rocker assembly questions - 2F
- Thread starter jfnall
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I already had mattressking look into it. He said valves were clanky but didn't mention a knock or anything else.
what was your compression at?? did they use the wrong rings?
I was off by about 4 thousandths maximum on one reading, usually about 3 thousandths off. this was doing it cold though. might try hot measurements and valve setting next!
awesome.
I'll try this later.
I just put on a new to me rocker assembly that doesn't have a crack halfway done support tower 1.... lol.
ill drive it around the block then adjusts hot.
I'm sure ill have to adjust again after everything "wears in" as they say.
Dan
Well, he has hands on - I would follow his advice. Loose valve clearance could clank I guess. Can you look into the cylinder with a mirror on a camera probe so you can see back up to the valves?
I forget what my compression numbers were, but they were an obvious problem, like sub 100 in a couple cylinders.
Set the clearance cold.
Run it to bring it up to temp.
Set the clearances again to spec.
Then check everything again.
Rinse, repeat.
Enjoy.
This. Cold setting won't be far off from a hot setting, and close enough that the 2F will run good enough. Set them cold, drive it for 20-30 minuted to get it hot, then recheck and reset the valves.
Finished wiring, everything resolved there.
Redid valves after a 30 minute drive, did them hot. Almost every rocker arm had loosened, two of them stayed the same, none tightened. two of them loosened as much as .005, and one loosening a whopping .01! I had them all right so wasn’t user error. I had the screws very tight too.
It’s New rocker, maybe things are wearing in, that’s my hope, i didn’t have the valve lash jump this much before, ever with the old assembly, biggest jump was .04 after 200 miles.
Rig felt sluggish today, so not surprised about the readings.
Seems like if I want to know what’s happening it would be pulling the head off to see what’s going on, once again, I could do it but wouldn’t know what I’m looking at if I did so.
I’m open to the idea of pulling the head, and fixing the intake leak as well as I do it, but open to your thoughts on what I should do.
I’ll get HOT compression and valve numbers tomorrow and put em on the thread. And will know a bit more then, but I really just need to determine if I can drive the vehicle or not ASAP. Hence why I just want to pull the head off. I just don’t know how to test the tolerances and examine all the engine comments properly.
Could someone that ain’t a machinist actually help? IE visually inspecting the head and components, can lobes, guides, etc. does it require speciality tools to tell if something is wrong?
Uncharted waters!
Thanks all.
Dan
Redid valves after a 30 minute drive, did them hot. Almost every rocker arm had loosened, two of them stayed the same, none tightened. two of them loosened as much as .005, and one loosening a whopping .01! I had them all right so wasn’t user error. I had the screws very tight too.
It’s New rocker, maybe things are wearing in, that’s my hope, i didn’t have the valve lash jump this much before, ever with the old assembly, biggest jump was .04 after 200 miles.
Rig felt sluggish today, so not surprised about the readings.
Seems like if I want to know what’s happening it would be pulling the head off to see what’s going on, once again, I could do it but wouldn’t know what I’m looking at if I did so.
I’m open to the idea of pulling the head, and fixing the intake leak as well as I do it, but open to your thoughts on what I should do.
I’ll get HOT compression and valve numbers tomorrow and put em on the thread. And will know a bit more then, but I really just need to determine if I can drive the vehicle or not ASAP. Hence why I just want to pull the head off. I just don’t know how to test the tolerances and examine all the engine comments properly.
Could someone that ain’t a machinist actually help? IE visually inspecting the head and components, can lobes, guides, etc. does it require speciality tools to tell if something is wrong?
Uncharted waters!
Thanks all.
Dan
Simplest initial inspection is to remove the side cover and remove the lifter for the valve that was 0.01 over and inspect the lifter surface that rides on the cam lobe. It should still be perfectly flat and polished. If it has failed / failing it will be dished from the cam lobe and no longer polished.
Did the valves again, this time hot. Only 2 valves were off this time, so my prior theory that that the engine was accepting the new rocker seems to be correct, and things were wearing in.
Number 12 and number 9 are still stinkers. 12 was off .004, was loose and 9 was off .003.
Will take compression test in the morning.
Number 12 and number 9 are still stinkers. 12 was off .004, was loose and 9 was off .003.
Will take compression test in the morning.
What is your ignition timing set at?
2 degrees BTDC not including 7 degrees vac advance) . I’m at 3000 feet. When I’m at elevation (5800 feet) I advance it to around 9 (not including 7 degrees vac advance)
I'm going to suggest that that may not be enough advance. FSM says 7*BTDC and that's usually not enough. Try advancing your timing and see if the engine perks up.
Not to belabor a point, but, as I'm sure you know, half of carburetor problems are really electrical (ignition) problems.
Need to know what distributor you run and where you're getting the vacuum for it. Where is important.
Many people find that around 17 degrees BTDC works for their F/2F engines. That's base timing, don't count vacuum advance yet.
My engine can't get out of it's own way when timed to the FSM, I'm just over 3k ft elevation and run at 25* BTDC.
Stock distributor, mattressking examined it, said it looked fine and was working. He helped with vac routing, vacuum is coming off of air cleaner right now.
My massive intake leak is likely what’s causing issues. I think I’ll have better luck getting compression and rings where they need to be by fixing this issue.
Gunna try the cardboard in front of radiator truck today, see if that helps compression via the rings seating better, today.
I took a video of my current setup so you can see. The dizzy I have came with the truck. Like I said it’s not hooked up to the manifold vacuum (see video)
I’ll advance it a bit once my leak is fixed, my biggest goal is to get compression up right now. I just don’t want to cause detonation on my drive home today with the intake leak. I’ve got the JToutfitters header and I can’t get it to seal after 4 tries, may try the copper RTV trick as a last ditch or tinker with the stock manifold (which I have tried before, and it leaked, so will need machining for sure, PITA)
This is my daily hence why I’m trying to do this quickly.
Thank you
Dan
New headers always take work to make them fit right. In the past I've used two of the Fel-pro gaskets, stacked, and the Copper Coat that comes in a jar with the brush in the cap, not the spray on stuff.
What about using the RTV tube styled stuff and outlining the perimeter of the intake and exhaust ports? Bad idea?
Dan
I used 2 man-a-fre header gaskets when I put mine on. I soaked them in water for like 1/2 an hour to soften them some so the high spots could easily dig in. I torque in sequence 3 times starting at 1/3 value. After I fired it and it got good and hot I torqued them again at 100%. Several heat cycles later I did them again.
Prior to putting the assembly on I planed the units on a piece of glass with sandpaper. I made custom stepped washers to apply equal pressure on the skinny aluminium intake and the thick steel header flange. I did longer studs and stainless steel nut. This assembly has been on 2 different engines 3 times total and has never leaked.
Prior to putting the assembly on I planed the units on a piece of glass with sandpaper. I made custom stepped washers to apply equal pressure on the skinny aluminium intake and the thick steel header flange. I did longer studs and stainless steel nut. This assembly has been on 2 different engines 3 times total and has never leaked.