Home | Register | Login | Contact Us

 
Auto Math
Classifieds
Forum
Gallery
Games
Garage
Tech Articles
Utilites
 
FAQFAQ    SearchSearch    RegisterRegister    Log inLog in    Log in to check your private messagesLog in to check your private messages    Forum Subscriptions1/4 Mile Table 

Torque Monster... Well, not quite
Goto page 1, 2  Next
 
Post new topic   Reply to topic    SMOKEmUP.com Forum Index -> Chevy - Small Block Gen 1
View previous topic :: View next topic  
Author Message
Cheyenne91
Newbie


Joined: 14 Jan 2011
Posts: 6
Location: Penn.
366.44 points



PostPosted: Fri Jan 14, 2011 11:20 pm    Post subject: Torque Monster... Well, not quite Reply with quote

I stumbled onto this forum tonight researching how I'd like to build the engine for my truck. The members seem knowlegeable and hopefully may be able to lend some advice. I've had plenty of experience rebuilding and tweaking Briggs and Kohler engines, but this is my first go at SBC.

I have a 1991 K1500. It's powered by a TBI 4.3 good for putting back and forth, towing... very slowly, and used to be good for 20mpg. She's been a good engine, and exactly what I was looking for four years ago... But times and tastes change... that and my tolerance for oil leaks. I'd like to upgrade, keep mpg in the high(er) teens and trade the rest for low end power and acceleration. It's not going to be a race truck. I tow a 14ft landscaping trailer carrying lawn equipment, aircooled VW's, or the occasional Falcon. My basic concerns are low end torque, fuel economy for when I'm not towing, and due to the ever-fluctuating cost of gas, using 87 octane. TBI and EGR are staying, and WINALDL will be a necessity after the rebuild.

At the moment it uses an open rear with 3.42's. Eventually it's getting upgraded to 3.73's w/ posi, and whatever front axle ratio matches. The 700R4 was rebuilt 10k ago with upgraded internals, external cooler, as well as a hardened sunshell and vette servo.

Either engine will use, most likely, hydraulic flat tappets and roller rockers either 1.5 or 1.6 (possibly staggered rockers), no more than 9.5:1 compression, hi-vol oil pump, long tube headers, UD pulleys, modded TBI, TBI spacer, 3 wire o2 upgrade, and one into two duals with hollowed cat.

It seems like a 350 with dished pistons and 416 heads from a 305 and a towing cam would answer my need for a low torque monster. I can't find any info on use in a daily driver... just track cars and hole-shot machines are what I'm coming across. I'm aware it'll fall on it's face in high rpm's due to valve size and runners. And since I've yet to see a 350 in a 4wd that gets better than 14mpg highway I am assuming mileage wouldn't be very good... But since this engine functions best in low-mid rpms I may be wrong.

I'm probably going to get alot of crap for even mentioning a 305, but with L30, or machined L31 vortec heads and a towing cam seems to be a good setup, although more investment is required for heads, manifold, and machining; Mileage would be much better, and probably more fun to live with, generally speaking. Cylinder shrouding is a concern with L31's on a 305; But I don't think that's much of a problem in low-mid rpms.
Back to top
View user's profile Send private message
Cheyenne91
Newbie


Joined: 14 Jan 2011
Posts: 6
Location: Penn.
366.44 points



PostPosted: Fri Jan 14, 2011 11:49 pm    Post subject: Reply with quote

There's also the possibility of machining 416 heads to bump compression on a 305, or some other head combo...
Back to top
View user's profile Send private message
10sec.et
Member


Joined: 29 Mar 2006
Posts: 3473
Location: Houston,Texas
346658.74 points


1969 Oldsmobile Cutlass

PostPosted: Sat Jan 15, 2011 1:40 am    Post subject: Reply with quote

IMO, 305s are useless for anything but grandmas grocery getter. i learned that the hard way. i figured with less cubic inches in a lightweight truck (S-10) it would get good mileage. in reality, by the time you build enough power in the 305 to get things moving, you end up killing mileage for performance. if youre going to turbo it then maybe but i would seek out a 350. i really dont see getting any better mileage from a low torque 305 in a 4x4. could be wrong though. welcome to SMOKEmUP Cheers
_________________
af2 wrote:
It seems we can look at our magical Balls and come up with a fix?

