Need advice on valve job

[plow420]

I was having problems with my exhaust valves seating in my head. I did a leak down test with a semi broken tester. Basically all it did was put pressure air into the spark plug holes with the cams out and I was getting leaks from my exhaust valves.


I already had a 3 angle valve job done on the head about 50 or so dyno runs/ 1/4 mile passes and my compression was 150,155,115,155.


I bought oversized valves for my exhaust valves, I purchased the engnbldr stainless valves and his mag/bronze valve guides and had those installed as well.


I had my machine shop fit the guides and new seals and do a new valve job and then when i got the head back i asked if he tested the valves and he said he did and they are all good..


When i filled the ports with water all but one intake valve leaked water. And all but 2 exhaust valves leaked water. I also tapped the on the valves and they still continued to drip.


I already talked to the machinist and he said the valves would will "seat" or "break in" I'm not sure if I really believe this.


The machine shop told me that if I want I can bring it back to him and he will lap the valves. Should I bring it to him, or is this acceptable.


I can attach pictures if it would help.

 

[boost97gst]

Local machinists. Boy oh boy. You're almost better off just sending it to JAM. Wish Bogus was still around, i'd have went to him myself for the head build.

 

[plow420]

He said that he put a 44 degree angle on the head and a 45 degree on the valve, or vice versa. He also told me to just run it and if the valves leaked he will re do it, but that's more work than I should have to do.

 

[boost97gst]

God, I wish i could locate the thread but someone explained why the typical "local" machinists can mess up the valves. It was something about them using maybe a SAE vs Metric tool or brace or something to do with the angle of the cut. I'm talkin out my arse but i think you catch my drift. I'll keep searching for the thread but yea, you are right. I've been run through a total of 3(maybe 4 times) with bad machining. It really hurts the wallet.
Thing is you take a ls1 or ls6(sbc ya know) or a 302 in there and they'll nail it! Why not the 4g63? I've been so frickin stumped by this time and time again.
The guy should give it another shot and make him vac test it in front of you. Thats not an extraordinary request and he should be happy to oblige you. Screw the water, he should have a tester to put vac on those chambers and they should seal. brand new, doesnt matter.

 

[pb_evil]

They need to be lapped to fit properly [DOUBLEPOST=1409525453][/DOUBLEPOST]The 44 is the insert 45 is the valve this is so can be lapped and it is necessary for break in

 

[911gdsmboostin]

some advice. my father owns and operates a very precision machine shop. 98% of work done are extreme high class racing engines and its not uncommon to see 10-60,000 dropped in things like valve jobs are important as anything. I work their as well and do this work. we do some smaller motors. but most of the big stuff is of Corse sbc bbc sbf bbf ans so on and yes a lot of tooling is mostly ase. but when the smaller motors come in it is essential to have it done right because they can be more particular then the bigger stuff... being said that a valve job on a small head can be more important then a sbc head because of valve clearance valve lash and so one. if u put water in the port ( which is not a good way to test) and it leaked theirs something wrong... they shouldn't leak a thong with a new valve job. and mostly all valves ina good machine shop are lapped in and vac tested... meaning it would be impossible for water to leak because e the air isn't soposto leak break in will help the valves seat better but if their leaking water you are wayyyyyyy off.. they thing would run like crap in my opinion not saying it wont run but you will loose a lot. our machine shop is one of the best in the area not trying to brag but we come with a very high reputation because how well the quality is. nothing leaves unless its right and if its wrong we make it right we donr beat around the bush and say it need break in we would rather take apart now and fix it before u start it and make sure before u start it and possibly damage it. a valve job is as this if the valve is at a 45 degree angle the seat should be as well no 1 degree off they are soposto be the same at some angle a 3 angle valve job is as fallows this is an example to get the point to you. their is 3 angles made a top a middle and a bottom the top is to round the seat for air flow so its not a straight edge will say it 30 degrees . the middle is where the valve seats and should be the exact same as the valve no 1 degree off will call it 45 degrees the bottom is to round the bottom half for air flow will call it 50 degrees. the 2 top angles round the seat and the middle angle is the seat and when lapped in u can see the angle and the lapping helps seating the valve and makes it seat better and seal better. the valve it self can be rounded they call it a back cutting a valve ( putting an angle on the back side of the valve for air flow) it doesn't give u 50 hps but it assist in the air flow, flow more air make more power.. if your leaking water you got problems they shouldn't leak air let alone water think about it... when the valve seats it hasto hold over 100 psi of air to combust if its leaking water that means its leaking a lot more air.... I would have these vac tested and try it at another machine shop if possible to get a second opinion. some places don't take as much care in the smaller engines' because they are big v8 guys like my dad but he is more committed to a good job and a good rep then let his opinion take over. u can actually change the angle of the valve when grinding valves by just applying too much pressure to it because their so small they bend easy you have to use a very light touch as where v8 valves wont bend hardly at all could be an honest mistake or could be they didn't pay attention either way I would highly recommend getting it check again before you put t back or try to ignore it coz I promise it will make problems somewhere. if you ever need advise or have questions don't be afraid to ask. im not as knowledgeable as I would like but just working in the machine shop for the past few years with 2 guys with 30 plus yrs experience you learn a lot. now he has machines dedicated for valve jobs alone can do 6 and 8 angle valve jobs for big time engines' but that's besides the point.. my advise get them checked and redone if needed.. vac check should pull at least 10-15psi at least that's not being lapped in. being lapped in should do 15-18 at least if not more and make sure when being checked that all possible air ways are sealed keep in mind your checking 2 valves at once when doing it they both have to be right if ones wrong they other will get false readings. good luck and let me know if you need any other advise, best of luck as well