Hi,
So im waiting on my newly rebuild benson sleeved, manley rods, cp pistons etc.... in other words a rebuild that cost me about 3500 dollars. I have a built GSR JG head that i will assemble onto this block The head is used.
Im kind of stressed from damaging my newly built block by using a head. Instances is drops a valve, or something, which would suck!

So pretty much i want to take my head to a machine shop and do series of tests to make sure the head is good, it wont drop a vlave and damage my new bottom end etc...

Cliff notes; Guarantee that my head wont malfunction and damage by newly built bottom end?

Im freaking paranoid....

 

qucik bump for my gay paranoid self.....

im paranoid about everything......

someone on this board told me i should be paranoid im gonna die soon lol

 

Ha, how funny. Just last month I installed a used JG head (from ebay) onto my new billion dollar bottom end. Looks like we're in the same boat.

But... I completely ripped the head apart. I spent a month cleaning and inspecting all the components. Getting the carbon off of the valves and exhaust ports took forever. I also had to lap the valves back in.

But as far as tests, all I can think of is this:

1. Test the spring pressure on all valve springs
2. Remove the cam and inspect the lobes/cam journals for wear. The cam that came with my JG head was ruined and I had to throw it away. It just had too much wear. I hand polished out the journals, threw in another cam, and it came out perfect.
3. Check the valve seals
4. Check to make sure the valves are sealing - fill the ports to the brim with water and use your palm to compress the water into the ports - if any water gets past the valves (into the combustion chamber) you'll need to lap the valves in


It'd be best if you just fully disassembled the head and cleaned everything. It sounds like you're just as parranoid as me . I spent a full day alone just cleaning all the oil passages with a gun cleaning kit. If you have the head disassembled, you can test all the springs, test all the seals (slide the valve up and down with your finger over the seal and feel for suction), and lap the valves back in for a perfect seal.

If you have money to burn, I'd just get a fresh valve job instead of lapping them in. It took me a week to lap in all the valves and get a perfect seal .

 

so a fresh 3 angle valve job is a guarantee that its good?

thnks for info

 

Sorry but theres no way anybody can guarantee that the head is ok from online.Take it to a local shop that's trusted and have them look it over,only way to be sure.


Yeah 1,000 posts

 

congrats , as for JDMSI your prob the most paranoid person on HT . As EnzoSpeed stated, have a look at the head, see if anything is out of place etc.

 

yea im obviously going ot take it to a machine shop. What kind of tests can they do to prevent valve drop etc...

ill get the springs tested, what else?

thanks

 

<TABLE WIDTH="90%" CELLSPACING=0 CELLPADDING=0 ALIGN=CENTER><TR><TD>Quote, originally posted by JDM00SI &raquo;</TD></TR><TR><TD CLASS="quote">yea im obviously going ot take it to a machine shop. What kind of tests can they do to prevent valve drop etc...

ill get the springs tested, what else?

thanks</TD></TR></TABLE>

That's pretty much it. You should also inspect the retainers for warpage or damage (JG retainers are kind of soft).

Check the exhaust ports - if they are grossly caked over with carbon, then your valve seats are probably gunked up too. That's why I had to lap my valves back in.

But in any case, a fresh valve job is always best. If you have the money, you can do what I really wanted to do - send the head to Portflow. They'll tear it down, clean it, do a valve job, re-assemble it and ship it back to you for $250.

 

I have only seen a valve drop when a Ti retainer is used with a stock keeper. The valve will pull through the retainer.. something like this used with a stock or poor aftermarket material valve will cause a catastrophic failure.

 

I've never even heard of aftermarket keepers

 

<TABLE WIDTH="90%" CELLSPACING=0 CELLPADDING=0 ALIGN=CENTER><TR><TD>Quote, originally posted by EnzoSpeed &raquo;</TD></TR><TR><TD CLASS="quote">I've never even heard of aftermarket keepers </TD></TR></TABLE>

same here....

i think i might just send it to Portflow and have them tear it apart, clean everything etc.....

bump

 

Ferrea and Manley are the only companies that make a aftermarket keeper...go with the best you recieve the best.

