valve adjustment on 350

[prockvoan]

Did a seach in the forums,didn't come up with anything.So,can anybody tell me the right way to adjust vales on a 350?Looking to adjust them without running the engines.I know how with the engines running,but the boat is dry dock.Oh,need to know on a ccw and cw motor too!Both engines have less then 100 hours on them,I just had a bunch of problems with both from fuel to water in the fuel.Now that those problems are out of the way(I hope)time to adjust everything,thanks.

 

[rodbolt]

Re: valve adjustment on 350

unless they have been disturbed there is no reason to nadjust the valves on a modern engine with hydraulic lifters.<br />but there is a post about a 339 motor I just replied to that describes valve train adjustment on the v6 and v8 chevrolets with adjutable rockers. you really need a service manual before opening up the engine. not all chevies have adjustable rockers. the only difference between the right and left hand motors is the rotation while adjusting. the procedure is the same.

 

[prockvoan]

Re: valve adjustment on 350

Last time I had ran these engines,I hear valves making nosies.Found my book that discribes how to do it,not a backwards motor.<br />I did the normal rotation motor,found the rods were able to turn.So I had went back readjusted them per the book.To hot outside down in the hole now to try the other.I will give it a try thursday.

 

[Fishermark]

Re: valve adjustment on 350

When you say you "found the rods were able to turn," do you mean the push rods? I always adjust my valves / rockers without the engine running. Having said that, it does take a little "finese" to determine when the slack is taken out and a load begins. The push rods with still "turn" even after coming into contact with the rocker arms. Just something for you to be aware of.

 

[Bt Doctur]

Re: valve adjustment on 350

Most use hyd. lifters, to set while running, bring to temp, loosen until clicking is heard, adjust down until no noise, then go 3/4 of a turn more.<br />cold, rotate motor untill both valves are closed, adjust until you cannot spin the pushrod with your fingers and go 3/4 of a turm more.

 

[Limited-Time]

Re: valve adjustment on 350

check out this link http://www.iboats.com/cgi-bin/ubb/ultimatebb.cgi?ubb=get_topic;f=24;t=011164#000003's.

 

[prockvoan]

Re: valve adjustment on 350

Thanks guys,I had adjusted them per the book.Most of the push rods I was able to turn once I rotated the engine to #1 tdc.<br />Thanks Limited-Time,that link pointed out how to adjust an opposite rotation engine that Don S posted.My book didn't have that.

 

[Buttanic]

Re: valve adjustment on 350

When the engine is not running the lifters bleed down because there is no oil pressure to keep them pumped up so the pushrods become loose and they can be spun

 

[prockvoan]

Re: valve adjustment on 350

I was thinking on that line too!So,when I get the boat back in the water,I will check them again.

 

[prockvoan]

Re: valve adjustment on 350

Fired up the port engine yesterday.Yep,valves were to tight.Readjusted them,sound fine.Problem is now when gunning the throttle,I'm getting some back fire.Timing is set at 8 drg BTDC at 700 rpm's and at 3000 rpm's it is 27 drg at TDC.<br />Engine has a 4 barrel rockchester quad and when tryind to adjust the fuel/air,closing them all the way in,the engine has no change and running.Has auto choke,which is opening.That carb is a new rebuilt.Timing is steady.

 

[Don S]

Re: valve adjustment on 350

You either have a vacuum leak or a defective carb.

 

[prockvoan]

Re: valve adjustment on 350

I had checked for a vacuum leak by spraying some WD40 when the engine was running,no change there.I do have another carb for the other engine,I will change it out and give it a try.

 

[lowshovel1]

Re: valve adjustment on 350

then there is a posabilaty that your valve adjustment was'nt done corectly and you bent a pushrod or 2 ?

 

[prockvoan]

Re: valve adjustment on 350

Originally posted by lowshovel1:<br /> then there is a posabilaty that your valve adjustment was'nt done corectly and you bent a pushrod or 2 ?

