SneakyPete

I have been chasing a leak on my intake for some time. Last year I had vortec heads and an RPM Air Gap on my 383, no problems. This year I changed to new AFR 180 Elimantors and a new Victor Jr. I had it out for about 5 mins and stopped to check the motor and oil was boiling out of the breather and back of the valve covers. Before this I had it running on the trailer for approximately and hour with no poroblems. I assumed it was the intake gaskets because at one point before I fired the motor I pulled the distributor back out and noticed a little coolant on it. I changed the intake gaskets and let it idle on the trailer and noticed it was surging, and it was sucking air between the head and intake near #6 and #8. I didn't notice any coolant leak, and I pressure tested it and it held 15psi, but after letting it sit I noticed pools of coolant sitting on the front of the intake by the rear bolts on the front coolant passage. I don't see how it could wick up the bolt and collect there, but I couldn't see any leak from the thermostat. I haven't changed the gasket again yet, but I noticed my ARP bolts had 8 bolts that have short fat heads, and 4 that have tall skinny heads, with corresponding smaller washers. Where do these 4 go? I am going to use Fel Pro 1266 (.120 thick) intake gaskets this time around. What do you think I am doing wrong, and what should I be doing to fix the problem? The block has been decked, but I don't know how much. Like I said, there was no problem last year with the Vortecs. The season has been a wash for me with this problem, I have only got 5 minutes on the water this year with the boat. I haven't pulled a valve cover, but they are new heads, new head gaskets, and torqued properly. The motor is not reverting, I have pulled the riser immediately after running and found no traces of water.

BillK

az,
The eight bolts with the smaller washers are for the corners around the water passages. On most intakes (but not all) the holes are very close to the water passage and there is not enough flat surface for the large washers to seat properly. On some manifolds, there is enough room that it really does not matter where you put them.

That being said, I dont think having them in the wrong place would cause the problem you have. One thing to check is if any of the bolts are bottoming out. I had a set of heads a long time ago that did not have the corner holes drilled deep enough and the bolts would bottom out. I caught it when tightening them , they just felt strange.

Bill Koustenis
Advanced Automotive Machine
Waldorf Md

SneakyPete

Thanks for the tip. One of my buddies said the same thing, just wanted to cover all of my bases. I actually have 2 ARP bolt kits, do you think if I used the both sets of washers that would take out enough slack, combined with the thicker gasket?

stevesxm

bill is right. my process was to be able to screw all the hardware in by hand without washers and gaskets and make sure they seat. then WITH gaskets and waskers they are sure to have clearance. as he notes, a lot of times you end up just catching the unfinished threads ast the bottom of a blind hole and they FEEL like they are tight but they are not. this is common on aftermarket heads

Griff

Are you torquing the intake manifold bolts down in the proper order and in gradual steps and to the right ft/lbs?????
Also, some of the intake bolts go into water jackets and you should use some thread sealant.

SneakyPete

Thanks guys. The first time I did it, I used the proper sequence. The second time I did it I was in a remote location and didn't have internet or the instructions, so I ended up using a criss-cross pattern, which I am sure didn't help things. What do you guys use on the gaskets, rtv around the coolant ports, and maybe some gaskacinch around the intake ports, on both sides of the gaskets?

ohmthis

Are you using Stainless bolts on the intake? These don't hold torque real well and can loosen up. Even if the engine has only been running a short time. I only use RTV for the the front and back of the block to intake seal. I use teflon tape on the bolts that run into the water passages and I check the torque twice when torqin down the intake. Good luck, I've been chasing down demons all season too.
Anthony

Griff

Don't use rtv except for maybe a very thin coat to make the gasket stay in place. It will actually act as lubricant and allow the gasket to push out when tightened.

SneakyPete

I am using the black oxide bolts. I used quite a bit of RTV the second time. Should I put them on dry or use Permatex #2? I am going to clean the snot out of the surfaces and bolt holes with brake clean and put plenty of thread sealer on the bolts.

Griff

Let the gasket do its job. It should seal fine when installed dry. I prefer to use something tackky to hold them in place. I prefer the Fel Pro permatorque gaskets.