97" build sounds like it's coming apart

[Jack Klarich]

Piston slap in front cylinder ( chinese steel trying to save money, never again) and a little rattle from both intake valves. Not much to do but tear it down and i'm not going to do that, so, i'll ride it til i wear it out, then go Axtel cylinders and Makie heads. Live and learn, i guess.

Piston slap can happen for several reasons, out of round (CHEAP) cylinders will make this worse, I would ride it til it is unbearable, I would also make it known to the builder how noisy this kit is and see if he can work a deal for you with Better parts when it is time, Too bad about Rev Tech parts, they used to be American made and pretty good Quality JMO

 

[R_W_B]

Well this has certainly been an interesting thread. I would have thought that this Indy machine shop would have mic'd the pistons and cyclinders just to make sure they were in tolerance. I always thought that was engine building 101. And if they were found bad they could have been sent back to Rev-tech before it was in your engine and your wallet. Now admittedly it would be considered above and beyond (in some circles) to do several inside cyclinder caliper readings at different positions to spot an out of round sleeve or piston. But if this is the kind of stuff folks are shipping it had better become standard procedure.

In any case I would call Rev-tech about it and tell them honestly (and calmly) just how you felt about getting the shaft on this situation if for nothing else than to hear their response. You never can tell if you word your presentation right they might help you out with at least a replacement set which you could hold till you do rebuild it again.

Addtionally I have heard stories in the past of some performance shops sending out pistons and bores with .008 clearance. Never did get the reason why. I consider it unacceptable in all facets for a street bike. When I was younger (a little after dirt came along) we used to set drag cars up like this because they would run stronger without a breakin. Kinda like a real loose running car with a 100,000 miles on it. They did in fact run a bit better but it's not going to last as long because you've removed many miles worth of wear and fast forwarded to a loose clearance that will soon be unacceptable.

 

[bodean46]

If i hadn't been in a hurry, they would have mic'd it for me, but patience was never one of my virtues. They told me yesterday to ride it for a few more miles and if it gets worse or bothers me they will re-do my cylinders with a 95" bore and fit them with new pistons for me, so we'll see what happens. Bike runs super strong with only 300 miles on it and i've kept the rpm's to under 3200, it's just makes more noise than i like right now.

 

[R_W_B]

. . . . . .They told me yesterday to ride it for a few more miles and if it gets worse or bothers me they will re-do my cylinders with a 95" bore and fit them with new pistons for me, so we'll see what happens. Bike runs super strong with only 300 miles on it and i've kept the rpm's to under 3200, it's just makes more noise than i like right now.

Thanks for the reply, that's good to hear. Maybe after everything seats it will run ok. Unless you are in a very cold climate I would run the heavier oils, that might help some

BTW I assume your valvetrain has been re-checked for pushrod clearance and locknut tight. If not I would do that. As the engine heats up it expands and if the pushrod is not adjusted into the preload enough it will run out of preload and start tapping.

 

[BUBBIE]

Thanks for the reply,**** I would run the heavier oils, that might help some

BTW I assume your valvetrain has been re-checked for pushrod clearance and locknut tight. If not I would do that. As the engine heats up it expands and if the pushrod is not adjusted into the preload enough it will run out of preload and start tapping.

And These motors do Heat & Expand. This is why I like to keep my lifter adjustment over 60% of the Lifter movement when I adjust..

signed....BUBBIE

 

[HDDon]

Thanks for the reply, that's good to hear. Maybe after everything seats it will run ok. Unless you are in a very cold climate I would run the heavier oils, that might help some

BTW I assume your valvetrain has been re-checked for pushrod clearance and locknut tight. If not I would do that. As the engine heats up it expands and if the pushrod is not adjusted into the preload enough it will run out of preload and start tapping.