Back to top
View user's profile Send private message
Cheyenne91
Newbie


Joined: 14 Jan 2011
Posts: 6
Location: Penn.
366.44 points



PostPosted: Sat Jan 15, 2011 10:42 am    Post subject: Reply with quote

How was your 305 Dime set up, 10sec? Not to be skeptical of what you're saying but there are decent powered 305's running economy the high teens. Axle ratio and a heavy foot will destroy mpg of the best intended mileage motor.

What have you built for 350's that have yielded good low-mid and mileage?
Back to top
View user's profile Send private message
jeep_406
Member


Joined: 12 Sep 2002
Posts: 1661
Location: Tewksbury, Mass 01876
53123.48 points


1972 Chevrolet Nova

PostPosted: Sat Jan 15, 2011 5:35 pm    Post subject: Reply with quote

Welcome to SMOKEmUP.com.
What kind of weight are you dealing with? I would think a 383 with a stump puller cam would probably suit your needs. The longer stroke would give you more grunt and probably not cost a lot of gas mileage because it would move your vehicle easier.
Back to top
View user's profile Send private message Send e-mail
robins44
Member


Joined: 29 Dec 2007
Posts: 632

18797.16 points



PostPosted: Sat Jan 15, 2011 7:16 pm    Post subject: Reply with quote

my 1990 k1500 4x4 regular cab short box weighed in at i wanna say 4500 or 4250 with me in it. Its been awhile. I was gonna give ya some pointers but what i have is nothing that you want lol, got a carbed 383 in it now with a th350 tranny, 3.73's with a detroit in the ten bolt rear, and some spray.
Back to top
View user's profile Send private message
Cheyenne91
Newbie


Joined: 14 Jan 2011
Posts: 6
Location: Penn.
366.44 points



PostPosted: Sat Jan 15, 2011 7:33 pm    Post subject: Reply with quote

I have a 14ft landscaping trailer... weighs less than 1000lbs - I don't know the exact weight. I'll haul lawn equipment-maybe a ton, or an old Beetle - 1400-2000 depending on year. Relatively, it's not a massive amount to tow. But it dogs the h3ll out of an anemic 4.3 V6. A 383 may be overkill.

In the beginning, I was seriously considering a 283 or 327 since they're just about square bore-stroke engines. 327 is pretty close to 5.3, and they perform well with good economy(Vortec injection and bore/stroke difference aside). One of the reasons I'm leaning toward the 305 is an 86-94 engine will come with fuel injection provisions. I can therefore spend money on improving what I have instead of collecting requisite parts. Plus with a 3.74" bore and 3.48" stroke being near square, it should have a stout, wide power band with bumped compression, better valve hardware, cam/heads AND have the benefit of smaller displacement for fuel economy.

I MAY be able to get the same benefits from a 350 with 416 heads since it's being limited to low-mid rpms... But I have no real-world, daily driver data to back that theory up.
Back to top
View user's profile Send private message
Cheyenne91
Newbie


Joined: 14 Jan 2011
Posts: 6
Location: Penn.
366.44 points



PostPosted: Sat Jan 15, 2011 7:36 pm    Post subject: Reply with quote

robins44 wrote:
my 1990 k1500 4x4 regular cab short box weighed in at i wanna say 4500 or 4250 with me in it. Its been awhile. I was gonna give ya some pointers but what i have is nothing that you want lol, got a carbed 383 in it now with a th350 tranny, 3.73's with a detroit in the ten bolt rear, and some spray.


