601 heads. Going to run bigger valves, 2.02 and 1.6 if they fit. This exhaust is quite finished yet but almost there. These are going on top of my 4.030 4 bolt with a Lunati 60103LK cam, Edelbrock Performer EPS, Holley 650 or 700, not sure which I need yet. Yes, I know the compression is going to be quite high.


not the same one thats ported, but that is one of the ports I havent touched yet



Heres a few more pics of the other things Im doing to the car at the moment too. Some before and after stuff

 

Uhh.. I couldn't help notice a lack of valve guide boss in that port? Or is my eyesight failing me?

Car looks very sharp.

Ported 601's with lunati "best 268 cam ever" ? Sounds like a familiar combo Should be very hot. Go to 1.94"/1.6" valves. Cut the valve guides down, or run .050" offset keepers and shim it up. Pin the rocker studs, or swap to thread in ones. Will run like a bat out of hell.

Use the RPM intake, the EPS is just a selling buzzword.

 

yes, I cut the valve guide bosses all the way. My GN1 aluminum heads on my Grand National were cut like that as well. They put bronze guides in the heads and was all good. It made 554rwhp on 93 octane and a T70. Cam was a tad smaller than the lunati but "should" be fine
1 head is already pinned, gotta get the other done. :-)

 

oh ok, you will have bronze guides put in. That's weird, i've never seen anyone do that. Probably get pretty big exhaust ports as far as CC's go eh?

What type of drill bit are you using? I couldn't get through my studs, so I pulled them and tapped them instead. Just curious.

 

What type of drill bit are you using? I couldn't get through my studs, so I pulled them and tapped them instead. Just curious.

Its a bit of a pain. I just use normal CTC HSS drill bits but sharpen them often as required. (a lot) The drill rotational speed is critical as too much speed just burns out the drill cutting tip.
You get good after a while at the special hand technique needed to restore the cutting tip on a drill bit. I use a DA sander or a fat cylinder shaped stone to sharpen the bits by hand. A Drill Doctor is on the wish list.

It is time consuming and takes patience (and lots of drill bit tip sharpening) but is less time consuming than fixing a broken stud boss.
Once you've mastered the art of hand sharpening drill bits, its not that bad.

 

Hmm... I'd probably buy a pack of carbide bits or something from mcmastercarr or the like. I do have a pile of 3/32" bits and roll pins, so I might try that on the next set of heads, since I now have a drill DR. (went on sale a few weeks ago at CTC actually)

 

I didnt do the pinning job. I got these heads from a guy at work who was running them on a sprint car and 1 head was already pinned.
I almost have the 4 exh ports all done. Burned up my Dremel though with the flap sanding wheel so I have to get another one

 

Dremel? Wow, do you like to watch grass grow too? Time to step up to the big leagues with a die grinder, save yourself some time.

You'll have to post a picture when they put in a valve guide. I have never seen someone grind the valve boss completely out. Never.
Doing that to the intake port as well?

 

I am using my straight die grinder and my 90* die grinder to take the large amounts of metal out. I was using the Dremel to do the finish work. Will def post up an after pic with the guide.

 

heres a pic of my GN1 heads with no valve guide boss

gotta look close but you can see there is only the guide in the runner

 

Gn heads have the valve guide boss even the ones in the pic still have it... yes trimmed down but it is still there .... i doubt bronze guides will save it