With some of the new kits I've seen the piston skirts are very short. I think this is a way to lessen weight and get the engine to rev faster. Some slap can come from improper wrist pin clearence. I have never seen an engine builder worth his salt that did not check cylinders for out of round condition even if he bored them. Piston to cylinder clearence and ring gap are something that is just a matter of routine to every engine builder. Your indies offer to step you up to a bigger bore, is this using the RevTech cyl? I would be very cautious letting someone rebuild my top end that did not take the most common steps in the first place. If you do let them do the rework get a blueprint of all the measurments that they do. 1.Top Cyl bore, minimum 4 places 2. Mid Cyl bore, min 4 plc. 3. Bottom Cyl bore, same 4. Ring Gap.
5. Piston Dia, 4 plc.. I would also suggest that you have them measure the Con. rods side to side movement, and Verticle movement. No sense putting a new top end on a worn out bottom end. JMO

 

[BUBBIE]

I Believe that Short-cuts on MANY kits are giving Pistons More room to Not bind so that the cylinders Don't need to be torque-plated and $$$$$ saved in machining time...
Not un-common to hear the Slap as 6 thous clearances are NOT uncommon today (bad Kits)...
Buyer Beware is the best advice..

Harley comes "Generic Size" on their stock replacement cylinders sent out (at least to Me long ago) going 95" on my 2000 FXDS, new cylds. giving More than Needed clearances..

I bought the cylinders and HD SE pistons separate. Only to have to Exchange them go .005 Oversize on New pistons and torque-plate Hone in the over sized pistons by a few thous to FIT the Cylinders Properly HD sent out.

I would of sounded like My 441 BSA using their clearances.:rofl

That was Long ago.. And I don't Doubt it is still in the many KITS of today.(loose fits)

I have Adjusted my thinking long ago,,,, BUILD your Own Kits to fit Properly and you will save $$ in a long run.

signed....BUBBIE

 

[TQuentin1]

If i hadn't been in a hurry, they would have mic'd it for me, but patience was never one of my virtues. They told me yesterday to ride it for a few more miles and if it gets worse or bothers me they will re-do my cylinders with a 95" bore and fit them with new pistons for me, so we'll see what happens. Bike runs super strong with only 300 miles on it and i've kept the rpm's to under 3200, it's just makes more noise than i like right now.

You need to make sure you have run the engine appropriately to seat the rings. Check this out:

Harley Davidson Community

TQ

 

[R_W_B]

All good replies above but I just read back over this thread and I also noticed your lateral movement on the rockers were never fully eliminated as a possible culprit. HDDon did ask if you put new rollers in, but you did not respond on that.

You said the Indy shimmed one but not the other. I assume they did check the other one then ? Also I've read that 0.010 as small a shim you dare go. If need be, machine the ends off of the rocker shafts to stay at a .010 or more. Anything smaller and the shaft will eventually eat it up and you will find the remnants in your rockers.

I also read they HAVE to go on the correct side. Because of the directional pressure of the pushrods the forces play different on the rockers.

The following paste is courtesy of a post from a knowledgable gentleman on another forum that goes by the name of Wurk Truk.

[-Shims for exhausts should go on cam side, and intakes should go on primary side. You do NOT wish to shim until the motor is almost back together. You NEED the rocker support torqued to the head before you can have a reliable measurement to goo off of. The support flexes enough so that there IS a change in measurement. -] end paste

I've heard you can buy the shims at Jims and J&P and the old shovel shims will also work, so you could check with your local HD dealer on those.

 

[bodean46]

All good reply's. I broke it in by running 40 to 70 ten times then rode it like i normaly do. He had to shim one exhaust rocker and checked the other but it was fine. These are very short skirted pistons and he thinks that is where the problem lies, so i'll put another 500 hundred on it ( with the Spectro 20-50 dino oil that was changed at 250 miles (second change, first at 30 miles) then put the 20-50 Amsoil back in. Changing to heavier oil did nothing to quiet it down so back to synthetic and ride it with ear plugs and a full-faced helmut to hide the racket.