|
Author
|
Topic: 351W questions
|
Jerry Piner
Gearhead Posts: 257
From: staunton, va
Registered: Dec 2001
|
posted 12-14-2001 11:11 AM
 
I bought a 68 mustang this summer. The car was built about 11 years ago. It has a 351w 9:5:1, crane 302 solid lift cam 244/252 @50 553/572 lift, roller rockers, an old Holley single plane street dominator, the heads were suppose to ported some, 750 holley double pump, headers, amd 2.5 inch 2 chamber flowmasters. It has a C6 with shift kit, and the guy told me a 3000 stall, it only stalls at 2200, 4.11 gear, and i run 275/50/15 BFG drag radials. I race it in the street class, at the end on the year it was running low 8.40's @85-86mph with sixty foot around 1.98 in the 1/8th. The car runs good but i feel it could run better i think it has a severe case of mis-matched components. i was looking for suggestions of what i should change and what i could expect out of the car. A couple of things that have been mention to me, is a 4.56 gear, edelbrock preformer rpm, carb spacer, and either an 850 or even a 950 holley. just wondering what everbody thought.
|
Moneymaker
Administrator Posts: 29200
From: Lyons, IL, USA
Registered: May 99
|
posted 12-14-2001 11:26 AM
Welcome to M&M Jerry  !
A 4.57 gear and a good set of tires would do wonders. No other change will give you more bang for your hard earned bucks. To check actual stall manually put the car in high gear and hold the brakes as tight as you can. Then floor it momentarilly and note the RPM achieved. That is your actual stall.  ------------------
Alex Denysenko
Co-Administrator and Moderator
NHRA/IHRA/SRA member
NHRA and IHRA SS/LA National Record Holder '00 & '01
Fleet of FoMoCo products
Moneymaker Bio
US Class Nationals link
|
kid vishus
Gearhead Posts: 7251
From: middle of NC
Registered: Oct 2000
|
posted 12-14-2001 11:35 AM
Welcome to the best site on the web Jerry
Glad you found it without much trouble. Since I'm a Cleveland guy, I'll let the other more knowledgable folks answer your question.
--------------------
Rob Hetzler
'69 Mustang fastback
9.97 @ 135 all cleveland, all Ford
|
steve'66
Gearhead Posts: 9835
From: Sonoma,CA,USA
Registered: Mar 2000
|
posted 12-14-2001 11:40 AM
Welcome to M&M Jerry! What heads are on it? The stockers are the achilles heal of a 351w. The mismatched parts, heads/intake/cam are fighting each other. Your gear and converter are too low for the cam & intake and not tall enough for the heads. If you want to spend $$$ upgrade the heads, gear, converter, and tires. And let her rip! SteveW
|
Rustang
Gearhead Posts: 880
From: Clarion PA
Registered: Nov 2000
|
posted 12-14-2001 03:32 PM
My combination was very close to yours: Street dominator intake, 750 vacuum secondary, 1969 heads mildly ported, .030 351W, cam was a solid 252/260, .571/.591, 108 lobe centers. compression 11.5:1, c-4 at 3500 stall, 4.33 gears. With 28x9 slicks it went 11.18 in a 3200lb '67 mustang. Here's where there may be some differences: what is your cams lobe center? car weight? C4 is worth a couple tenths over the C6. If you don't want to invest in another trans, send your existing torque converter out and get it loosened up. (That one item alone took me from 1.88 60' to 1.60's.) Also, I ran the street dominator because it was all that was avail at the time. Mine was HEAVILY ported by a guy that new what to do to this intake. I'd recommend going with the Victor Jr. I bolted one on untouched and didn't loose any ET over the heavily ported Street Dominator. Bumping up the compression will help too.  ------------------
http://www.rustang-racing.cityslide.com/contents/contents.cfm/712231
'68 mustang 351 clevor- 10.92@124
'67 Stang, 351W -11.18@118
'69 351C Torino-14.90@100
'78 Pickup 351W-15.56@88
'79 Pickup 460 ET=??
|
Jerry Piner
Gearhead Posts: 257
From: staunton, va
Registered: Dec 2001
|
posted 12-14-2001 04:08 PM
Hey Rustang, did you have any hood clearance problems with the Victor jr? And exactely what does loosen a convertor up mean??
