Time for me to address the 800lb Gorilla in the room.(Engine knock thread) REVIVED!

[scdmarx]

If you are looking for matched cams, why go with the 1200 cams with the extra mods needed to work in your 1100?
Is it because you're assuming they will be in better condition?

Just asking :?:

 

[joedrum]

yes dan your right .....when i say the springs are not up to the job im also saying the crude cut cams are the number one reason why ....the soring is the only part that keeps the valves down on the cam .....and while the valve is in movement the spring is the cushioner and the valve is preloaded with tension...its only at the very end of travel that it becomes nuetural or not preloaded tension ....this the biggest reason solid valve trane can get more rpm than hydralic...

ilook at a bear head today and discovered something obvious :headscratch: the springs are diffinitly wearing the heads ......shiming the heads is probably manditory to get stock valvs spring heigth because of heads wear .....if the springs are not at speck hieght from wear then the spring looses spec tension on the valvs stem...this would cause massive loss of tension at the most credical point ....the cam comes around and smacks the rocker right in the air from lack of tension in the spec valve at the neutral possition....as the situation gose on it get worst with more and more wear ......this all in the field of accumulated wear and outcome ....this reminds me of farming deals ive ran into many times in the past on running big motors at full thottle around the clock ....all weak links in the chain parts come to the top like cream in raw milk.... :mrgreen:

so i think some kind of shims .020 or so need to be used to compensate for head wear ....enven if you had new springs....with this kind of hammering it silly to think it will be just one part thats effected .... :mrgreen:

 

[scdmarx]

Say Joe, I don't understand why you say the springs are not up to the job.

Because the only explanation that makes sense for the wear pattern on the trailing ramp of the cam lobe is valve bounce, which brings us back to the spring.

If the better cams do in fact make the noise go away, eventually the weak springs will beat these cams into the same condition.

But....by attacking the noise one step at a time, at least you'll know what worked. :music:

 

[slabghost]

If you are looking for matched cams, why go with the 1200 cams with the extra mods needed to work in your 1100?
Is it because you're assuming they will be in better condition?

Just asking :?:

1200 has more torque and the cams may impart this to the 1100 motor. So far I'm hearing good things from Joe on using the 1000 cams in the 1100. I'm anxious to see how the 1200 cams affect the power curve as well.

 

[joedrum]

right on ron ....name that tune in five words or less :hihihi: :mrgreen:

 

[dan filipi]

Gerry, The shop said piston slap will make the engine sound like a diesel so something to consider on yours..

Ron, mostly out of curiosity I'd like to know how an 1100 would run with 1200 cams but also I think 1200 cams are less likely to be worn and I think we stand a better chance with them finding out if the knock is gone.
I haven't decided if I'll buy because ultimately it looks like I'll end up with having the stock cams reground, I'm thinkin to early 1000 specs which I think would cost less than $200. With 1200 cams I'd have to figure out a way to get a tach working which won't be stock.
I want to get at least one engine in my runner to the point that it's quiet and reliable. Reworking the valve train is one step in the process of many.

$42 with shipping is hard to pass up to satisfy the curiosity.
I asked the seller if these cams have ANY flat spots, edges, or any other signs wear. Waiting on an answer.

 

[dan filipi]

On another note,
I'm getting some lifter clatter running this 1200 cam that wasn't there with the 1100 cam.
Also it's running like I would compare to carbs out of sync.

With the same valve springs and rockers as before and adjusted carefully I'd think it should not clatter so I'm not sure what to think of that.

Being out of sync kinda makes sense to me since the lift and maybe duration is different between the cams.
If I have time later I'll put the gauges on it.

 

[mcgovern61]

Gerry, The shop said piston slap will make the engine sound like a diesel so something to consider on yours

Yep, haven't given up that thought yet either. Again, I cannot tell until I split the case. I do not need to do anything with that engine for now so I will patiently wait to see how your cams work out. (It is the same knock).

BTW....I seem to remember in the original thread (BC days) that you had checked bearing clearances and pistons and did not find anything out of tolerance?

 

[dan filipi]

BTW....I seem to remember in the original thread (BC days) that you had checked bearing clearances and pistons and did not find anything out of tolerance?

Thats right but the one thing I didn't check is skirt to cylinder clearance.

(Thank goodness for spell check or I'd have a lot of typos)

 

[mcgovern61]

BTW....I seem to remember in the original thread (BC days) that you had checked bearing clearances and pistons and did not find anything out of tolerance?

Thats right but the one thing I didn't check is skirt to cylinder clearance.

(Thank goodness for spell check or I'd have a lot of typos)

Which reminds me...I am going to pull the back cover from the '81 engine and check the scavaging pump.

 

[scdmarx]

Thats right but the one thing I didn't check is skirt to cylinder clearance.

That would make sort of a rattling noise. But I'm not sure how that acts on a pancake motor.

 

[dan filipi]

But I'm not sure how that acts on a pancake motor.

I think the engine design along with having a fairing which can amplify noise is part of the problems we're up against here.

If I hadn't heard the difference with my own ears I might not have believed it but the knock is definately less or completely gone from the left side now with the 1200 cam in place. I can hear some but that sounds more like noise from the right side.

I did a buy it now on those 1200 cams, waiting on a total from the seller.
He says the engine has less than 5k miles on it.
Thanks Ross for the link!

I gotta say, it's fun having you guys here to follow along with each other and as enthusiastic about all this as I am.
My brother and I used to play in the garage and I've missed that for years since he moved to AZ.

I'm thinkin the 1200 cams along with the hydraulic adjusters may bolt up to my 1100 heads.
How cool would that be, an 1100 with self adjusting lifters!

