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-   -   Inline 4 cylinder comp motor (https://classracer.com/classforum/showthread.php?t=21279)

SIX GUN 05-24-2010 12:47 AM
Re: Inline 4 cylinder comp motor
 
Intakes with plenums required very shallow floors and a lot of work to make power,.[/QUOTE]

I run an Inline 6, and I'm trying an old Holman/Moody singel 4 .... Should I try to raise the floor of the plenum ???The engine is a destroked 300 (272ci) Ford

Larry Fulton 06-25-2010 08:45 PM
Re: Inline 4 comp motor - Quad 4?
 
Not trying to steal this thread, but years ago I was told that the Olds Quad-4 motors were not legal in Comp. Eliminator...

Can anybody explain why not??

Thanks!

Tony Curcio 06-28-2010 06:51 PM
Re: Inline 4 cylinder comp motor
 
I'm going to guess it was because it had 4 valves per cylinder, and the rules didn't provide for them when the Quad Four first came out

Today, 4-valve engines are allowed in L/A and F/D with a weight penalty. They are still not allowed in F/ED.

Tom Simon 09-10-2010 07:29 PM
Re: Inline 4 cylinder comp motor
 
Quote:
Originally Posted by Bench Racer (Post 185337)
I am sure the inline 4's are a different animal than the aircooled VW's but the standard for the vw drag engines is the 48 ida's. with IR induction. There are several different performance manifolds options for the Bug engine that utilize a single carb ranging from a 2bbl, or a 4bbl setup. The single carb performance setup on a bug is normally only seen on a mild street car or in a racing class where rules call for stock carburation. I know a lot of the trends in car performance is spread by the monkey see monkey do thing, but when it comes to the quickest n/a aircooled VW's it will have 48 IDA's and IR manifolds. Don Jackson
That's true, the norm in the flat-4 world is ubiquitous Weber 48IDA (and derivatives there of) I have a 146cu in flat-4 2-valve VW (with IR) that makes >2hp/cu in. Not bad for an antique 2 valve motor conceived in the 1930's with 11" pushrods!

But the debate in the VW world isn't a clean one either, I know of two racers who have experimented with a common plenum on a NA flat 4 similar to mine, he claims to have found more bottom end torque. The went moot, when the organization outlawed plenum manifolds in the normally aspirated heads-up classes, pretty much halting further development.

ProStock bike? IR

Another point of reference is the NA or 'All Motor' Honda guys that raced in NHRA's (now defunct) Sport Compact Series. Whaen I raced with those guys, I mostly saw (if not every one) individual runner intakes on the All Motor inline 4 cylinders.

Mountainmotorman 10-29-2010 12:39 AM
Re: Inline 4 cylinder comp motor
 
Ask Aragona and you will know what it takes and what the issues are. LOL

Tom P 05-28-2011 11:06 PM
Re: Inline 4 cylinder comp motor
 
The 4 banger VW Bug's around here use much bigger Webers, 58mm i think.

norm saibene 06-02-2011 07:29 PM
Re: Inline 4 cylinder comp motor
 
they are 55mm on top and 45 mm on the bottom there only one guy that can get them to run on a 4cyl

Curtis Boggs 07-22-2011 02:26 PM
Re: Inline 4 cylinder comp motor
 
How about talking to Jake or Brett at Jenkins, .. aren't they responsible for Greco's 4 banger?

Curtis

Axis Racing 10-20-2011 12:38 PM
Re: Inline 4 cylinder comp motor
 
Hey Curtis,

How big is Greco's 4-cylinder in L/AA?

david ring 10-25-2011 08:13 PM
Re: Inline 4 cylinder comp motor
 
I think around 200 cubes-it is a specially built block.


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