|
Moneymaker
Administrator Posts: 29200
From: Lyons, IL, USA
Registered: May 99
|
posted 12-14-2001 04:24 PM
Increase the stall speed. ------------------
Alex Denysenko
Co-Administrator and Moderator
NHRA/IHRA/SRA member
NHRA and IHRA SS/LA National Record Holder '00 & '01
Fleet of FoMoCo products
Moneymaker Bio
US Class Nationals link
|
Rustang
Gearhead Posts: 880
From: Clarion PA
Registered: Nov 2000
|
posted 12-14-2001 07:30 PM
I didn't have any hood clearance problems after I cut a hole in the hood! I was running a 5" snorkel, but I don't recall how close it was to the stock hoodline------------------
'68 mustang 351 clevor- 10.92@124
'67 Stang, 351W -11.18@118
'69 351C Torino-14.90@100
'78 Pickup 351W-15.56@88
'79 Pickup 460 ET=??
http://www.rustang-racing.cityslide.com/contents/contents.cfm/712231
|
n2oMike
Gearhead Posts: 3058
From: Spencer, WV
Registered: Jan 2001
|
posted 12-14-2001 08:57 PM
That engine has too much cam.Stock heads + street dominator + 9.5cr = around 5500rpm. To match the camshaft to the rest of the engine, you'll need something not exceeding 230 degrees @ 0.050" on the intake. That engine has around 15 degrees more than it needs. A smaller cam will give the engine tons more midrange, and will make the car MUCH more responsive on the street, and will power it to FAR greater 60ft times. Good Luck! ------------------
Mike Burch
66 mustang real street
302 4-speed 289 heads
10.63 @ 129.3
http://www.geocities.com/carbedstangs/cmml_mburch.html
http://www.fortunecity.com/silverstone/healey/367
|
Rustang
Gearhead Posts: 880
From: Clarion PA
Registered: Nov 2000
|
posted 12-14-2001 10:34 PM
I think that cam, depending on the lobe center and how good the heads have been ported, will work fine with a little bit of sorting out the combination. Increased compression, a better intake, and higher stall speed should have dramatic affects. I'm no pro, this is just based on my past experience. My combo described above,the first year out, only went 12.70's. All I did over the winter was increase compression, more stall, and an intake change and that gave me 11.70's first pass of the next season. 6800 rpm shift points. ------------------
'68 mustang 351 clevor- 10.92@124
'67 Stang, 351W -11.18@118
'69 351C Torino-14.90@100
'78 Pickup 351W-15.56@88
'79 Pickup 460 ET=??
http://www.rustang-racing.cityslide.com/contents/contents.cfm/712231
|
74merc
Gearhead Posts: 1322
From: Demopolis AL
Registered: Jun 99
|
posted 12-15-2001 04:47 AM
how's it tuned? a 3500 stall that engages at 2200, either its a mismatched stall, flat out wrong numbers given to you, or the engine may be weak on the low end and not slipping the converter...
or am I wrong here guys?
|
kid vishus
Gearhead Posts: 7251
From: middle of NC
Registered: Oct 2000
|
posted 12-15-2001 07:55 AM
quote:
Originally posted by 74merc:
how's it tuned? a 3500 stall that engages at 2200, either its a mismatched stall, flat out wrong numbers given to you, or the engine may be weak on the low end and not slipping the converter...
or am I wrong here guys?
It is hard to find the true stall of a convertor without a transbrake. The way Alex said is the only way to do it. Jerry might only be able to hold the car with the brakes to 2200 even though the convertor will really stall 3500. I had a convertor in my street car that had been behind a transbrake in the racer, it stalled 4800 in the racer, even though the motor combo was a little different, I could only hold it to right around 3000 with my drum brake system.
|
Rustang
Gearhead Posts: 880
From: Clarion PA
Registered: Nov 2000
|
posted 12-15-2001 08:17 AM
Converters are not a one-size-fits-all deal. That's the problem with buying one "off the shelf". It may be advertised as 3000 stall, but it is going to stall higher against a big block compared to a small block. In the case of a C6 converter, the manufacturer could be trying to accomodate everything from a 289 to a 460! The trick is to match the stall speed rpm with the max torque of that particular motor. My feeling is if Jerry's car really is stalling at 2200, he's giving up a BUNCH of ET.
To verify stall speed, the method that has worked best for me is to take the car out on the street and coast along about 10mph with the trans in 3rd gear. Then from a dead idle, nail the throttle and observe on the tach at what rpm the car "jerked". That should be your actuall stall speed. This was the method recommended to me by ATI and TCI. Just powerbraking the car setting still will not give true stall speed, you have to have the throttle mashed.
