StrikinLightnin

I have Hp500's that I purchased with Brodix heads.
The Shield under the intake has three tangs or tabs on each side.
When I pulled the intake one side of the shield had the tangs under the head
and on the other side the tabs were sitting on the bottom edge of the head.
How do you mount the shield on a stock hp500?
Seems odd that the tabs would sit on the intake portion of the head.
Wouldn't it keep the intake from getting a good seal?
I can't seem to get the tabs on both sides to go under both heads.
Athough if the shield was pushed lower I'm afraid it would interfere with the pushrods and lifters
If the tabs sit on the heads do you mount the intake gasket first then push the shield into place?
Or install shield then intake gaskets?
I know I'm doing something wrong and I need help to be sure I get it right!

Lmarth

It's been a long time, but I recall that with the black GM tray and GM intake gaskets that the tabs snapped down on the intake surface of the head and there were cutouts in the intake gaskets so the tabs didn't interfere with the gasket sealing. Not seeing your tray or knowing what gaskets your using,I can't help more. Just trying to help.--Lou

Pwrbt33

iTrader: (2)

Yup, he's right. The 3 tabs should rest on the intake side of the head. Most of your after market gaskets do not have cut outs for this pan. But there are some that do. If you are re-using the stock Dart intake you must use the pan, if not your engine will use oil at an alarming rate! Not a good thing. Some intakes use the pan because of the heat on the intake, and some dont use one at all.

Good luck !

Pwrbt33
Offshore Performance
1-877-GOFAST1
410-827-0200

StrikinLightnin

That's why I had so much trouble trying to get the intake installed last night.
I was trying to install the intake with Mr.Gasket which is what the builder had also used.
The Mr.Gasket doesn't have the cutouts for the tabs.
Unfortunatly I buggered up a couple of threads on the intake side of the head.
Going to try to helicoil the bad threads today.
I looked up the parts no. for the intake gaskets from Merc - 27-8181881
The gasket retails for $55.20 -Rediculious!
I think I'll use the Mr.Gasket intake gaskets and cut out the area for the tabs.

Lmarth

You just tipped over a rock I touched on last week having to do with helicoils. The jist of my thread was that manifold alignment had to be perfect or you'll be learning how to Helicoil. Decking the block and milling the heads required exact machining of the four surfaces of the intake/blower manifold. The front/rear intake gaskets seemed to pose the biggest challenge which is why a lot of builders use just Silicone on the front/rear (that's what Sterling used on both ends of my blower manifolds).My advice is to trial fit everything with several different gasket manufacturers and have an inventory on hand when you have a combination that works for you.--Lou

StrikinLightnin

I had one head resurfaced because of a blown headgasket.
'Guess I have a mismatch on my hands also.
Think I'll chase out bad threads today and WAIT until I get
the intake gaskets before I start to Helicoil.
The sad part of it is that the boat that I purchased had engines
done by a well known builder in the marine business.
The pan wasn't installed correctly which may have been part of
my problem with blowing a headgasket.
I'de like to put on a Brodix intake when I tear them down in the fall
and then maybe I can just throw that pan away!

Lmarth

You might just try chasing the threads. Those holes are on an angle and are tuff to do on the motor. Go easy on the torque. I think spec is 30 or 35 ft, lbs. (check the manual) Everyone makes mistakes,but some are hard to understand. If you're careful torqueing the bolts, you can often feel the threads starting to pull and stop until this fall when you can pull the heads.--Lou

Lmarth

Just reread my last post. As for making mistakes, I wasn't referring to you StrikinLightnin,but "the well known builder". I've chased those threads and suggest you find a bottoming tap. Your normal taps have a long tapered point which is fine for deep holes. The holes in your heads are relatively shallow. A bottoming tap has a flat bottom that allows you to---are you ready for this-- tap to the bottom of the hole before the tap bottoms out. Good Luck!--Lou

StrikinLightnin

I chased out all the threads with a "bottom" tap today.
Had to Helicoil three bad ones.
Some of the threaded holes are shallow and you have to cut down
on the helicoil or the tang will go out the bottom and then you can"t
snap it off - I found out the hard way!
With old gaskets I set and bolted the intake on loosely and the holes matched.
I must have gotten lucky with the air drill!!!
I need to get a set(or two) of intake gaskets and bolt everything
together without putting Ultraseal on the ends just to check.
If I can torque them up to 25ft/lbs I'll be OK until I can send them out
at season's end as suggested.

Lmarth

StrikinLightnin --Sounds like ya done good. I think you'll be just fine. Next time it's apart,make sure the mating surfaces of the intake are paralell to the head. Doesn't sound like you have much of a mismatch but I don't know what's been done to the block before. I had this problem many many years ago. Was running a little over 12:5 to 1:00 so quite a bit was off the heads/block. Had mismatch on intake and wound up with an intake leak. Was fine WOT(makes sense) but part throttle response/power was terrible. Was running a BBC in a Corvette at Watkins Glen and just held on to win the race. So you're not alone if that's any consolation.--Lou