Anyone have any problem out of 8 bolt GN1's?

[faststkr]

I've done a search and there seems to be a problem with the 14 bolt GN1's but didn't see anyone mention cracking problems with the 8 bolt.

PLEASE give info on the al 8 bolt GN1's only.

 

[tazgn]

I had a set of the 8 bolt GN1's before the GN2's were out. I got them about 5 years ago. I had NO problems with them cracking. I had problems with bolt holes stripping out, but that's it. I got another pair of ported and polished GN1's about 6 months ago, and no problems at all. Oh, and HUGE difference in intake/exhaust runner sizes with the port job!!!! Now the felpro 1200's are almost too small!!

Derrick

 

[faststkr]

Thanks for the reply man looks like you have one bad azz ride there!

 

[GNSCOTT]

fastskr, The problemswith the 14 bolt heads was on an old casting. Champion recognized the problem and responded with a beefier 14 bolt head. Soon there will be some competition for Champion from TA performance. They are also developing a new alluminum head. Competition is a beautiful thing.

 

[faststkr]

What are the flow numbers out of the box for GN1 aluminum heads?

2. What are the flow numbers out of the box champion ported irons. I heard the out of the box unported GN1's flow more than the champion ported irons. If so how much more and what are the numbers please?

 

[750H.P.V6]

Champion Sucks

faststkr,

What you've been told so far is most of the story regarding the Champion Aluminum heads. In the 14 bolt configuration the early heads WILL crack around the additional 3 outboard bolt holes. This is because the castings are too thin in this area and they were mis-machined as well.

The earliest 8 bolt heads (prior to 1999) do crack also. They are prone to cracking around the end bolt holes under the valve cover. The end bolt is directly above the water passage from the intake manifold. Once again there is no re-inforcement in this area and they are mis- machined. When they crack they will leak coolant into the valve cover area.

As far as you question goes about flow #'s, a set of Aluminum Champion heads will flow in the neighborhood of 225 cfm on the intake and 160 cfm on the exhaust at 28" and .500" valve lift. It is also correct that these #'s are better than fully ported iron heads.

Neal