www.the351cforum.com

ALL things related to the Ford 351C
It is currently Sat May 25, 2019 5:17 am

All times are UTC - 5 hours




Post new topic Reply to topic  [ 20 posts ]  Go to page Previous  1, 2
Author Message
PostPosted: Fri May 10, 2019 6:15 pm 
Offline

Joined: Tue Nov 06, 2012 10:23 am
Posts: 989
Location: Texas
Steve
Good numbers.

Im guessing the engine just didnt require the extra cfm. As for the 3310. I have always heard good things but the 2 I had, would run like junk on my 362C. Cam was not to radical it was a Wolverine hydo flat 290/290 218/218@.050 with .505/.505 and 110 lobe. Had Aussie 2v heads and a Edelbrock performer intake. Motor had 12" vacuum. 3310 would never run right. Always hard to keep the vacuum secondaries in tune and just never had the umph. I put a 650 Speed Demon on and everything changed. It will be a short period of time and i can bet your customer will ditch the 3310 too.
Matt


Top
 Profile  
 
PostPosted: Fri May 10, 2019 7:11 pm 
Offline

Joined: Mon Oct 23, 2017 9:53 am
Posts: 229
Matt I've always had good luck with 3310. I have a few here and they seem to just work. I also had my sons new in box 670 quickfuel but didn't get a chance to run. Would have been interesting to see difference. Nice little engine that was inexpensive and runs smooth. Learned a few things along way to so thats good. As many years as I've been around these cleveland motors and the old addage of bigger is better doesn't seem to apply here. This motor offers low end grunt and low rpm hp which most believe is non existent with cleveland.The class these guys are in they have to pull a certain vaccuum which they will meet so its all good.


Top
 Profile  
 
PostPosted: Tue May 14, 2019 9:50 am 
Offline
User avatar

Joined: Mon Oct 29, 2012 2:39 pm
Posts: 979
Good 3310 can work. I had a "3310" with a ProForm center. Loaned it to a friend with a Firebird 454 using an 850DP. He picked up a full 1 second in the 1/8 mile. Like to not got my carb back. Used to have a friend that worked on Q-jets - he could make a junky discarded Q-jet spank the hell out of a Holley on the dyno.

The only thing with the vacuum carbs is "flutter" on the secondary opening. Unless you are bracket racing, that is never likely to be an issue or even noticed unless something is really out of whack like way too light of a spring in the diaphragm. With a decent spring like a purple or stiffer, they even do OK on a bracket car. The DP carbs are very consistent but should be chosen wisely. The Falcon runs 7.60s - about 11.80s - and makes around 460 HP or so. Heavy car. If you just ask, everybody likely says "750 DP." The 650 DP on it runs the same ET and MPH as a souped up 750, so the 650 is what I run.

_________________
Chris - Merkel, TX
http://raceabilene.com/kelly/hotrod
"Owner built, owner abused."


Top
 Profile  
 
PostPosted: Tue May 21, 2019 8:16 am 
Offline

Joined: Mon Oct 23, 2017 9:53 am
Posts: 229
Dave i seen you and Dan did some testing years ago between airgap intake and some fpp dual planes. I also seen you tested a street dominator intake(2v intake) on 4v head and had your best results. Do think that's because of the The reversion in the 4v head?


Top
 Profile  
 
PostPosted: Wed May 22, 2019 3:56 pm 
Offline

Joined: Sat Dec 17, 2016 10:59 am
Posts: 15
DaveMcLain wrote:
Today I ran a 373 Cleveland on my dyno.

The intake is a stock Ford Boss 351 factory intake that somebody ground on a little bit to make a regular Holley carburetor fit.

The engine made peak torque of 435lbs/ft at about 3500rpm and 424 horsepower at 5900rpm. I was amazed that the engine managed to power peak that high with such a short duration camshaft. The customer wanted a very mild engine that will run well at low speeds using as many of the old parts as possible.


lol, the boss 351 is not a race intake... it has what many say are small runners. it's all that any 351c 4v needs under 6800 rpm on the street [aka a wide rpm power band]. For the record if people check the cross-section of that boss intake to the [so call BAD OEM] 1970+ 4v 'L' intake they are the same... one is AL versus Iron & one is setup for a square bore versus a spread bore.

Yeah I know I'm clueless... but when the mule* testing was done they [he] NEVER released the full dyno data on the 'L' intake... lol wonder why?

*iirc, the mule was a 392ish motor too


Top
 Profile  
 
PostPosted: Thu May 23, 2019 2:25 pm 
Offline

Joined: Mon Oct 29, 2012 1:52 pm
Posts: 548
830's are generally terrible and I'd be surprised if a 3310 wouldn't out run one every time.


Top
 Profile  
 
PostPosted: Thu May 23, 2019 5:37 pm 
Offline

Joined: Mon Oct 23, 2017 9:53 am
Posts: 229
Ive never had any luck with 830 either. Got one on shelf i never use. The dyno guy says he's had good luck. In the 830's defense it made a few more hp but not worth buying. Dave you've had good success with airgap also?


Top
 Profile  
 
PostPosted: Thu May 23, 2019 7:54 pm 
Offline

Joined: Tue Aug 01, 2017 9:50 am
Posts: 29
Just wondering when you speak for the Holley 830 being a bad choice are you talking about the annular booster model or the down leg model ?


Top
 Profile  
 
PostPosted: Fri May 24, 2019 8:20 am 
Offline

Joined: Mon Oct 23, 2017 9:53 am
Posts: 229
Mine is the annular booster NASCAR carb. The dyno carb was not the nascar series carb.


Top
 Profile  
 
PostPosted: Fri May 24, 2019 9:01 am 
Offline

Joined: Mon Oct 29, 2012 1:52 pm
Posts: 548
Either one is awful and the reason why is because the 830 is the opposite combination as the 950HP or the old 750 with an 850 base plate.

when Holley built the 850 model they went with a 1 9/16 venturi diameter which tends to greatly reduce the carburetor's metering signal BUT when they did that they also went with a larger 1 3/4 diameter throttle and what this does is help with the signal as well as the airflow through the carburetor. Using this big throttle baseplate on the body with a 1/38 venturi like the 3310 or 4779 works great because it gains airflow but also gains signal over a stock carburetor. This is a good way to go and it's what the 950HP essentially is along with a smoothed out body and a down leg stepped booster stock.

The 830 goes the other way. It gives you a big nasty venturi and it mates that with the smaller 1 11/16 throttles. This gives the carburetor very little venturi shape because the size is only expanding from 1 9/16 out to 1 11/16. The only reason the 830 is a "Nascar" carburetor was because Nascar made a rule that they had to use that combination. Otherwise on many tracks they would have run the 850 and or the 4779 just depending on what was needed from the combo. For a few years some teams were running 390's over the restrictor plates but then the rules were changed to require the 830 as far as I know.

With carburetors fuel curve trumps aiflow every time except for extreme cases and the 4779 combo has an easier time making that fuel curve be an effective one for the engine.


Top
 Profile  
 
Display posts from previous:  Sort by  
Post new topic Reply to topic  [ 20 posts ]  Go to page Previous  1, 2

All times are UTC - 5 hours


Who is online

Users browsing this forum: No registered users and 2 guests


You cannot post new topics in this forum
You cannot reply to topics in this forum
You cannot edit your posts in this forum
You cannot delete your posts in this forum
You cannot post attachments in this forum

Search for:
Jump to:  
Powered by phpBB® Forum Software © phpBB Group