I don't think I had bent a push rod.The engine runs fine as long as I don't gun the throttle.If I bring it up slow,its fine.

 

[Wellcraft 89]

Re: valve adjustment on 350

Tell us about your fuel to water problems<br />You may still have some water.<br />If you have chkd timing,valve adjustment,bent pushrods,or a valve that is sticking or a valve spring problem.<br />Or even a lifter problem.<br />Or even a cam lobe wear problem.<br />When you say backfire is it throught the carb or out the exhaust?<br /><br />Rich

 

[prockvoan]

Re: valve adjustment on 350

Back thru the carb.Don't have water problems anymore.This engine has about 20 hours on it,new,not rebuild.But still,I had ran the engine pulling gas direct from a 5gal gas can.When I get off later,I will swap carbs from the other engine which is a new rebuilt one too and give it a try.I was died after a all day working on it from 6am to 730 last night with no break.

 

[prockvoan]

Re: valve adjustment on 350

Guys,boy did I dumb out!Got home yesterday after work,went to change out carbs.The more I got to thinking about what went on when adjusting the valves,the more I whated to kick my own @ss.<br />Now for the dumb out.When I had fired up the engine,I had put a timing light on it.Working inbetween two engine in the hole is a bit-h in itself.Looking over the engine from the starboard side,setting the timing,Like a dumb @ss,I had put the timing at 8drg ATDC,yes after!Bad thing was,it was ok before.Well,things when down from there.That is when I had set the valves at.When I had finish,I had check the timing again,and at that point,I set it back to 8 drg BTDC.Looking back,thinking after a 12 pack of buds,WHAT A @SS!<br />What really brought it back was when I had set up a vacuum gauge and changing out the carb last night.After starting the engine and warmed up,the vacuum reading at 700rpm's was reading from 9.5" up to 15",back in forth.Rasing the rpm's up to around 2500,vacuum reading was at 17" flat.<br />Looking at a web page that has vacuum reading and what they mean pointed out that the valves were adjusted out of time.Like a ton of bricks fell on me,the second time I what to kick my own @ss!<br />Come tuesday,I will have to go back and readjust the valves.What a pain in the @ss because of the hoses and the exhaust manifolds need to be backed off to pull the valve covers.Nothing like doing something twice!I will let ya'll know how things work out on this.Before I fire up the engine,I will most likly check to see if I had bent any push rods by pulling them one at a time.<br />Thanks again for ya'lls help!<br />Oh,I will leave out the buds till after working on the engine

 

[Buttanic]

Re: valve adjustment on 350

Roll the push rods on a piece of plate glass to check for straightness. Plate gless is about the flatess thing there is other than a precision ground granite surface plate.

 

[prockvoan]

Re: valve adjustment on 350

That is what I was planning on doing.They will click as you roll them if bent.

 

[prockvoan]

Re: valve adjustment on 350

OK guys,did the valve adjustment over again.Check all push rods,they were fine.Pull one at a time and put them back in the same place.<br />After asjusting them with a vacuum gauge hooked up,the vacuum came up to 20.5" at idle(700 rpm's).Reving it up fast,the vacuum would drop down to around 5",then shoot up to around24" to 25" then drop down to 21".<br />Now I still have a problem with back firing out of the carb.I had swap carbs with the same problem.Dam rockchesters!I had tryed to adjust them with no change.I was able to close off the 2 screws on the front of the carb,no change on rpm's.Open them up to around 1 1/2 turns were they were.The choke plate is opening after the engine is warm.The only vacuum line on the carb is for a line to pull off the fuel pump.Vacuum is telling me everything is fine as for as any leaks.<br />I had pulled the spark plugs,had some carbon build up,they are new.Using NGK BR6FS,set at .35.I had clean them up and will reinstall them today,but I will not fire up the engine till I can get some info on how to adjust one of them dam rockchester carbs.<br />Any help?Thanks guys!