Engine rattle on down rev

[losh1971]

All rods are the same Lex.

 

[losh1971]

Using the TW in total the bolts are going down about half a turn.

 

[losh1971]

Third valve back half turn, fourth valve 1/3 turns.

 

[losh1971]

I am making rods so that i can only just move them with my fingers, before tensioning up to spec.

 

[losh1971]

Wondering now if I should even bother, since it seems they may not be getting enough preload.

 

[losh1971]

Cyl 1 pass side almost 3/4, second one in 1/2 - 3/4 third cyl from the front same side about 1/2 or a smidge less.
Putting rocker cover back the pass side as there is nothing I can do myself to increase preload. Leaving driver side off upon advice as to what to do with front most rod and hole.
Edit: there could be around an eighth of a turn more as that first bit of preload is hard to gauge, because it is hard to feel with the Tq W.

I have to stop now as it's beginning to get dark and if I stop now the cursing won't begin. I have the very front lifter left to go on the drivers side, once I work out what to do. I also ended up using Loctite blue on the bolts after removing and cleaning them with a rag and brake cleaner. The threaded holes in the heads may or may not be oily, can't tell.

 

[delcowizzid]

1/3rd isn't a lot of preload .the pushrod you think is close to hitting did you check it at all lifts it will move a bit as the rocker pivots.

 

[losh1971]

1/3rd isn't a lot of preload .the pushrod you think is close to hitting did you check it at all lifts it will move a bit as the rocker pivots.

I run the engine without the drivers side cover on and that side was working all good. It does have clearance but at most it would be 1mm from the bottom of the hole. 1/3 on a couple but I'd dare to say that those couple are quite likely more like 1/2. Like I said it's hard to gauge it exactly with the Tq W. I did a couple of cyls with the ratchet and finished it with the Tq W and they were certainly at least 1/2. I spun the rods in my fingers and move the crank and tightened the rocker until I could barely turn it in my fingers. Because the Tq W is long and you don't have heaps of room it becomes hard to be precise.

 

[losh1971]

The issue i have now is whether i file out the hole or leave it? I don't have any way of increasing the preload without a mill. I am thinking the chain is probably fucked given the engine probably has 200k on it. Don't know if that will help preload but I have to do something. Its booked in for next week to have the timing cover removed and checked the chain, plus an oil pressure test first up. Unfortunately its looking beyond my capabilities.
Kinda wishing i didn't spend the big money and maybe should have settled for less power. Because I am not sure that the problem will be resolved without extensive work and replacement of lots of parts. If the issue is preload and i need to have milling done that could easily add another $400 to the job. The engineer is very pricey.
In hindsight i should have kept the old rocker gear in order so that i could have sold the Mace set and refitted the old ones.
Unfortunately the one bloke in Launceston who could name it with just a listen, doesn't want to even listen, because he is the best but he is a grumpy old bastard.

 

[delcowizzid]

Set of pushrods is cheap