Don Terrill’s Speed-Talk

New to the forum,
I had a valve failure in my 565 that ruined one Dart 335 cnc head. I've looked for a used casting with no luck and 4600.00 for a new set is not in my budget at this time.
Does anyone have any experience/advice with some of the cheaper Chinese castings on the market, pros and cons, make good power? Thanks!

Are you sure the head can't be repaired?

If it’s Aluminum it can be fully repaired for far less then 4600!

I hope you install top shelf valves this time around even if you have to spring for new heads, that is if the distruction was the valves fault in the first place.

As long as the valve job is good and you can go some porting in spots on those import heads they should work ok, not as good as a Dart or AFR's and you might be down a little hp but the price sure beats the death out of $4600.

I talked to a few people about having it fixed and all said it could be repaired but with problems. I guess the seats staying pressed into the head after the TIG welding process is a issue.

I'm pretty sure it was a valve that let go. I bought the Dart 335 heads from Shafiroff back in the early 2000s and they still had the original valves that were supplied from Shafiroff.

Ghost-Writer wrote: ↑Sat Aug 06, 2022 10:35 am I talked to a few people about having it fixed and all said it could be repaired but with problems. I guess the seats staying pressed into the head after the TIG welding process is a issue.

I'm pretty sure it was a valve that let go. I bought the Dart 335 heads from Shafiroff back in the early 2000s and they still had the original valves that were supplied from Shafiroff.

We fix some pretty messed up stuff.. if they are worrying about the seats.. bring it somewhere that knows what they are doing. Most times the seats and guide come out, then you weld, peen, remachine the counterbore, etc.

Show us some pics.

You need to find a new repair shop if they are telling you they can't be fixed or will have issues. I've seen heads so badly damaged you'd think they were scrap, completely repaired, good as new. It takes someone who knows what they are doing and a good machinist but they are definitely repairable....

I will get some pictures next weekend the heads are at my friends shop.

Dart said they can repair the chamber but the price to fix it was almost the cost of a new casting. I really didn't want to spend that money on a used head and have problems with it down the road. If anyone knows a good repair shop I'm willing to listen? Regards

couple of pics

Dart cnc heads flow very close to the as cast but the cnc outsells them by a huge margin.

Wow, that's pretty nasty, but it can be fixed.

If only the one head is munched, buying just one casting should be well below $4,000. Or as just mentioned, an as cast version of similar size should save some coin and a little pocket porting and port matching should get it close to the other. Just a thought. Trying to think outside the box if I were in your shoes and strapped for cash. I would think it would be the same or less than buying a pair of overshore castings.

Paul

I would look for someone else who had a blow - up and may have one good head. Even if its a different brand. Beggars can' be choosers as my grandpappy used to say.

For $4000+, you could buy a used TIG welder and all its accessories, take a high school night class in welding and fix it yourself in a month or two! Then you won't be at the mercy of others next time life goes sideways on you. Anyone that runs & tunes a big big block Chev should be capable of doing this- and maybe should expect to! Unless you're racing for money instead of paying to go down the track, take the time to fix it right. Your own TIG is a future investment.