 Making the type four rev higher |
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| Trekkor |
  Jun 10 2013, 04:55 PM
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#1
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I do things...  Group: Members Posts: 7,809 Joined: 2-December 03 From: Napa, Ca Member No.: 1,413 Region Association: Northern California  |
I have a VW Bug race car with a type four motor.
I would like it to safely rev up to 6500-7000 rpms. What is needed to accomplish this? thanks (IMG:http://www.914world.com/bbs2/uploads_offsite/fbcdn-sphotos-c-a.akamaihd.net-1413-1370904931.1.jpg) KT |
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| Mark Henry |
Jun 11 2013, 06:25 AM
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#2
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that's what I do! Group: Members Posts: 20,065 Joined: 27-December 02 From: Port Hope, Ontario Member No.: 26 Region Association: Canada |
There are limitations to what a pushrod motor can do.
Try a shorter stroke, but valve float will be your main problem. |
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| rick 918-S |
Jun 11 2013, 07:32 AM
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#3
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Hey nice rack! -Celette Group: Members Posts: 20,951 Joined: 30-December 02 From: Now in Superior WI Member No.: 43 Region Association: Northstar Region 
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QUOTE(Mark Henry @ Jun 11 2013, 07:25 AM)  There are limitations to what a pushrod motor can do. Try a shorter stroke, but valve float will be your main problem. (IMG:style_emoticons/default/agree.gif) Use math. Shorter stroke with a balanced bore size. Calculate the connecting rod ratio to determine what the projected RPM range should be. Lighten the rotating assembly to combat harmonic imbalance and the effects of inertia and increased effects of the weight as the parts start to fight the direction they are flying. Light weight valves, duel springs and fat pushrods that don't flex. That is the basics as I have learned and understand from my years in drag racing. That will get you to a high RPM engine. Making power in the upper range in a whole difference subject. |
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Posts in this topic
Trekkor Making the type four rev higher Jun 10 2013, 04:55 PM
ConeDodger Extreme balance. Light driveline components. Ignor... Jun 10 2013, 05:00 PM timothy_nd28 heavy duty valve springs and chrome moly pushrods Jun 10 2013, 05:02 PM The Cabinetmaker My 2056 has the raby valve train kit with stock sp... Jun 10 2013, 05:13 PM DBCooper All kinds of drag racers spinning them faster than... Jun 10 2013, 05:19 PM
ConeDodger
All kinds of drag racers spinning them faster tha... Jun 10 2013, 05:27 PM WLD419 Some might say the right combo :D , I would say ... Jun 10 2013, 05:26 PM Steve Do they make a 3/4 cam for a type 4?
3/4 cam has a... Jun 10 2013, 05:33 PM DBCooper
Do they make a 3/4 cam for a type 4?
3/4 cam has ... Jun 10 2013, 06:05 PM yeahmag A few key components:
* Aftermarket rods
* Caref... Jun 10 2013, 06:11 PM Trekkor This will be for endurance road racing.
I would li... Jun 10 2013, 09:22 PM mittelmotor That looks like the Buttonwillow ChumpCar race. Yo... Jun 10 2013, 11:52 PM Trekkor
That looks like the Buttonwillow ChumpCar race. Y... Jun 11 2013, 02:27 PM messix endurance racing? don't go for high rpm! t... Jun 11 2013, 12:11 AM Racer Chris My backup 1.8L race engine is set up for 6800 rpm ... Jun 11 2013, 07:06 AM WLD419 You should post this question over on the Type4 f... Jun 11 2013, 08:29 AM Trekkor I think our current set-up made 124hp.
Can't r... Jun 11 2013, 02:20 PM Trekkor It's a pretty fun car!
http://www.914worl... Jun 11 2013, 10:13 PM stugray
Is there a "rule of thumb" for con-rod... Jun 11 2013, 10:24 PM messix weight...
the longer rod will weigh more.
the is... Jun 11 2013, 10:42 PM Trekkor More fun:
http://www.914world.com/bbs2/uploads_of... Jun 11 2013, 11:04 PM Trekkor That's probably my biggest complaint with the ... Jun 11 2013, 11:41 PM Trekkor Dual Webers on the motor, BTW.
KT Jun 11 2013, 11:42 PM messix "floating the valves is not good!!... Jun 11 2013, 11:52 PM stugray
I thought that the problem occurred at the oppos... Jun 12 2013, 01:22 AM messix
I thought that the problem occurred at the oppo... Jun 12 2013, 01:27 PM r_towle You might want to consider a 915 tranny, or a prop... Jun 12 2013, 09:37 AM Mark Henry
You might want to consider a 915 tranny, or a pro... Jun 12 2013, 10:11 AM Trekkor Yes, maybe a 901 tailshifter with a flipped ring a... Jun 12 2013, 08:38 PM brant
Yes, maybe a 901 tailshifter with a flipped ring ... Jun 12 2013, 09:17 PM Trekkor
you don't have to flip it if you use a 911 ... Jun 12 2013, 10:01 PM DBCooper Just a general question, what's the history of... Jun 12 2013, 09:16 PM Trekkor
Just a general question, what's the history o... Jun 12 2013, 10:00 PM messix
Just a general question, what's the history o... Jun 12 2013, 10:11 PM aircooledtechguy If I build a motor to rev higher these are some of... Jun 12 2013, 11:13 PM messix and would you run it for 24hrs in race trim? only... Jun 12 2013, 11:45 PM DBCooper You said "we turned 322 3 mile laps in our 20... Jun 13 2013, 10:29 AM worn
Reason for the T1 suggestion was cost. All the ... Jun 13 2013, 10:45 AM DBCooper
What I think I am saying is that for power, I am ... Jun 13 2013, 03:04 PM Trekkor
You said "we turned 322 3 mile laps in our 2... Jun 13 2013, 01:23 PM yeahmag I would completely disagree from experience. My Ty... Jun 13 2013, 10:54 AM DBCooper Well, the T4 IS a truck motor, so it makes sense t... Jun 13 2013, 12:43 PM Racer Chris I averaged over 60 mph for 1000 miles the last tim... Jun 13 2013, 01:23 PM Trekkor We missed our class win by two laps.
We were doin... Jun 13 2013, 05:12 PM stugray
I drove my 914 back & forth from Oklahoma Ci... Jun 13 2013, 05:28 PM messix wow really guys :stooges: ... you cant compare cru... Jun 13 2013, 05:53 PM DBCooper That is SO cool. Well done. I don't know wha... Jun 14 2013, 08:10 AM sean_v8_914 you must manage the FORCE
force = mass x accelera... Jun 14 2013, 11:24 AM sean_v8_914 lots of cool valve float videos on youtube Jun 14 2013, 11:31 AM Trekkor better view of the duct work!:
http://www.914... Jun 14 2013, 12:37 PM DBCooper Wow, reinforced bumpers welded on, looks like disc... Jun 14 2013, 01:22 PM Trekkor Let's see if i can find some shots of the vent... Jun 14 2013, 01:42 PM Trekkor http://www.914world.com/bbs2/uploads_offsite/i944.... Jun 14 2013, 04:42 PM sean_v8_914 so I had to look at all teh pics on thet link, of ... Jun 15 2013, 10:08 AM sean_v8_914 that breather box is qustom HDR. the electrical co... Jun 15 2013, 10:13 AM Trekkor Exactly!
KT Jun 15 2013, 11:33 AM |
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