Jump to content

Recommended Posts

Posted

Thinking of stepping up from my 4 mill stock bore, aggresive dune port, to a clean up port cub. How much power increase should I see? I have been on a drag port cub, and it kills my stock bores, but never been on a clean up port.

Posted

[----------------------------------------------------------------------------------------------------------------------------------------] - that hard

Posted

Honestly a cleanup port runs like an out of the box cub.

It's kinda like the "Aggressive dune port" thing. Its more aggressive. Lol

Posted

There's not a lot of power to by found out of a 421 Cub with porting. You can probablly get more peak hp out of one, but it won't necessarily be faster at the track unless you have a super light rider/chassis. I dynoed one of my 421s and got 100 hp with a cleanup port with little tuning. Lots of tuning and with it drag ported (port timings probably not changed) and got 103 hp. Maybe could have got the 103 hp on the cleanup port with more tuning, but I was satisfied with it. The guy who ported it said it would take waaaaaaaayyyyyyy too much time/work to get the max hp out if it. I wanted it reliable, and lasting as well.It may have 5 hp left on the table, but it's not cost/time efficient, and would lose some reliability. You know the saying - the first 80% takes 20% of the time, the last 20% takes 80% of the time. JMO.

Posted

421 cub with no porting runs damn good from what i have seen.

But at the same time, i think my cub with the little bit of drag porting on it runs damn good too.

Mine ran high 4teens on methanol in stock uncut chassis with 250lb rider in 300'

 

What are you going to do with it? Strictly drag race it, if so and you are looking for every little ounce of hp, port it. Otherwise run it like it is. They run great both ways.

Posted

I have also done alot of research on this topic. I read through lots of posts and talked to many of the site sponsers. What I come up with is ya, the cub runs extremely hard with just a cleanup. All builders would drag port it but only some highly recommend it as a worthwhile gain for the price and work. The ones that were more for it, I felt maby had more R and D time with it and were more happy with the outcome. Don't get me wrong, all these guys know what they're doing and make some mean motors, they all just do it a little different. My verdict is a "fully blue printed comp drag ported" cub, will have significent gains over just a cleanup, when both are properly tuned and setup equal.

Posted

There's not a lot of power to by found out of a 421 Cub with porting. You can probablly get more peak hp out of one, but it won't necessarily be faster at the track unless you have a super light rider/chassis. I dynoed one of my 421s and got 100 hp with a cleanup port with little tuning. Lots of tuning and with it drag ported (port timings probably not changed) and got 103 hp. Maybe could have got the 103 hp on the cleanup port with more tuning, but I was satisfied with it. The guy who ported it said it would take waaaaaaaayyyyyyy too much time/work to get the max hp out if it. I wanted it reliable, and lasting as well.It may have 5 hp left on the table, but it's not cost/time efficient, and would lose some reliability. You know the saying - the first 80% takes 20% of the time, the last 20% takes 80% of the time. JMO.

 

I guess that backs up the fact that the Cub is cast as a drag port out of the box.

Posted

Mine runs pretty damn hard, trying to decide if I'm gonna get it worked on or just go to a bigger motor.

 

Im in the same boat as you right now.

Im just not ready to throw down the several g's its gonna take to knock off a .10 of a sec. Lol

Posted

Im in the same boat as you right now.

Im just not ready to throw down the several g's its gonna take to knock off a .10 of a sec. Lol

 

Exactly, I'll probably do a different chassis/alky before I do more motor work

Join the conversation

You can post now and register later. If you have an account, sign in now to post with your account.

Guest
Reply to this topic...

×   Pasted as rich text.   Paste as plain text instead

  Only 75 emoji are allowed.

×   Your link has been automatically embedded.   Display as a link instead

×   Your previous content has been restored.   Clear editor

×   You cannot paste images directly. Upload or insert images from URL.

Loading...
×
×
  • Create New...