Starting my top end rebuild, But now I am concerned because of this Options

[LukeD]

This thread has made me nervous
http://www.914world.com/bbs2/index.php?act=...=ST&f=2&t=33950

I have my engine ready to pull in the morning to do top end rebuild and after reading this thread about lapping the cyl to the heads I am getting worried.

I am having my heads re-built and buying new P&C's. What is the proper method when bolting the heads back on? Use seals or lap them. I have no idea how to lap somthing properly except my wife (IMG:http://www.914world.com/bbs2/html/emoticons/grouphug.gif) so what do I do? I watched Jake's type IV teardown and assembly and he made mention of not using the seals because of the buliten but didn't say anything about lapping either.

I am tempted to take my pulled engine down to my local VW shop and having them do all the work because I am scared LOL

Luke D

[Mueller]

QUOTE (LukeD @ Jun 27 2005, 05:06 PM)

I am tempted to take my pulled engine down to my local VW shop and having them do all the work because I am scared LOL

what method does the shop endorse???

Both methods obviously work otherwise Jake, nor Mark or the Cap'n would still be in business.

Is someone helping you build the motor? Are you getting advice for it from the shop?? If so, use thier recommended procedure so if something does go wrong, you won't hear "I told you so" (IMG:http://www.914world.com/bbs2/html/emoticons/smile.gif)

[tat2dphreak]

QUOTE (Mueller @ Jun 27 2005, 07:17 PM)

QUOTE (LukeD @ Jun 27 2005, 05:06 PM) I am tempted to take my pulled engine down to my local VW shop and having them do all the work because I am scared LOL what method does the shop endorse??? Both methods obviously work otherwise Jake, nor Mark or the Cap'n would still be in business. Is someone helping you build the motor? Are you getting advice for it from the shop?? If so, use thier recommended procedure so if something does go wrong, you won't hear "I told you so" (IMG:http://www.914world.com/bbs2/html/emoticons/smile.gif)

yep, the thread even says... either will work... if you want more of the same 3 opinions shoptalk forums will have a TON of them. relax..

[LukeD]

I am doing the work myself aside from sending my heads off.

Anything to watch out for when replacing the P&C's and using the same rods?

If I drop the engine off I am looking at about $800 in labor not including parts.

I would rather use that money for other things but if it has a better chance of being done right then it is money well spent. But after watching Jake's video I know I can do it but doing it perfectly right is another story.

LukeD

[echocanyons]

Luke,
Dont sweat it.
Use the seals or dont but dont lap your heads (IMG:http://www.914world.com/bbs2/html/emoticons/dry.gif) .
When are you dropping that puppy I'll give you a hand.

[Allan]

When I rebuilt my motor I tossed the head gaskets and lightly lapped the head and cylinder with some valve grinding compound. Seems nice and leak free so far...

[LukeD]

Well, decisions have been made,

Heads are going to Rimco
Buying 96mm P&C's probably J and E's
Not using head seals


After Kelly "echocanyons" calming me down on the phone from uncontrolable hyperventalation (IMG:http://www.914world.com/bbs2/html/emoticons/icon8.gif) I am confident, with his help, we can do the job properly.

Thanks buddy, after we're done we are going out for drinks on me so I can (IMG:http://www.914world.com/bbs2/html/emoticons/drunk.gif)

Luke D

Pics to follow on my Top End rebuild thread

[scotty914]

kelly lapping the heads to the cylinders is the best thing you can do even if you do use the seals. what the lapping does is it ensures the tightest possible fit. when i did the rings on my old 1.8 i lapped them in, and as you lap you can see the high and low spots, i was only getting about 80 % seal before i lapped, and 100 % after.

as for the original question jake and a few others including VW say no seals, but i did use the seals on mi 1.8 and they were fine for the 30 k mile i kept the engine for.

[echocanyons]

Scott,
Not much experience with the type fours only type ones(&356 T1's) but...

Why does the factory head not fit without machining? Warping?

If lapping the heads should be done with every build why would you use a seal between, if you use one does the seal seat and make up the difference?

How much should the heads be lapped and how do you know when your piston will have enough clearance...what are the tolerances?

If a thorough inspection show the heads to be straight why would you need to lap them? How thorough inspection is needed and what is entailed?

If they are torqued down properly they should seat, shouldn't they?

Instead of lapping why not use a copper seal or spray/brush on copper coating to make up the difference and hold the seal without cutting your heads down?

Is a lap job part of every head job? ( I know it sounds bad)

[scotty914]

there is also another thread going on this too, if everything is brand new and has been machined perfect the the lapping would be un nessessary. but if the cylinders are not trued they can be off by a little ( dont know what a little really is ) basicly lapping them in is just perfectly mating the 2 surfaces. if the surfaces where a perfect match then they would not need it. as for the cutting of the head, if it removes .0001 material to true it up then its not a big deal. but if it takes .001 then that head cylinder combo has more problems.

as for the head gaskets that is a toss up, i used them because at the time thats what was done.

also the gaskets would not really fill any imperfections, and you would not want any sealant between the heads/cylinders/seals due to the fact as soon as it burns off you just lost head torque and maybe even the seal that it made

[echocanyons]

Are you talking about lapping the cylinder or the head?