That sounds like a fun truck. Nitrous would definitely help climbing the mountain roads around here... Maybe down the road and with a heavily beefed-up 700R
Back to top
View user's profile Send private message
Big Dave
Moderator


Joined: 04 Dec 2005
Posts: 2646
Location: Tampa Florida
119973.02 points



PostPosted: Sun Jan 16, 2011 2:27 pm    Post subject: Reply with quote

I used to tow a 4800 pound pop up camper before I bought my motor home with a 1987 K-20 Suburban. It left the factory with a 650 and I got about 14 mpg with that motor over the first 127,000 miles. After the rear thrust bearing failed I pulled it and installed a 454 (I upgraded the to a 454 TBI throttle body and changed the distributor over to the BBC HEI EFI version). My mileage improved to 16 mph and I was able to pass cars climbing hills in the Rockies while towing the trailer (they all passed me on the down slope side as I like the idea of having brakes at the bottom of a hill).

I thought that if a 454 was better more would really improve my milage so I installed the old ZZ502 out of my Impala into the Suburban but gas mileage suffered as well as tire wear.

Big Dave
Back to top
View user's profile Send private message
clay
Moderator


Joined: 24 Nov 2002
Posts: 3209
Location: South Carolina
318129.23 points


1972 Chevrolet Nova

PostPosted: Sun Jan 16, 2011 10:22 pm    Post subject: Reply with quote

If you're going to run the Vortec heads, why not run the Vortec engine. They are plentiful enough to not be really expensive I would think, have cubic inches, and hydraulic roller cam for better economy. With a halfway decent induction system and a basic header and exhaust setup, it will be light years ahead of your current 4.3 (I have one in an 89 S-10 I've done a few tweaks to). Use the stock cam in the Vortec 350 as it's difficult to upgrade due to valve lift limitations and it will work well for towing. I built one for my cousin about 3 years ago - impressive engine to be all stock. He wants to swap cams now and I think I can use +0.050" locks and get enough to be able to clear the valve seal. I'll start a post on this in a week or two. Welcome to Smokemup. Clay
_________________
I have done so much with so little for so long, I can now do anything with nothing.
Back to top
View user's profile Send private message
cadracer
Newbie


Joined: 28 Nov 2009
Posts: 2

149.96 points



PostPosted: Tue Jan 18, 2011 2:48 am    Post subject: 305 WITH PT72 ON IT Reply with quote

Cheyenne91 wrote:
There's also the possibility of machining 416 heads to bump compression on a 305, or some other head combo...


This engine started out with a lil T3 turbo till it gave up the ghost at 10psi so i installed a t04 and it could only do 14 psi. Mad I built the engine for 20 psi or bust after a year of beating on it i finally got a bigger turbo on it and last time out at the track she took 21psi and was looking for more. Gonna see if she like 25psi.
This is a vortec mild roller hyd cam street driven to the track bolt on 33 1.50 -15 mickey et drag slicks. Pulled a 7.2 through the 1/8 falling off on the top end. Fuel pressure low needs more fuel to the carb.
The t-350 with a 3600 stall couldnt handle it. Blew second gear in the semi finals but still finished 3rd. I coasted and beat him with a 7.4 et he ran a 7.2 all in the reaction time cut a .510 light. I love it they all trailer there's to the track and i drive mine 30 miles to go racing with the slicks and a jack in the back of the truck. Laughing
My wide band start running lean at 16 psi but the Holley 650 is a trooper no blown seals as of yet.Ill keep you posted dyno it in march.
Back to top
View user's profile Send private message Yahoo Messenger
10sec.et
Member


Joined: 29 Mar 2006
Posts: 3473
Location: Houston,Texas
346658.74 points


1969 Oldsmobile Cutlass

PostPosted: Wed Jan 19, 2011 3:03 am    Post subject: Reply with quote

Cheyenne91 wrote:
How was your 305 Dime set up, 10sec? Not to be skeptical of what you're saying but there are decent powered 305's running economy the high teens. Axle ratio and a heavy foot will destroy mpg of the best intended mileage motor.

