Lap the valves or not?
#1
Lap the valves or not?
Im currently doing a stock bottom end rebuild and throwin a cam in it while im there. I have the heads off, and I was wondeirng if it would be worth the money to get the heads rebuilt with a competition valve job, or just lap the vlaves and install my new springs? I am on a college budget, and the heads look to be in pretty good shape.
#2
Well, if you are rebuilding the bottom, then you should also bring the heads up to snuff. If you are replacing springs, I assume you will be getting ones to match the proposed cam specs. So I believe that you should certainly have your valve seats checked to make sure they aren't boogered, but....I believe you would be well served if you had a machinist do a valves pocket job done. The valve pockets are the greatest restriction to head flow and having the heads pocketed should really benefit your performance. You don't have to get new, or bigger valves or spend much denaro on doing a complete porting job on the heads, but if you plan on having a machinist lap your valve seats (even if they don't need it) you are going to pay for it.
So get a pocket job, but....make sure that a head specialist does the work. It may cost you more money than just lapping, but much less than a complete head job and the benefits along with a cam will really wake that puppy up. Also, you can have the springs installed to the correct height and wind up with a plug and play top end.
Bottom line: If you do your home work on this rebuild, you will probably end up spending the same or less money than you would than if you just rushed into the job. And be sure to have your ducks lined up before you start which will require you to use this site and the expertise and experience the members of this site. JMHO
So get a pocket job, but....make sure that a head specialist does the work. It may cost you more money than just lapping, but much less than a complete head job and the benefits along with a cam will really wake that puppy up. Also, you can have the springs installed to the correct height and wind up with a plug and play top end.
Bottom line: If you do your home work on this rebuild, you will probably end up spending the same or less money than you would than if you just rushed into the job. And be sure to have your ducks lined up before you start which will require you to use this site and the expertise and experience the members of this site. JMHO
#3
I have been planning this rebuild for about 6 months now, doing research every day, im going crazy b/c I want it done. I was planning on lapping the valves myself. The rebuild I got quoted is $300, he dissasembles the heads, cleans em, resurfaces the heads, does a competition valve job and re-installs everything. This is with me providing the springs. I know this guy does GREAT work. Only reason I am asking is I had a friend who did the same cam on his motor, all he did was lap the vlaves himself, and the car performed great. I want to spend the money, but I am not sure if I can come up with the extra 300 bucks for this thing.
#4
Perhaps you can have someone do a pocket job for the 300 bucks and you can finish it up by installing the springs. And you never know, the guy might do it for you for the same $ since he would need to see how well the valves fit which can include installing the valves and springs.
Bottom line. You get charged by the hour so if you have them resurface (which it may not need---and I don't know what you mean by a "competition valve job" It should'nt take more than 3-4 hours @ 75 hrs----voila---worth every penny. So find out what a competition valve job includes because you will get more benefit from a pocket job than you will from cleaning, resurfacing and valve grinding and.....know what you are talking about when you say that someone or some shop does "great work". There are machinists who can clean and resurface and grind valves and there are those who know what the hell they are doing when it comes to doing a pocket job to increase the performance of the heads. I.e, just doing a routine job which does not include pocketing the valves merely brings the heads up to snuff, whereas a increasing your flow will add power and make good use of the cam.
All of us have had mechanics and machinists that we swore were top notch only to find out too late that there was no basis for that conclusiion.
Just sayin'.
Bottom line. You get charged by the hour so if you have them resurface (which it may not need---and I don't know what you mean by a "competition valve job" It should'nt take more than 3-4 hours @ 75 hrs----voila---worth every penny. So find out what a competition valve job includes because you will get more benefit from a pocket job than you will from cleaning, resurfacing and valve grinding and.....know what you are talking about when you say that someone or some shop does "great work". There are machinists who can clean and resurface and grind valves and there are those who know what the hell they are doing when it comes to doing a pocket job to increase the performance of the heads. I.e, just doing a routine job which does not include pocketing the valves merely brings the heads up to snuff, whereas a increasing your flow will add power and make good use of the cam.
All of us have had mechanics and machinists that we swore were top notch only to find out too late that there was no basis for that conclusiion.
Just sayin'.
#5
They are aluminum heads, they will at least need a surface. You can have them vac checked which will tell you the condition of the valve seal, and if at that point you find out that the heads need work, find out what their "competition" valve job includes...
#8
The valve job's in those heads tend to hold up pretty well. You can lap them yourself first and if you see any spots that don't come in THEN take them to the shop for a comp vj. Use a sharpie to mark the seats and valves so you can clearly see where the lapping compound is working. If they do lap in then I would absolutely take it to a shop to have them set up spring pressure and if you have the bux, get some pocket borting/bowl blend done.
#9
The valve "pocket" is the area in the port right above the intake valve. This is the area where porting typically has, by far, the most bang for the buck. Maybe 75% of the flow increase of a complete porting job for a lot less $$$.
Rich
Rich
#12
Thats not bad. I am trying to spend as little as possible on the heads b/c I plan on going with a set of LE heads 8 months to a year down the road. So if I can get out with a simple stock style valve job and resurfacing I am going to try to. I just need to find some shops who will do that around here, because the shop I have been tlaking to said $300 a set for the rebuild, and thats all he offers.
#14
How much do stock valvejobs usually run? I really just wanna get a stock valvejob, get the heads cleaned and resurfaced. I dont really need a competition valve job on this thing. I would like to try and get out for $100 to $150 bucks if possible. What do stock valve jobs usually run?
#15
Do as was mentioned as far as lapping your own valves. Have the shop take off the minimum as far as milling them to make them flat. Have them do the pocket porting and set up the springs installed height. If it cost you a little more money than you are looking to spend, tough luck, just do it!!!!