 

[joedrum]

thats cool dan but i think there an in the heads oil supply lacking in the 1100 head ....but thats just a thought not somthing i know for sure ....if you have a 1200 heads around you could check ....i will try to find out too..... :mrgreen:

it would probably be easy to look up a head job rebuild to see if there is any different oil passage in the 1200 head that feeds the hydraulics...

 

[dan filipi]

thats cool dan but i think there an in the heads oil supply lacking in the 1100 head ....but thats just a thought not somthing i know for sure ....if you have a 1200 heads around you could check ....i will try to find out too..... :mrgreen:

I took a look, your right oil delivery is different.
Oh well, it was a short dream :smilie_happy:

At any rate I'll have 2 good cams if they are what he says they are then if it doesn't work out I'll have 2 cams and rocker assemblies for sale cheap :whistling:

 

[dan filipi]

I've been measuring the cams I have and found spec for the center journal.
So far 3 cams are at the minimum spec or just .05 over.
Does this mean these center journals are done for and grinding the cam would be a waste of money?
I suppose if they can fill and grind the lobes they can do the same to the journals, right?

Just trying to figure out what needs to be done to end up with a good tight valve train.

One thing I noticed when I put the 1200 cam in was it turned much harder than the 1100 cam that came out.
Are these less worn journals the reason for that or just needs breakin?
(Note I used moly 60 as an assembly lube on everything)

 

[joedrum]

im not going to knock anything but the molly itself might make it stiff ....i havnt used it like this .....any way i dont think the carrier would hurt you if the cams were smooth......no kidding dan if i were you and there and with the parts you have at hand .....i would take those 1100 left and right 463 beat up cams you have and i would by hand go over those lobes and true them up putting them in the light to check them its teidious but not hard .....theres no way your going to to much harm by hand that would keep them from working ......then put them in your bike it will tell you all you want to know about the noise in the motor ....and then you can go from there about what to do .....thse cams look no worst than the ones i work with yours are better actualy and they ran quiet and it would cost you nothing to try this to find out about the motor....thats what id do and im sticking to it....if the noises quit in the motor then more options come to the table...... :mrgreen:

 

[dan filipi]

It's tempting Joe.
I don't think I have anything to loose considering the condition of these cams.

What would have to be done to pull this off?

 

[dan filipi]

It was baffling me where the heck the other 1000 cam went so I pulled the valve cover off my runner and WALA, there it was!

Somehow in all the head swaps I was doing a while back I must have put the head from a parts 1000 engine that was given to me.
One mystery solved.

Joe, you were asking if the 1000 cams are the 75-77 and yes they are.
The way I found out was by measuring the lift. 75-77 is 1.46, the 78-79 is 1.45

 

[scdmarx]

I've been measuring the cams I have and found spec for the center journal.
So far 3 cams are at the minimum spec or just .05 over.
Does this mean these center journals are done for and grinding the cam would be a waste of money?
I suppose if they can fill and grind the lobes they can do the same to the journals, right?

Right. I would think the journals would be easier because they are round.

I just took a peek at the manual and it's giving 0.0055" or 0.140mm for a service limit. Measureing clean, dry parts with plastigauge would probably be the easiest way to go unless you have a set of I.D. mics and are familiar with taking such measurements. Plastigauge is inexpensive at the parts store. Just tell them what size range you want to measure.

One thing I noticed when I put the 1200 cam in was it turned much harder than the 1100 cam that came out.
Are these less worn journals the reason for that or just needs breakin?
(Note I used moly 60 as an assembly lube on everything)

I'd say as long as you can turn them freely by hand with regular engine oil would be a safe shot in the dark. Better off to plastigauge, there could be tapers.

 

[joedrum]

gee dan you know what this means dont you ....unbalance is not even close ...its obvious your motor been fighting itself ....knowing like i do the huge differences in the duration of the two cams ....this is obviously the biggest problem in your bike with this added in to the mix of springs and crude cam manufacture....

let me list all the things i think on your bike

the 1000 cams will be the hardest to get to run smooth ....they have the most lift and duration of all the cams for four cylinder wings...if you want to use these cams i would think you would have to shim the springs .020 to account for wear and purchase new springs....if that is a 1000 head you put on there is a 2 1/2 cc combustion chamber difference...proably not a problem something i know so i threw it in there.....

the 1200 cams are the mildess .....and on your bike will be the easyest to get to run smooth there valve opening time is the shortest.....and less stressful you could go this way and probably get by with the springs you got .....my opinion is that your bike would gain some low end grunt and run out on top some ....with the 83 gearing this might be good ....theres no doubt that this is a logical choice on your bike given it might be hurt internaly you dont want to put in superbike cams in a wounded bike ....

as far as doing a trueing job on cams ....whatever cams you chose sould get a final hand machineing and polish before install...use a reflextive light angle and make them look good and bring plenty of pateince to the table after awhile you will see the obvious improvement start showing in the light ...i did mine right here by the computer while looking at info and working on the cams ....that flexable grinding disc work good for me ...this is no different than polishing intake ports for better flow...your polishing the lobes for smoother travel ....

you have nothing to loose by trying this on the 1100 beater cams you have or wait for the 1200 cams which are probably pretty smooth to begine with and make the most sense on your bike as i see it ...except for the fuel pump issue.....

i dont think that 1000 cams are a good for you ......if your bike was a known good motor it would my first choice but with the reservation of the 83 gearing it might be a little tall for the 1000 cams .....i would still do it to a good 83 motor...

its your call

its still my call like my eralyer post to do up the 1100 beater cams by hand the best i could put them in a see what happens to the noise thats my choice still and im sticking to it.... :mrgreen: