Slant *       6       Forum
Home Home Home
The Place to Go for Slant Six Info!
Click here to help support the Slant Six Forum!
It is currently Sat Nov 30, 2024 8:09 pm

Unanswered topics | Active topics


» » Tech Q & A » Engine

All times are UTC-08:00



Post new topic  Reply to topic  Page 1 of 2
  [ 19 posts ]  Go to page 1 2 Next
  Print view Previous topic | Next topic 
Author Message
rawduster
 Post subject: No power
PostPosted: Sun Nov 12, 2006 7:02 pm 
Offline
2 BBL ''SuperSix''

Joined: Fri Apr 29, 2005 3:25 pm
Posts: 12
Location: knoxville
Car Model:
I cant seem to get any power on take off. When I try to take off from a dead stop I just cant get the car to go. Its not stalling just getting going really slow. Now if runs good on top end and has pretty good power but will not throw you back in the seat. I cant even spin the tires over. My setup is bor 30 over, 60 off the head, offenhouser 4bbl maniflold with a eddlebrock 500, I cant find the spec on the cam but I know I can go anymore or I would not be able to use the stock valve springs so I was told still looking for the spec card. Its solid lift by the way. im running a 904touqflight with a 2200 stall. Rear axel gear is stock witch is around I think a 2:73 or somthing but I know thats not whats killing me because when the motor was stock I had more power. I have hooker headers 3 and 3 true duels. So what do you guys think. I am running the stock points because befor I had eletronic in and ran worse don't ask why just did. timing is around 15 and if I try to move it one way or anther it starts backfiring or pinggin. So i'm lost don't know what to do. :( :(
Top
   
Reply with quote  
SlantSixDan
 Post subject:
PostPosted: Sun Nov 12, 2006 7:07 pm 
Offline
Board Sponsor & Contributor

Joined: Thu Oct 31, 2002 5:39 pm
Posts: 24447
Location: North America
Car Model:
Sounds to me like too much carburetor, too much camshaft, too much header, and too high a torque converter stall speed have killed off your low-end torque, and a too-tall rear axle ratio is aggravating the problem. What goals did you have in mind when you put together this engine? If you were after low-end torque to speak of, somebody gave you bad advice as to what parts to use to achieve it.

_________________
一期一会
Too many people who were born on third base actually believe they've hit a triple.

Image
Top
   
Reply with quote  
rawduster
 Post subject:
PostPosted: Sun Nov 12, 2006 7:19 pm 
Offline
2 BBL ''SuperSix''

Joined: Fri Apr 29, 2005 3:25 pm
Posts: 12
Location: knoxville
Car Model:
I had a 390 holly and would run good when at idel. When tacking off same thing slow and if you got on it all the way it would stall, when i put the 500cfm on the stalling stop but I still have the slow take off. I did have the stock converter in but would jerk in gear and give you wiphlash. The new converter does not do that. When I first was going to redo the car I was going to go v8 becasue im use to doing ford and chevys but when I meet Mureil B years ago he talked me into build this slant 6 up. Some of you may know Muriel B he has a slant 6 car called the Half Hemi thats red. So I got the specs from him and has a local shop her in knoxville Tn put it all together because I had never done a slant 6 motor. How can it have to much Header? Ive never heard that one?
Top
   
Reply with quote  
rawduster
 Post subject:
PostPosted: Sun Nov 12, 2006 7:31 pm 
Offline
2 BBL ''SuperSix''

Joined: Fri Apr 29, 2005 3:25 pm
Posts: 12
Location: knoxville
Car Model:
think this is the spec on the cam hope this helps too. P4529342 268*268* duration 460-460 lift..........I was think it said 440-440 lift at one time but still looking for the other paper
Top
   
Reply with quote  
BigBlockBanjo
 Post subject: No power
PostPosted: Sun Nov 12, 2006 7:33 pm 
Offline
EFI Slant 6
User avatar

Joined: Sat Oct 07, 2006 10:29 am
Posts: 344
Location: Tennessee
Car Model:
I think he means that it may have to large a primary tube diameter.
Smaller would help low-end. Big pipes make low-RPM flow lazy.

_________________
225 Cubic Inches of Iron-Head American Muscle

225 bored .040 /.100 off block, Schneider Cam 224@.050~ .480 lift - Stock valves, blended bowls, Offenhauser intake with 500 Edelbrock carb
Top
   
Reply with quote  
rawduster
 Post subject:
PostPosted: Sun Nov 12, 2006 7:42 pm 
Offline
2 BBL ''SuperSix''

Joined: Fri Apr 29, 2005 3:25 pm
Posts: 12
Location: knoxville
Car Model:
got yea, is this only with the slant six. I know on our mustang bigger is better more air out and more air in. Im new at the slant stuff so it ok to fire away at me...lol :D
Top
   
Reply with quote  
LUCKY13
 Post subject:
PostPosted: Sun Nov 12, 2006 7:46 pm 
Offline
Turbo Slant 6

Joined: Thu Jul 13, 2006 8:05 pm
Posts: 770
Car Model:
There is many things that can contribute to this. One thing even though you ran better when stock on the 273 gear it is not what your combo needs now. You need a lower gear , atleast a 355 and a 391 would do even better. Your combo of parts just needs more rear gear.


