Opps, left out head dowels. Problems?

[89_turborunner]

So I made another mistake. I put the head on the engine without putting the two little dowel pins in that help locate the head on the block. I can think of two reasons toyota put those pins in the block:

1: So you can correctly place the head on the block before you install the head BOLTS.

2. Because they are necessary to locate the head relative to the block, even when used in conjunction with head STUDS or BOLTS.

My setup- Rebuilt bottom end, milled block and head to RA between 5 and 10, ARP studs with 30wt oil, torqued to 120lb*ft on a 2mm cometic MLS.

Do I nead to tear the whole thing down and replace those dowels?

 

[1988SupraDreams]

I have no idea in answer to your question, but man... It'd suck if you had to rip it apart again...

 

[supradavenz]

lol hmm think i did this aswell actually engines just past 2500kms and took it drag racing last night and still runs sweet.. lol let you know if it dies...

 

[mkIIIman089]

hrm... although the studs would hold it in pretty close I'm betting those dowels were a much more precise aligning tool. Especially after a lifetime of heat cycling the thing.

 

[cjsupra90]

you need the dowl pins. dont risk it, put them in

 

[89_turborunner]

NOOOOOOOOOO!

Has anyone installed ARPs without removing the cam before?

And do I have to do anything with my head gasket now? or just slide in the dowels and don't touch the gasket?

 

[mkIIIman089]

I suppose that would depend on wether or not the coating on it needs heat to glue itself in. Which I'm betting there is a good chance it does, so you could be in the clear and not have to do anything.

 

[Yeahdoug]

You could run into headgasket problems. My buddies did the exact same thing on his car.

 

[89_turborunner]

You could run into headgasket problems. My buddies did the exact same thing on his car.

Left out the dowels, and then he had problems? Or he took apart the head and block and ran into sealing problems? more info please.

 

[pimptrizkit]

i couldn't see it as a huge problem..

but if you dont have the motor off the stand yet then i would yank the head and do it right, hate to see an oil passage blocked or some thing stupid..

now if that was a dowle for the tranny i would say you fucked up there and it has to go in..

i have heard of people losing to bearings tranny bearings and crank beariunga from mis-aligned trannies.

 

[sponsored1]

You NEED the dowels. They align the head and block. They head can still move slightly without them in. With the multiple heat cycles it goes through and the cylinder pressures, the head will actually move a little bit if the dowels arent in there. Each time it moves it can scratch off some of the coating from the headgasket. Whats likely to happen is over time you will start leaking coolant. Also, youll need to remove the head completely as the dowel pins normally need to be knocked in with a hammer as its an interference fit.

 

[johnathan1]

The dowel pins also align the head gasket when you first put it on...without it, it could be on slightly wrong, and not seal at all. :icon_conf

 

[89_turborunner]

Last night I decided to move on without installing them. Now the turbo is on, brackets, fuel rail, etc.

How coult those two dowerls locate the head more precisely than 14 studs?

and will someone please answer this question: IF I REMOVE THE HEAD, WILL THE VITON COATING STILL BE OKAY?

 

[Stretch]

The coating will be a little flatter, as in if it had any raised rings around passages they would be squished from you torquing it down. If you didn't spray gasket goo on it tho, and didn';t scratch it by sliding the head around while putting it on, then the coating should still be mostly fine. Remember, you never ran it so it never even got hot or anything yet, it's still cold and fresh. Like an Atlantic Salmon!
eric

 

[TurboStreetCar]

i did the same thing, over the course of my funds time limited 2 year build it slipped my mind, remembered it 3 days later while it was still on the stand pulled the head off, popped them on and the coating was fine. im running a cometic 2mm with arp's.

 

[veedubin]

To he who asked about ARP's with cam in answer.......yes I do think you mean studs?? I just did my HG last night with ARP studs cams in, block in car! it worked word of advice put washers in first!not after stud is through head

 

[89_turborunner]

Ok I called my friend's dad... Whom I would consider an authority on engine rebuilding. He said leaving them out is a no-no. I took the whole thing apart and the viton coating on the gasket looked fine, it is back toether, and I got the manifolds and wiring harness (mostly) on it. And since everyone loves pics,

 

[mkIIIman089]

Gee... why did you even bother asking on here? EVERYONE told you to put them in, then you deicde not to until you call some guy and HE says put them in? LOL

 

[jdub]

What torque did you use when you tightened down the ARP studs?

 

[Zach]

I decided....

How coult those two dowerls locate the head more precisely than 14 studs?

Deciding was your first problem. There was no decision to make, just do it right and forget about it.

Those two dowel pins locate the head more precisely than 14 studs because of very tight tolerances around the pins. There's a little bit of room around all your head studs, but no real room around the dowel pins.