Mike]

We use the Fueling pump when the oil scavenge hole in the case has been modified. When using the pump I prefer to use the plate also. We use our spring in that combo. The Race pump is not recommended and can be a pain to install without binding (closer tolerances). Fueling may have more comments on that recommendation. Without the case mod, the pump may not be as big of an improvement (still sucking through the same straw).
Thanks, Mike

[diesel_lv]

Do you have a link to the case mod and does it require splitting the cases or can it be done when the pump and plate are being replaced? Thanks for the recomendation on the pump. I don't race the engine regularly, just once a year at the AHDRA in Vegas and then some light to light stuff. I stick with the super pump and the plate. Can I order your spring on line? Thanks in advance. John

[Mike]

We do the case mods when split (actually three mods) and can clearance for cams, if needed, at same time. No link as they are propriatory. We charge $150.00 when cases are shipped to us (shipping not included). The spring can be ordered on line and is part number LMR-002 (Latus Motors Racing), $12.95 with instructions. See you in Vegas!
Mike

[diesel_lv]

Thanks for the info. It will be a while till I'm ready to take out the engine and split the cases as I hate being without this bike. Maybe when I finish the sporty I'll take the plunge. Again thanks for the info. John

[diesel_lv]

Well, installed the Feuling Oil pump and cam plate, installed the Schubeck lifters. Adjusted the lifters as I would ordinary hydraulic lifters as these did not come with instructions. Big mistake. Regular lifters have .20 travel in the plunger. Schubeck have .032 travel. Needless to say, I bent the pushrods, valves and cracked the valve guides. Between pushrods, gaskets, valves, guides, machine work and shipping it cost me over 750.00. Very costly mistake. Got everyting back in and adjusted the pushrods properly this time. Runs great, oil pressure never dropped below 35 at idle when hot and runs at around 50+ when cruising.

New problem, blows oil like crazy out the vent tubes into the intake. Oil all down the side of the bike, and when I shut it off, oil continues to drain from the air filter. It collects about a 1/4 cup in the valley between the lifter blocks. Did I install a gasket incorrectly or is the oil not draining out of the rocker boxes due to the increased volume? Any help would be greatly apprecitated. Thanks John.

Thanks for the recomendation for the machine shop up your way. They did an outstanding job. I had a little sticker shock at the cost but when I got the bill broke down, it was not unreasonable. Again, thanks.

[Mike]

I'm glad the machinist worked out! Yes, the Shubeck's require a different pushrod adjustment.
Two things come to mind as far as the oiling. First, if the o-ring between the oil pump and engine case is cut, damaged or out of place, improper scavenging will result in your problem. Two, the rocker base cover gasket or the o-ring under the supports may be out of place in improperly installed. Other possibilites could be a failed umbrella valve in the breather, a blockage of the oil pickup crossdrill in the engine case sump, or the oil pump extension from the Fueling pump to the engine case is not fully seated or has too much float, not allowing the o-rings to seal. I.E., your engine may be wetsumping, causing the carryover.
Thanks, Mike

[diesel_lv]

Ran the bike for about 10 miles hard, pulled the sump plug (bottom of case on right side) and it drained just under 1 cup. From what you told me on the phone, that would mean it is not sumping so not a problem of the oil pump itself. I also connected two hoses to the oil vents and connected them to two seperate bottles. No oil from the rear and about 2 ounces from the front. So, all the oil that I'm venting out the air filter is coming from the front cylinder. Any suggestions from hear?

[Mike]

Favouring one cylinder would indicate it's the breather assembly in the rocker housing. Could be the oring under the rocker support is missing, the umbrella valve is warped or unseated, blockage of the drain back holes in the rocker support, bad breather assy gaskets or warped breather assy. It appears oil is getting past the breather or the front head has so much oil in it that the breather cannot effectively seperate it from the vented air. In the last case, this would be a drain back problem from the head down through the cylinder to the cam chest. This can be checked by pulling the top rocker cover and cam cover. Then blowing air either up the return channel in the cam chest or doing the same from the hole next to the exh valve spring (blowing down into the cam chest) to see if it is clear.
Thanks, Mike

[diesel_lv]

Had a blocked drain hole. Used compressed air from the hole next to the ex valve spring and it cleared. Buttoned it all up and Voila, no more venting or leaks. The oil had gotten pretty dirty so I changed it 3 times today. Ran it 50 miles between each change. After the last change, I ran it pretty hard and shut it of as I was getting to my driveway. I checked the sump one last time. It had about 10 1/2 ounces in it. Is this too much and if so, will it harm the engine or am I gonna have to go back into the motor again? I have adjustable pushrods from Revolution, however, they are not the kind you can remove without removing the rocker arms. If I have to go back into the cam cover, is it possible to loosen the pushrods, use a tool to hold the lifters up an pull the cam plate out without taking the rocker covers and rocker arms off? Again, thanks for the help and advice. John

[Mike]

Glad the venting worked out. We like to see no more than 8oz after a dyno pull. You'll get more if the bike has set overnight. Wet sumping has not been known to cause damage. I've done the pushrod thing you suggest and it can be done. It's tricky getting everything back in while trying to hold everything up to clear. I've not tried it since because it seemed more difficult than the tear down. An ex mechanic of mine does it all the time, he's made clips that hold things up. Still, getting the cam set in and timed can be problemattic.
Thanks, Mike