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by hoffman900
Mon Oct 18, 2021 7:02 pm
Forum: Engine Tech
Topic: NASCAR Tri-Y dimensions
Replies: 1
Views: 289

NASCAR Tri-Y dimensions

Can anyone share?

Looking for primary diameter / lengths (and steps), secondary lengths / diameters (some seem to step or taper?), choke, and collector size. Typical port length would be helpful too.

I can see some of them from eBay postings, but missing a few critical dimensions.

Thanks
by hoffman900
Thu Oct 14, 2021 2:48 pm
Forum: Engine Tech
Topic: Guys who CNC port
Replies: 21
Views: 1413

Re: Guys who CNC port

We have our own A560 Centroid in house and cnc port heads for many other shops. Once in a while someone wants us to copy their master ports, make the program, and run it exclusively for them. We absolutely respect their wishes. I believe that it would be more difficult to prosecute someone for copy...
by hoffman900
Thu Oct 14, 2021 11:45 am
Forum: Engine Tech
Topic: Guys who CNC port
Replies: 21
Views: 1413

Re: Guys who CNC port

We have our own A560 Centroid in house and cnc port heads for many other shops. Once in a while someone wants us to copy their master ports, make the program, and run it exclusively for them. We absolutely respect their wishes. I believe that it would be more difficult to prosecute someone for copy...
by hoffman900
Thu Oct 14, 2021 11:41 am
Forum: Engine Tech
Topic: Dyno Racing
Replies: 11
Views: 822

Re: Dyno Racing

I know this isn’t a griping thread, but as a spectator, I really lost all interest after they neutered the series after 2013. The vintage class was interesting up until the Smithberg/Adams Hemi and Kaase Y Block, but again, that was neutered as well.
by hoffman900
Tue Oct 12, 2021 2:32 pm
Forum: Engine Tech
Topic: Unique Engine – More Power Needed
Replies: 26
Views: 1538

Re: Unique Engine – More Power Needed

Individual runner carbs are much more sensitive to cam timing and the exhaust than carbs with a plenum between them and the cylinder.
by hoffman900
Sun Oct 10, 2021 4:49 pm
Forum: Engine Tech
Topic: Lobe Intensity vs Durability
Replies: 45
Views: 1692

Re: Lobe Intensity vs Durability

Absolutely. :lol: Not trying to be difficult or preachy either, but you can see why it's actually a difficult question to answer correctly. Not taken that way in the least and it's all appreciated. As for the difficulty, it's plain to see. Despite the science and the math that goes into a given des...
by hoffman900
Sun Oct 10, 2021 3:44 pm
Forum: Engine Tech
Topic: Lobe Intensity vs Durability
Replies: 45
Views: 1692

Re: Lobe Intensity vs Durability

Will be interesting when Mike chimes in. It will. As I mentioned those are Jones' profiles. I have to rely on the experience of others unlike the petroleum engineer come camshaft grinder who did it all. Some off the shelf lobes are bound to suit my modest goals but as any hot rodder, I don't want t...
by hoffman900
Sun Oct 10, 2021 3:27 pm
Forum: Engine Tech
Topic: Lobe Intensity vs Durability
Replies: 45
Views: 1692

Re: Lobe Intensity vs Durability

It's just not that black and white from my experiences. This I'm learning. Case in point is what I have compared to what I need for a change in application and that answer doesn't appear easy to come by. An engine is a complex system with everything having an effect on something else. It's amazing ...
by hoffman900
Sun Oct 10, 2021 11:14 am
Forum: Engine Tech
Topic: Lobe Intensity vs Durability
Replies: 45
Views: 1692

Re: Lobe Intensity vs Durability

Looking at Cam Dr. I'm not sure if it's the stuff of the hobbyist. Which is what I am. That doesn't mean I don't appreciate all of the science. I'll look into it further. That said, one excellent explanation with respect to ratio vs lobe lift I've come across was posted by CamKing . Ignoring lobe d...
by hoffman900
Sat Oct 09, 2021 3:14 pm
Forum: Engine Tech
Topic: Lobe Intensity vs Durability
Replies: 45
Views: 1692

Re: Lobe Intensity vs Durability

What I have learned in those numbers don't tell you really how it's going to impact the valvetrain. You need someone who knows what they're looking at to see the derivatives (Cam Doctor level at least). Plenty of old school, low intensity cams out there that actually have crazy acceleration and jerk...
by hoffman900
Wed Oct 06, 2021 11:31 am
Forum: Engine Tech
Topic: Fiat twincam project coming off the stand
Replies: 28
Views: 1831

Re: Fiat twincam project coming off the stand

Remind us what’s the highest redline rpm you’re comfortable with? I have cast pistons. I think I could occasionally hit 7800rpm. I was hoping the bigger cam would lift the torque curve up a bit all along, not just at the very top rpm. The bigger cam has about 10deg more duration at 0.050", only abo...
by hoffman900
Thu Sep 30, 2021 3:43 pm
Forum: Engine Tech
Topic: Naked Ti rods
Replies: 3
Views: 482

Re: Naked Ti rods

piston guy wrote: Thu Sep 30, 2021 2:41 pm There is a coating company in Valencia (Ca) that does DLC coating on ti valves. Can't remember the name but they do them for DelWest.
https://actechnol.com/automotive/ ?
by hoffman900
Wed Sep 29, 2021 10:48 pm
Forum: Engine Tech
Topic: Dimpling a LS port
Replies: 106
Views: 3906

Re: Dimpling a LS port

Here is how Honda quantified it: 3AAFAA45-E64C-49F4-865D-689A692A7135.png 2C13CF35-9374-4FAC-8970-BFC14009DC1C.png I have no doubt what they did works well as it in many ways emulates what a carb does inherently. I wonder how important is it to run the really high fuel pressures compared to running...
by hoffman900
Wed Sep 29, 2021 7:59 pm
Forum: Engine Tech
Topic: Dimpling a LS port
Replies: 106
Views: 3906

Re: Dimpling a LS port

Here is how Honda quantified it:
3AAFAA45-E64C-49F4-865D-689A692A7135.png
2C13CF35-9374-4FAC-8970-BFC14009DC1C.png
by hoffman900
Wed Sep 29, 2021 7:29 pm
Forum: Engine Tech
Topic: Dimpling a LS port
Replies: 106
Views: 3906

Re: Dimpling a LS port

The question I was asking was is there any data that shows the fuel injection actually cools the same or better? I’m not after some theoretical recipe or whether fuel injection shower vs port injection makes more power as that’s not new information. I’ve seen many times throttle body injection prod...