What have you built for 350's that have yielded good low-mid and mileage?


its been nearly 20 years ago so i dont remember a whole lot of specifics but it didnt have anything radical. had the two barrel Holley Pro-Jection. it averaged about 15 mpg. i think i could have had more power with the same mileage with a 350. as far as 350 builds, im not a "builder". i have worked on/modified a lot but never sat down and blueprinted any Chevys. i honestly couldnt give you a bulletproof recipe for a Chevy. now, if you want to build a BBO...........



"Axle ratio and a heavy foot will destroy mpg of the best intended mileage motor."

guilty Embarassed

_________________
af2 wrote:
It seems we can look at our magical Balls and come up with a fix?

Back to top
View user's profile Send private message
Cheyenne91
Newbie


Joined: 14 Jan 2011
Posts: 6
Location: Penn.
366.44 points



PostPosted: Fri Jan 21, 2011 9:33 pm    Post subject: Reply with quote

Ironically, a guy at work wants to unload a rebuilt 454 he's been sitting on for the past few years. Kept meaning to drop it into his Chevelle but never got to it. I considered dropping it into my half ton, but decided against after realizing what would be needed... not to mention 700r's aren't meant to handle the torque of a BBC.

I'm leaning towards a 305 with milled 416 heads. Keep the coast down, compression up, and should provide good low and mid range towing power. With an RV cam it should pull better than a stock TBI 350 and get better mileage.

Any other ideas I'm all ears.
Back to top
View user's profile Send private message
af2
Member


Joined: 01 Sep 2003
Posts: 5558
Location: grassvalley, ca
71227.76 points


1933 Willys Coupe

PostPosted: Sat Jan 22, 2011 12:53 am    Post subject: Reply with quote

Cheyenne91 wrote:
.. not to mention 700r's aren't meant to handle the torque of a BBC..

Any other ideas I'm all ears.


You might want to reconsider that statement.

You will not have the torque with the BBC to damage the 700.
You will be happy with drive-ability though. Cool
Back to top
View user's profile Send private message
robins44
Member


Joined: 29 Dec 2007
Posts: 632

18797.16 points



PostPosted: Sat Jan 22, 2011 1:04 am    Post subject: Reply with quote

af2 wrote:
Cheyenne91 wrote:
.. not to mention 700r's aren't meant to handle the torque of a BBC..

Any other ideas I'm all ears.


You might want to reconsider that statement.

You will not have the torque with the BBC to damage the 700.
You will be happy with drive-ability though. Cool


At the time back in highschool i wasnt building my own trannys and went threw two "heavy duty" 700r's before going with a th350. Recently i built my th350 bulletproof myself with a aweome kit from dana at probuilt. After talking with dana it sounds like for just a few more dollars you can have a 700r that will handle a fair amount of abuse with some trick parts. Im very happy with my th350 after i got done building it, i did pretty much everything you can do to it minus a transbrake, and the shifting is so fast and positive its rediculous. But im always curious to see what i coulda done with my 700r that originally came in my truck and went out at 350,000 miles. Now im contemplating on getting a gear vendors overdrive when i get the coin.
Back to top
View user's profile Send private message
Display posts from previous:   
Post new topic   Reply to topic    SMOKEmUP.com Forum Index -> Chevy - Small Block Gen 1 All times are GMT - 5 Hours
Goto page 1, 2  Next
Page 1 of 2

 
Jump to:  
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 vote in polls in this forum
You cannot attach files in this forum
You can download files in this forum
Home | Contact Us | Automath | Cam Files | Dyno Search | Forum | Garage | Picture Gallery | Reaction Timer

Copyright 1997-2016 SMOKEmUP.com All rights reserved.
Advertising Info     Disclaimer     Privacy Policy