1600 dp valve guide specs

[fifty-five]

I've got my heads at the machine shop and the guy there called and told me my valve guides measuered .004 on all but one exhaust and it measured .005. I am wondering what they are supposed to be . He is a awsome machinist but not used to VW stuff so he didnt know what was right. I'm just wondering how far out these are or are they within spec?

Thanks,
Mike
_________________
FUCK CANCER
1955 Ragtop Oval
"Lil Wheezy"
2276 turbo

[vwhp2008]

Hey Mark

.004 is within spec.the reason you probably have a .005 is because that one exhaust guide was worn down and needed to be replaced with an oversize.

[keifernet]

[fifty-five]

pretty sure it was the ID. The guy at the machine shop just called me while he had the heads apart and gave me those measurements. I was just wondering how far off that was. I got the engine back together for now. This is just a get me by until I can save for a bigger engine 1600 dp and not a daily ride. maybe once or twice a week in good weather (not to hot and only a very slight chance of rain).

Thanks,
Mike
_________________
FUCK CANCER
1955 Ragtop Oval
"Lil Wheezy"
2276 turbo

[modok]

The guide OD in old factory heads seems to be .475"
Most "standard' replacement guides are more towards .476"

The way to do it right, is measure the bore in the head, and choose a guide so you have .0015-.002 press
It is pretty common to need an oversize guide in heads that have a lot of miles.

edit: huh, the question I was answering dissapeared........
Oh well i'll answer the OP
clearance specs
intake .0015-.003 wear limit .005
exhaust .0025-.004 wear limit .006

I just made that up, but it's probably right
the guide is supposed to be 8mm and the clearance is built into the stem OD

[Adriel Rowley]

[modok]

hammering them in works just fine. (lube with anti-sieze, can use a 8mm bolt as the driver)
The tough part is removing the old ones, and the other tough part is reaming the new ones to size.

Seems to me the best way is to drive them out towards the chamber.
You can buy a drill to core them most of the way through, or tap a bolt into the chamber side and push on that with a 5/16 rod.
Drill off the part that sticks out towards the spring, some are stepped or locked in here.

Some heads you can just push the guides right out, but not these. If you try to just push them out with a driver; 50% chance you just mushroom the end like a rivet, and might even crack the head.

[Adriel Rowley]

[RockCrusher]

[modok]

It isn't easy. rebuilding vw heads is pretty hard compared to the average engine.

I got two ideas:
buy a brand new k-line brand 8mm(.315) reamer and hope it is sharp enough to do the job. Bronze is hard to ream because it is tough and gummy. Drive it with a 500 rpm drill, or maybe ream one a day cause you'll be tired if you try to use the amish method.

OR, call your local auto machine shops and see who has an adjustable diamond reamer or diamond hone. The diamond hone cuts SO much better than a regular reamer it is worth it. (but they cost 500 each, so you don't want to buy one)

If the bore in the head is generally round and straight, just use an oversize guide of the appropreate size.
If it is bannana shaped, you'll have to fix that somehow.
Once again, you need the right size reamer or ridged hone of some kind to make it round again.

[RockCrusher]

If you've never done head rebuilding before than this is not the place to start. If you just want to learn then use a junk head to start with.

RC
_________________
paul@rcaircooledvw.com Please use email for all general inquiries.

I will be happy to speak to anyone who has a serious inquiry (meaning real potential business for RC enterprises) or a parts order. Due to machining noise causing missed calls all calls will be returned promptly.

[modok]

Probably just saving money on the valve job.
It would be great if people brought in the head with new guides in it, I'd discount 40$ for that.
Would probably be best to let the shop ream them, as what size pilots they have is another consideration.

[Adriel Rowley]

[RockCrusher]

Drilling the guides is to leave just a thin wall that will actually stretch and shrink the guide so it easily drives out. don't just pound them out as that will tear up the aluminum they seat on in the bores. Putting the new guides in.....heat the head to 400 in the oven and quickly drive a couple guides in then heat the head back up to do the next 2 guides. Heat both heads together so you can throw 1 back in the oven while taking the other out. (Hint: don't use the microwave.....Hey! You never know ).
_________________
paul@rcaircooledvw.com Please use email for all general inquiries.

I will be happy to speak to anyone who has a serious inquiry (meaning real potential business for RC enterprises) or a parts order. Due to machining noise causing missed calls all calls will be returned promptly.

[Adriel Rowley]

[RockCrusher]

Cooling the guides is fine but the effect is really nothing since they are dense and small in diameter so they will shrink far less than .0001 while the aluminum heads will grow pretty significantly.
_________________
paul@rcaircooledvw.com Please use email for all general inquiries.

I will be happy to speak to anyone who has a serious inquiry (meaning real potential business for RC enterprises) or a parts order. Due to machining noise causing missed calls all calls will be returned promptly.

[modok]

Sorry about the Amish joke, poor taste on my part.
I was trying to convey that running a reamer through bronze takes a lot of force, you will see.

The guide ID needs to be adjusted based on the size of the stem.
See the clearance specs above.
The last three sets I did I diamond reamed the guides to .3145", as the stems of my PEP valves were all right around .3120".
We have a .3142 pilot for the serti so it all worked perfect.

The guide ID can be checked by:
-expandable ball gauge
-mini snap gauge
-special valve guide bore gauge
-using a pilot as a go/no go gauge

The guide bore size in the head can also be checked with a ball or snap gauge OR by using other guides as go/no go gauges

as for the guides; a .002 oversize brand X guide is .002 thou bigger than a brand X STD size guide.

After installing new guides the seats need to be recut or reground so the seat is concentric with the new guide and the proper width and location on the valve. I believe in Sioux grinding equiptment, VGS-20, or Serti.
Those stupid DIY file cutters are kids stuff, I would not use them on my lawn mower. (ok, actually I did once but now I know better)

I would be happy to list what tools will be needed to do an industry standard valve job, and give general advice on how to use them and check your work.
Unfortunately, if you do not currently have ANY of these tools it will take quite a while and quite a lot of money to collect them all.

[RockCrusher]

By "file type" are you referring to the hand driven carbide cutters Goodson is selling?
_________________
paul@rcaircooledvw.com Please use email for all general inquiries.

I will be happy to speak to anyone who has a serious inquiry (meaning real potential business for RC enterprises) or a parts order. Due to machining noise causing missed calls all calls will be returned promptly.

[modok]

There have been many brands of them, some are better than others I'm sure. I'm thinking they were made by neway? i forget
The advantage of grinding the seats, is it takes very little force on the pilot, and naturally cuts round and on center with no other support.

Cutting valve seats often results in wavy or ovaly seats or seats with a lot of runout, the solution for that has been very stout machines like the VGS-20 or Serti. The machine FORCES the cutter to track round.

[modok]

I just looked at Neway's web page, it says:
"no need to lap like old fashoned grinding equiptment"

hahahaha THE IRONY
You can grind any seat from iron to stellite to stainless to high nickel, no lapping needed if done right. WIth a full set of sioux pilots and stones I can grind any seat perfect.

There are alot of jobs the neway cutters are not able to handle, and on used vw heads those exhaust seats can get REALLY HARD and crispy, the files don't like chewin on that