It is too soon to record your valve adjustments for trends, but do keep an eye on any that seem unusually tight or loose (more than .002 off).murphyslaw wrote:I will re check the valves tomorrow, before any more driving.
Colin
I was just going to check the valves to see if everything there is ok. Its not really for any thing other than to look under the rocker cover , and re assure my self that all is well, and to see if thee is any rogue settings developing.Amskeptic wrote:It is too soon to record your valve adjustments for trends, but do keep an eye on any that seem unusually tight or loose (more than .002 off).murphyslaw wrote:I will re check the valves tomorrow, before any more driving.
Colin
A trend is three adjustments in a row that deviate in the same direction by a noticeable amount.murphyslaw wrote:I was just going to check the valves to see if everything there is ok. Its not really for any thing other than to look under the rocker cover , and re assure my self that all is well, and to see if thee is any rogue settings developing.Amskeptic wrote:It is too soon to record your valve adjustments for trends, but do keep an eye on any that seem unusually tight or loose (more than .002 off).murphyslaw wrote:I will re check the valves tomorrow, before any more driving.
Colin
Can you tell me more about " recording valve adjustments for trends". Is there a pattern over a set mileage that will give me some information of how my engine is performing, and what type of readings that I should expect to see. Thanks
murphyslaw
No, the head studs do not stretch. The soft aluminum, however, both at the head contact surfaces and the crankcase contact surfaces, does "set" to the cylinder barrels during break-in. This makes the heads migrate closer to the centerline of the engine. Picture what happens to the rockers as their supports move in. A tenth of a millimeter in at the supports translates into two tenths of a millimeter at the valve stem due to the pushrod, whose placement never changes, because all it knows is the camshaft.midatlanticys wrote:Is it my imagination or do the headstuds *stretch* in length after X number of hot/cold cycles . . . . . . enough to warrant a retorque of the heads after 50 or 100 miles? Can this variable also figure into changes found when setting valves?
Thanks, its going great, and a nice smooth driver. The pull start on the normal alternator pulley was used by my uncle in the early 70,s, on old 6 volt beetles.midatlanticys wrote:Nice one Murph! =D> =D> Sounds good and must be fun to drive after having it open on the bench!!. I've never seen a pull start bug before; nice touch!!
Gotta love the Harp on the Irish €2 coin!
Sound about right. the 2000 rpm's for 20 is good for the cam. Murphy didn't need to do that because he just did a top end rebuild. I'd probably change the oil after the drive for the rings.jackstar wrote:Colin et. al,
I am in the process of rebuilding a 2.0l 79 FI CA Westy back to as stock as I can. I have read alot of posts as to break-in procedures both here and on the Samba. Do they differ by engine size or degree of rebuild?
As to the 20 minute at 2000 rpm initial start up, am I to assume that the bus doesnt actually go anywhere? That you simply set the rpms or hold the throttle at 2K for 20 minutes? If so, after you change the oil and filter, do you then jump in and go off for the break-in procedure of gears, throttle ups, throttle downs etc never staying at the same rpm for long but above 2000 rpms. This is done for 100 miles correct? And then onto the other mile posts?
Sorry to be so thick, but after awhile of reading a bunch of threads you start to question your own ability to remember and apply the technique. If you can guide me to the Nirvana of start-up break-in procedures I would be most grateful. Thanks.
Jack
The initial 20 minute break in is for the cam lobes and lifters. You are correct that this is a run in the driveway period, no driving. You want to get the rpm right up to 2000 after it fires. No idling at all. No higher than 2500rpm. You don't have to vary the revs just find a spot between 2000-2500rpm. If you have some oil leaks don't shut it down unless it's a gusher and you're going to lose more than half a pint or so. If you do have to shut it down before 20 minutes there is a procedure for the next attempt. After the cam break in let it sit over night or until you know the engine is stone cold and do a valve adjustment. This is where you will begin your log of valve adjustments, particularly if you are using solid lifters. Take notes of valves that need adjusting every time. It could be a sign of bad things.jackstar wrote:Colin et. al,
I am in the process of rebuilding a 2.0l 79 FI CA Westy back to as stock as I can. I have read alot of posts as to break-in procedures both here and on the Samba. Do they differ by engine size or degree of rebuild?
As to the 20 minute at 2000 rpm initial start up, am I to assume that the bus doesnt actually go anywhere? That you simply set the rpms or hold the throttle at 2K for 20 minutes? If so, after you change the oil and filter, do you then jump in and go off for the break-in procedure of gears, throttle ups, throttle downs etc never staying at the same rpm for long but above 2000 rpms. This is done for 100 miles correct? And then onto the other mile posts?
Sorry to be so thick, but after awhile of reading a bunch of threads you start to question your own ability to remember and apply the technique. If you can guide me to the Nirvana of start-up break-in procedures I would be most grateful. Thanks.
Jack