I just think there has got to be a better way than removing material from the heads.

For this particular application he is having his heads professionally refurbished and Luke is using new P&C's. Would the truing of the face of the head be part of the process (prolly a questoin for the shop doin the work)

I am not sure about the other seals but the copper seals or copper paintable seal would not melt and is used by many on other types of applications to compensate for the potential gaps between the heads.

[scotty914]

QUOTE

Are you talking about lapping the cylinder or the head?

well sort of both but i am sure most cutting happens on the heads, i would bet the actual lose of material in less than .0001.

QUOTE

I just think there has got to be a better way than removing material from the heads

not to perfectly mate the sufaces, if trying to remove major imperfections yes there is

QUOTE

For this particular application he is having his heads professionally refurbished and Luke is using new P&C's. Would the truing of the face of the head be part of the process (prolly a questoin for the shop doin the work)

yes the heads should be trued, and hopefully the cylinders are true too, but as some one in the other thread said it is like lapping a valve just to get a perfect seal

QUOTE

I am not sure about the other seals but the copper seals or copper paintable seal would not melt and is used by many on other types of applications to compensate for the potential gaps between the heads.

yes a copper seal would not melt but any rtv will burn over a short period. as for other engines using head gasket and rtv they dont have temps up to and over 350 degrees

once again the amount of material removed is less than you would remove with a piece of 600 grit sand paper

[Type 4 Unleashed]

QUOTE (Headrage @ Jun 27 2005, 05:07 PM)

When I rebuilt my motor I tossed the head gaskets and lightly lapped the head and cylinder with some VALVE GRINDING COMPOUND. Seems nice and leak free so far...

Lapping heads as with lapping valves, it's best to use a valve LAPPING compound, not a valve GRINDING compound. And I'am not talking symantics here, Cloves has valve lapping compound's, it's a double sided can with both a coarse and fine compound's, and the coarse is still finer than the valve GRINDING compound.
I, just recently needed some lapping compound, couldn't find any Cloves, as I need it NOW, but did find a source of some other brand, that was just to order.

Luke, I recommend, even though the cylinders are new, especially cause the cylinders are new, to have the tops trued, and have the cylinder lengths matched, REAMCO can do this, since your sending your heads there. Get a quote, before hand.

[echocanyons]

Please dont mistake what I wrote for using RTV or any silicone based sealant as a head gasket.

I did say that a paintable copper coat with or without the seal to make up for the imperfections would be better than removing material.

I do agree that if there are large obvious imperfections/damage that is should be addressed by machining, If the head wont seal anyother way machining is your only option right?

[echocanyons]

QUOTE

well sort of both but i am sure most cutting happens on the heads, i would bet the actual lose of material in less than .0001.

OK so lapping is more or less like polishing right?

I guess I was thinking that it entailed machining the face of the head.

[scotty914]

yup polishing is basicly like what you are doing, no real material removal

[nebreitling]

just make sure that your machine shop flycuts the heads well and insures that the tops of your cylinders are perfectly true. with that done, there should be no need to lap.

[LukeD]

Are these things Rimco will ask if I want or are they implied?

Do i Just Send them my heads And they call me with what needs to be done?

thanks

Luke

[anthony]

Does anyone know how the "carbon seal" Jake uses functions? I thought it was some kind of groove or bevel where the head and cylinder meet.

[Type 4 Unleashed]

QUOTE (nebreitling @ Jun 28 2005, 02:58 PM)

just make sure that your machine shop flycuts the heads well and insures that the tops of your cylinders are perfectly true. with that done, there should be no need to lap.

Has anyone, besides me, done a close inspection (magnafied inspection) of heads after they have been flycut?

It's, a cheap fast way to cut heads, and in all reality, it's not a quality job, and it's not the machinist, it's the flycutter, it's not a precision tool.

Thats why I perfer copper head gaskets, not only do they help seal cast iron and aluminum, there great for setting up compression ratios. I, set up a motor 1 time, and the piston stuck out of the cyl .020, and with copper gaskets I got the CR I needed. (IMG:http://www.914world.com/bbs2/html/emoticons/smash.gif)

CNC end mill, would be a nice quality way to cut heads, I can't aford that, so I use gaskets

So, lapping the cylinders, would be a benefit, if your not useing head gaskets.

This is my opinion, and others my disagree, even though there wrong. (IMG:http://www.914world.com/bbs2/html/emoticons/happy11.gif)

This is why I like this Club (IMG:http://www.914world.com/bbs2/html/emoticons/biggrin.gif)