Other things to looks for are.

What size/type exhaust do you have, not the headers but the rest of the exhaust. It needs to be very good flowing but also not to big on the tubing size. A duel exhaust will probably kill the bottom end also.

Cam indexing, Valve ajustment, Timming curve, Carb jetting can all play a hugh part in the power of a setup like this (You could be loosing 75 horse power just by the tune up along) . By the description of what the engine does when you change the timing tells me there is something not right. And if a electronic dizzy setup ran worse then there is something wrong for sure.

Run a compression test, and a leak down test <---(most important). this can give a hint to some of the problems even if the engine is sealed up good on compression.


The Valve ajustment/rocker arm ajustment would be a very good place to look at first. When timing is unresponsive this is a good indication of problems in this area including the possibility of valves leaking when in the higher RPM range. The valves, timing & exhaust should all be right before attemting to tun the carb also. What work has been done to the head, any port work, bigger valves?

Have you ran the car at the track to know what it runs, this is a good test for the amount of horse power being made. Not the ET its self but the MPH.

IMHO I dont feal you are to big on anything except for possibly the exhaust size but I dont know what size it is yet, and also not enough rear gear.



Jess
Top
   
Reply with quote  
ceej
 Post subject:
PostPosted: Sun Nov 12, 2006 7:59 pm 
Offline
Site Admin
User avatar

Joined: Mon Mar 31, 2003 1:04 pm
Posts: 7416
Location: Oregon
Car Model: 2023 Eichman Digger?
If you have too much volume in the exhaust, you will not scavenge correctly.

You have way too much carburetor. You can't spin a 225 sixty over fast enough to breath that much.

AIn't gonna happen unless your doing something for a sixty second lifespan drag motor. My 390 never pulls fully into the seconday. Thank god it's a vac system. It will be pushing it to do so with my 248 Slant. The engine doesn't flow that much air.

2.76's will suck the life right out of a performance build. Ask me how I know! :D
You are not going to scratch the tires with your present build. Heck. You're going to be lucky to perform as well as the stock build. Wrong combo.

(this area had an Edelbrock slam in it that was inappropriate. I have this rule about not posting after drinking beer. I broke my rule. Please disregard.) :oops:

Schludwiller.

Combined efficiency. You have the right stall, but your butt gears are way too high.

Lot's of better /6 guys on here than me... Speak up!

CJ


Last edited by ceej on Mon Nov 13, 2006 7:24 am, edited 1 time in total.

Top
   
Reply with quote  
BigBlockBanjo
 Post subject: No power
PostPosted: Sun Nov 12, 2006 9:17 pm 
Offline
EFI Slant 6
User avatar

Joined: Sat Oct 07, 2006 10:29 am
Posts: 344
Location: Tennessee
Car Model:
I'm with CJ. A 500 is just too dang big. I heard someone mention a 600 double-pumper. Yeah, and it's a MEAN slant!. Most NA engines use from 1.5 to 2 cfm of air, per cubic inch. Stock or Wild. Average is 1.75 cfm. If you put it on paper....1.75 X 225 = 393.75cfm. Better response anyway.
IMHO, 3:73 gears would wake 'er up to. And I thought Hooker's slant headers were made to help torque?? 40 in. Primarys.....and you can get 'em from Summit. Easy. 8)

_________________
225 Cubic Inches of Iron-Head American Muscle

225 bored .040 /.100 off block, Schneider Cam 224@.050~ .480 lift - Stock valves, blended bowls, Offenhauser intake with 500 Edelbrock carb
Top
   
Reply with quote  
sixpar
 Post subject:
PostPosted: Sun Nov 12, 2006 10:19 pm 
Offline
TBI Slant 6
User avatar

Joined: Sat Mar 06, 2004 8:32 pm
Posts: 114
Location: Eugene, OR
Car Model:
Schludwiller! Haven't heard(or seen) that in 20 years. Thanks CJ you made my day. :D
Top
   
Reply with quote  
ceej
 Post subject:
PostPosted: Sun Nov 12, 2006 10:35 pm 
Offline
Site Admin
User avatar

Joined: Mon Mar 31, 2003 1:04 pm
Posts: 7416
Location: Oregon
Car Model: 2023 Eichman Digger?
Quote:
Schludwiller! Haven't heard(or seen) that in 20 years. Thanks CJ you made my day. :D
Heh! :D

CJ
Top
   
Reply with quote  
LUCKY13
 Post subject:
PostPosted: Sun Nov 12, 2006 10:44 pm 
Offline
Turbo Slant 6

Joined: Thu Jul 13, 2006 8:05 pm
Posts: 770
Car Model:
Quote:
If you have too much volume in the exhaust, you will not scavenge correctly.

