apexman

I have an LS1 Corvette FRC. I did a H/C late '04 early '05. I used a set of MTI stage 2e 853's heads. They were brand new. I primarily used this car for autocross and track day events. I was doing some gasket replacements as I had a small oil leak. I decided to pull the heads and inspect them as I had to replace my A/C compressor so I had a few things out already. I planned on cleaning them up and just replacing the valve springs. I found a hole in the intake port on ALL of them! Last dyno I was about 10%ish down on power. Made 425hp and 392tq originally and about a month ago 396hp 370tq on different dynos.

Anyway, I just was wondering if anyone else experienced poroblems like this with a hand ported head? From looking at the stock heads it looks like the bump in the intake area was ground down with maybe too much taken out?

photo below. Sorry so big. The holes all are in the same area and about the same size. I tried shing a light from the top so you could see the hole better.

apexman

I guess I should have asked if the holes were supposed to be there? I just didn't notice them when I put them on but that was yrs ago. I also didn't see them on the stock 853's.

apexman

looks like the bolt holes on the inside. Just never noticed the hole after porting. I am sure hardly anyone uses 853's anymore. I tried a search and didn't come up with anything.

Randy WS6

iTrader: (69)

Yes, this in normal for ported heads, That from the rocker arm stud boss. Just put some loctite on the rocker arm studs and youll be fine. My self. after i torqued down my studs, i took a die grinder and ground down the stud that was exposed in the runner to make a smooth air flow.But thats if you use aftermarket studs not the stock rocker are bolts and with the heads off the engine..

Schwanke Engines

iTrader: (1)

Those are the holes for the rocker arm bolts. As long as you used thread sealer when you installed the intake rocker arm bolts, they are fine. If you didn't, you might have a slight oil consumption issue.

apexman

Thanks guys. I haven't had an oil consumption problem and always use loctite!

Thanks for confirming.

anheuserbusch08

iTrader: (11)

i just ran into some MTI stage 2e 853 heads for 200 bucks just valves and heads but these valves are huge!!! i wonder what size they are? from what i see they look like stainless and feel like theyre hollow stem because theyre lighter than the stock valves

apexman

My Stage 2e's have 2.02 intake valves and 1.56 or 1.57 exhaust I believe. They are worth way more than 200 bucks. If you are running a mid size cam with these heads you should see decent results on a serious budget.