For around $100-$200, usually the mfg. will adjust the stall for you based on what your combination is.
|
Moneymaker
Administrator Posts: 29200
From: Lyons, IL, USA
Registered: May 99
|
posted 12-15-2001 12:18 PM
I do not believe that the cam is too big either.
My method of checking the stall is full proof! especially with a tell tale or memory tach.
Last time I checked flooring it was the same as mashing it, only in different parts of the country. ------------------
Alex Denysenko
Co-Administrator and Moderator
NHRA/IHRA/SRA member
NHRA and IHRA SS/LA National Record Holder '00 & '01
Fleet of FoMoCo products
Moneymaker Bio
US Class Nationals link
|
Rustang
Gearhead Posts: 880
From: Clarion PA
Registered: Nov 2000
|
posted 12-15-2001 01:16 PM
Alex, now that I stop and think, your stall test should work because high gear shouldn't overpower the tires. Where I work, we manufacture diesel-powered equipment, and we test stall speed of converters the same way you describe. The only difference is we have industrial transmissions and coolers that enable us to stall the converter for 5 minutes!
Maybe the reason the converter mfg's recommended the method I described was for cars that can not be put in 3rd when they're sitting still??signed,
The Masher
|
Moneymaker
Administrator Posts: 29200
From: Lyons, IL, USA
Registered: May 99
|
posted 12-15-2001 01:53 PM
The main reason the convertor manufacturers do not specify my method all of the time is that not all of the customers have full manual control valve bodies Rustang. With a street and strip "automatic control" valve body you have no means of placing the car in high gear at rest like you do with a full manual. In that case your method can give you an idea but is not as precise as the high gear standing still "mash" method. ------------------
Alex Denysenko
Co-Administrator and Moderator
NHRA/IHRA/SRA member
NHRA and IHRA SS/LA National Record Holder '00 & '01
Fleet of FoMoCo products
Moneymaker Bio
US Class Nationals link
|
Kyle
Gearhead Posts: 458
From: Sumner, WA
Registered: Dec 2001
|
posted 12-15-2001 02:09 PM
I have a C4 with a B&M transpak in it, so I should be able to put in second without it upshifting. Can I do the "mash it" method like this to check stall?------------------
Kyle Laramore 63 Fairlane
66 Mustang coupe
73 Mach 1
|
Moneymaker
Administrator Posts: 29200
From: Lyons, IL, USA
Registered: May 99
|
posted 12-15-2001 02:23 PM
Yes you can do a 2nd gear test Kyle, if your brakes are good enough to hold the rear tires. You only need to "mash" the pedal for 2 or 3 seconds tops. ------------------
Alex Denysenko
Co-Administrator and Moderator
NHRA/IHRA/SRA member
NHRA and IHRA SS/LA National Record Holder '00 & '01
Fleet of FoMoCo products
Moneymaker Bio
US Class Nationals link
|
steve'66
Gearhead Posts: 9835
From: Sonoma,CA,USA
Registered: Mar 2000
|
posted 12-15-2001 03:51 PM
Wait a minute guys,I'll get the taters, I'm hungry fer some mashed spuds. SteveW
|
Moneymaker
Administrator Posts: 29200
From: Lyons, IL, USA
Registered: May 99
|
posted 12-15-2001 04:39 PM
Don't forget some gravy with that Steve. ------------------
Alex Denysenko
Co-Administrator and Moderator
NHRA/IHRA/SRA member
NHRA and IHRA SS/LA National Record Holder '00 & '01
Fleet of FoMoCo products
Moneymaker Bio
US Class Nationals link
|
Jerry Piner
Gearhead Posts: 257
From: staunton, va
Registered: Dec 2001
|
posted 12-17-2001 02:17 PM
With the set-up I have, with the addition of the 4.56 and an Edelbrock RPM intake, and maybe a carb spacer. Does 6000 rpm sound like a good shift point? OR should i shift higher or lower, when I bought the car the owner had the shift point at at 6700. he also said that he had a 4.56 in the car at one time and said that it ran so much better with it than the 4.11, said it was like night and day.
|
Moneymaker
Administrator Posts: 29200
From: Lyons, IL, USA
Registered: May 99
|
posted 12-17-2001 04:15 PM
6 to 6500 is pretty normal for most street Clevelands. ------------------
Alex Denysenko
Co-Administrator and Moderator
NHRA/IHRA/SRA member
NHRA and IHRA SS/LA National Record Holder '00 & '01
Fleet of FoMoCo products
Moneymaker Bio
US Class Nationals link
|