 

cool.

 

Hot tank, crack check, competition 3 angle valve job, surface, new seals is the package that im going to get....

Does the 3 angle valve job include test spring rates?

What is the test called to test spring rates?

 

I've also seen valves drop from cheap e-bay tit retainers hitting the bottom back of the rocker which dislodged the valve locks

 

<TABLE WIDTH="90%" CELLSPACING=0 CELLPADDING=0 ALIGN=CENTER><TR><TD>Quote, originally posted by budsmachine &raquo;</TD></TR><TR><TD CLASS="quote">I've also seen valves drop from cheap e-bay tit retainers hitting the bottom back of the rocker which dislodged the valve locks</TD></TR></TABLE>

ouch....

So the machine shop will examine all this and ensure me that it will not happen right?

Thanks

 

<TABLE WIDTH="90%" CELLSPACING=0 CELLPADDING=0 ALIGN=CENTER><TR><TD>Quote, originally posted by JDM00SI &raquo;</TD></TR><TR><TD CLASS="quote">

ouch....

So the machine shop will examine all this and ensure me that it will not happen right?

Thanks</TD></TR></TABLE>

 

<TABLE WIDTH="90%" CELLSPACING=0 CELLPADDING=0 ALIGN=CENTER><TR><TD>Quote, originally posted by JDM00SI &raquo;</TD></TR><TR><TD CLASS="quote">

ouch....

So the machine shop will examine all this and ensure me that it will not happen right?

Thanks</TD></TR></TABLE>

JG heads come with JG retainers, so don't worry about that useless bit of info.

As for the spring testing - all the machinists do is compress the spring with a caliper - a dial gauge mounted on the caliper displays the seat pressure.

Different applications require different seat pressures.

Is the head a "pro series" head? I.E., does it have a full JG valve-train?

 

yes pro series gen 2

 

The pro heads come with a full JG valve-train, so everything is meant to work together. That's the best scenario possible.

The odds of dropping a valve a minute. If you really feel like testing the seat pressure, just make sure that the springs test out within JG's specs. You can probably call them and ask what the spring pressure should be.

 

see it is a full jg valve train. but after i bought it the exhaust valves look stock.
thats why i want ot get it tested becaus im not sure what else is in that head.

 

If a magnet sticks to the exhaust valves, they're stock. If a magnet doesn't stick, they're stainless


I thought the same thing as you - my exhaust valves looked stock (check my sig for pics). But then after cleaning them and trying the magnet trick, I realized they were JG valves (stainless metal is not magnetic).

 

cool what did you use to clean them? Thanks

 

<TABLE WIDTH="90%" CELLSPACING=0 CELLPADDING=0 ALIGN=CENTER><TR><TD>Quote, originally posted by JDM00SI &raquo;</TD></TR><TR><TD CLASS="quote">cool what did you use to clean them? Thanks</TD></TR></TABLE>

About 10 hours of my life

Aside from that, I bought some goodies from Pep Boys: a 2" paint stripping wheel, a bunch of 2" polishing wheels (like brillo pads), and a drill bit adapter that let me attach the wheels to my electric drill. I secured the drill in a vice and locked it in the on position - that way, I could use both hands to swirl the valves against the spinning discs.

To clean them, it hit each valve with the stripping wheel for about 5 seconds. The stripping wheel WILL sand off the metal rather quickly, so I only used it to take off the highest formations of carbon.

After that, I spent about half an hour per valve with the polishing wheel to finish the job.

All the Pep Boys stuff I listed was rather cheap and flimsy - which was fine because it only cost me $15 for everything. And don't bother with chemicals - I spent weeks soaking the valves in all sorts of different solvents - nothing works.

 

hmm.... how do u knwo if your cam has excessive wear?