You have way too much carburetor. You can't spin a 225 sixty over fast enough to breath that much.

AIn't gonna happen unless your doing something for a sixty second lifespan drag motor. My 390 never pulls fully into the seconday. Thank god it's a vac system. It will be pushing it to do so with my 248 Slant. The engine doesn't flow that much air.

2.76's will suck the life right out of a performance build. Ask me how I know! :D
You are not going to scratch the tires with your present build. Heck. You're going to be lucky to perform as well as the stock build. Wrong combo.

I built an Edelbrock 525 for a 318 a few years back. When I finally decided I couldn't get the mixture right, I took it to a specialty shop that was "The place" for Edelbrocks. They didn't charge me anthing. Said it was perfect. That's the last Edlelbrock I bought. Went back to Holley's. The 318 couldn't breath the 525. Too dang much carb. Edelbrocks are a goofy system to try to get performance out of. Big Carbs don't work on small engines. We got small engines.
You want performance? Don't waste time on Carter/Edelbrock crud, unless you can quantify the amount of weight to affix to the secondary circuit. That varies a tremendous amount if you change the number of passengers in your car. I had to epoxy a penny to the counterweight. That's flippin scientific... Not.

Schludwiller.

There are a lot of variables in your build that need to be taken into account. I'm in the middle of a Chevy 230 build. Way over carbed. Total mess. And it has a 1bbl on it! Numbers have got to make sense. Combined efficiency. You have the right stall, but your butt gears are way too high.
You should be in the 9:1 range for compression, but that depends on where you cc'd out. Did you degree your cam? Did you get base numbers, or just build and go?

Lot's of better /6 guys on here than me... Speak up!

CJ

I will have to kinda dissagree on this. plenty of Slants running 500 & bigger carbs with good results. And I sure cant go kicken on Eddy carb, they work quit nice if you know how to work with them. After all they was taken from a design from a Mopar carb which was made by Carter. They may be a bit diff than a Holley (which work good also) but there is plenty of ajustability in them to get fueling matched up. And if you dare jump into the air bleeds they can even be quit impressive.


Jess
Top
   
Reply with quote  
Charrlie_S
 Post subject:
PostPosted: Mon Nov 13, 2006 4:06 am 
Offline
SL6 Racer & Moderator
User avatar

Joined: Sat Oct 19, 2002 12:06 pm
Posts: 8710
Location: Silver Springs, Fl.
Car Model:
Rawduster:
Have you talked to Meril Brunner, about your problem? I would recommend doing that. You are close enough to him, that he can get "hands on". Did he build the engine or just suggest parts? Hands on is a lot easier to diagnose a problem, then long distance, in the forum.

_________________
Charrlie_S
65 Valiant 100 2dr post 170 turbo
66 Valiant Signet 170 nitrous
64 Valiant Signet
64 Valiant 4dr 170
64 Valiant 4dr 225
Top
   
Reply with quote  
rawduster
 Post subject:
PostPosted: Mon Nov 13, 2006 5:48 am 
Offline
2 BBL ''SuperSix''

Joined: Fri Apr 29, 2005 3:25 pm
Posts: 12
Location: knoxville
Car Model:
thanks for a the good info guys. the rest of the exhauset is 2 1/2 back to the rear off the headers. I got the motor specs from him and had Hensly Racing build it. I may just run the car up to him and see what he think, thats what my dad keeps saying..lol
Top
   
Reply with quote  
DusterIdiot
 Post subject: Lol....
PostPosted: Mon Nov 13, 2006 6:21 am 
Offline
Board Sponsor
User avatar

Joined: Tue Oct 29, 2002 8:27 pm
Posts: 9714
Location: Salem, OR
Car Model:
I'm going to think were pretty close here, the setup isn't going to like that convertor or gearing at all, the build in general has the ability to make some nice power and use the carb adequately, it's pretty close to the slant sickness build, so some 3.73/3.91's and a better convertor are in order, also the timing curve has to match, and be more agressive once the drivetrain has been modified or it will still be sluggy also (nothing like waiting for that stock heavy spring to stretch enough to get the mix to light off properly), you also have to dial the carb in as none are plug and play out of the box.

Once you get those things straightened up, I would suggest checking your exhaust system for backpressure (an exhaust shop can help out), they can help nail down if the muffler is too restrictive, you have free flow, etc...

Let us know what Meril has to say, I'd be curious too...

-D.Idiot
Top
   
Reply with quote  
Display posts from previous:  Sort by  
Post new topic  Reply to topic  Page 1 of 2
  [ 19 posts ]  Go to page 1 2 Next

» » Tech Q & A » Engine

All times are UTC-08:00

Who is online

Users browsing this forum: Semrush [Bot] and 15 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 Limited