Thread: cracked head or head gskt???

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I just put together a 305 using some reworked heads I haven't used before. On starting, the left exhaust is white and water is dripping out. There is no water in the oil and I don't see any bubbles in the radiator. Any way of knowing if I'm looking at a cracked head or head gskt/warped head? :
Craig

Yes, I used Blue RTV silicone on head bolts. Is this the right kind or should I've used a different sealer? Also, if I did use the wrong sealer, could I pull the bolts out one at a time , clean the bolts and reinstall with the correct sealer and not have to pull the heads and replace the head gskt? Any chance of this happining through the intake gasket & bolts?
Craig

that head may have a crack in the ex ports or like dennys said a leaky seat

I feel that the leak is on the intake side, seems to be running a little rough. Hard to tell, new engine-large cam. I built the engine on a stand so I know the heads are indexed right. Guess there is no shortcuts, time to pull the head and have tested.
Thanks for the help guys, Craig

RTV has no place on threads. I use teflon pipe thread paste on my head bolt threads because it provides lubricant for better torque values. Everything else threaded gets Aviation Form-a-Gasket. Water through the head bolts wont cause your problem, though, unless you already have a blown head gasket. Run the engine for a bit and pull the plugs. If you have as much water coming out as you say, one plug will come out cleaner than the others or yellow and that is the troublesome cylinder.

yes RTV works good for bolts. but i use stud some times they move abit when torque so they may brake any seal and with rtv. i think the teflon dope ropes in the stud or bolt better and never sets up. i use the aviation form-a-gasket to but i will not use the ARP thread sealer this stuff is not as good as teflon dope or aviation form-a-gasket

Originally Posted by pat mccarthy

but i will not use the ARP thread sealer this stuff is not as good as teflon dope or aviation form-a-gasket

Dammit Pat, now you've scared me. When I built my last performance engine over 40 years ago, the choices were simpler. Permatex or plumbers dope. Non-hardening Permatex was the easy answer. I've used RTV on the various stockers I've rebuilt through the last 40 years, but I'm a lot more concerned with how I put my 355 SBC together. I had decided on ARP lube/sealer on the open holes because of the following. ARP is a conscientious company. I figure the friction coefficient on the sealer has to be very similar to their plain lube. Therefore, torque readings would be more consistant. Consistant torque readings should lead to the least likelyhood of head gasket failure.

You have put together a lot of serious engines and along with some others on this list, I respect your opinions very highly. Are your feelings about ARP sealer based on multiple problems? Have others had bad experiences with it? Inquiring minds want to know!

Art

I may be old, but I still remember the zipper goes in front.

yes i have used the ARP on open head bolt deck blocks. I had is break down by the anti-freeze. they have a oil base to it .it seams that it just did not work as good as RTV or pipe dope or permatex with studs. all most all of the studs wick thru . i was not happy seening this.it was my engine i just rebuilt it and wash all the black sticky poop off (permatex) the studs and said to myself there must be something better? ARP thread sealer?.i will point out that studs can be a big pain in the back side and some time one or two may leak with permatex or with pipe dope .but just about all of them where leaking with the ARP i have gone back to permatex on studs and bolts or pipe dope.i have not seen any thing like that happen again . it may work for someone else ?but it did not work for me . so i can not tell someone to use it .i put the dope or permatex on the threads and then i put some 30 wt oil on the shoulder of the head bolt . i do things a bit deferent with studs. but this seam to work for me . and of coarse if it tells me to use molly then i will use that and not the oil . this is not to say ARP stuff is junk no. i think they make some fine fasteners but permatex hase been making sticky stuff longer and better

I just knew there was a reason I haven't put it together yet besides the weird weather we've been having in SoCal.

Art

well good luck. old man .use what make you happy. i keep a way from rtv on head bolts and studs but some guys use it and it works for them . on studs they move way to much to use it on them. the way i see it. i do not think it stick as good to the bolt like pipe dope or permatex i like to re tq the head bolts so i like stuff that will not take a set

Hey thanks for all of the information on thread sealers. Is that teflon paste the same as what plumbers use or is it like the Motormite threaded sealant paste. Also has anybody tried the Permatex Hi temp thread sealant?
Craig

My motor had RTV on the threads when I disassembled it. Coolant had obviously leaked past the RTV because the shank of the bolt was corroded. The head of the bolt sealed against the cylinder head so no coolant leaked into the engine. Most of the bolts were like this, so it wasn't just an isolated problem with one bolt.

The teflon paste is the plumber's stuff. I wouldn't worry much about high temp stuff, the head bolt threads shouldn't see more than 250 degrees. I think the teflon stuff is mostly rated to 400 degrees.