Rising Sun Member Forums  

Go Back   Rising Sun Member Forums > Toyota 4x4 > General Tech Forum

Reply
 
Thread Tools
  #21  
Old 12-07-2009, 07:29 AM
RicardoJM's Avatar
RicardoJM RicardoJM is offline
Rising Sun Member
 
Join Date: Jul 2007
Location: Centennial, CO
Posts: 2,305
Default

Quote:
Originally Posted by Jacket View Post
Which rebuild kit did you use? I posted somewhere else that I was surprised at the variability in the parts list included in the different kits. Even the Keyster kits vary quite a bit.
I used a Keyster kit. Yeah, I can understand a "minor rebuild" kit would be just gaskets, but do not understand why there is such variability in the "major rebuild" kits. I was particularly confused at why there was one idle/slow jet in the carb kit and not two.
__________________
Ricardo Maestas - Bio Page
KD0CAW
1999 LX 470
SOLD - 1971 FJ-40
TLCA #18941
Reply With Quote
  #22  
Old 12-07-2009, 07:43 AM
AxleIke's Avatar
AxleIke AxleIke is offline
Rising Sun Member
 
Join Date: Apr 2006
Location: Arvada, CO
Posts: 3,387
Default

GREAT write up Ricardo!
__________________
Isaac

Baby Beast 2- 1999 4Runner SR5

Baby Beast -1987 4Runner SR5-Gone, but not forgotten

Generation Dead
Reply With Quote
  #23  
Old 02-08-2011, 07:59 AM
subzali's Avatar
subzali subzali is offline
Rising Sun member
 
Join Date: Aug 2005
Location: Denver CO
Posts: 7,576
Default

Ricardo,

Have you been tracking your gas mileage since you did the rebuild?

Also, I've been reading that there is a 38/38 and a 38/40. Is the 38/38 the 2 barrel carb for F engines while the 38/40 is the 2 barrel carb for 2F engines? Do you happen to know the venturi size difference between the two? I think on a 38/40 the venturis are 31/35. And from Ed Cook's writeup I think the 38/38 has 28/31 venturis. Do those numbers flange up? I think I'm going to tackle my carb at some point and figure out what I have. I know it's a '78 Federal spec, just don't know how it's jetted and if everything is working properly. How is your secondary actuated? Is it linkage actuated?

Sources:
http://forum.ih8mud.com/60-series-wa...ml#post3043800

http://www.ih8mud.com/tech/carbinfo.php

EDIT: Started a thread about my carb here:
http://risingsun4x4club.org/forum2/s...ad.php?t=15074
__________________
Matt Miller
TLCA# 13684
Rising Sun Bio
1977 FJ40 2F "Brahma" + Lockright, tach, Warn 8274, FJ60 Power Steering, soon to lose the Sanden OBA to go back to factory emissions
1996 FZJ80 1FZ-FE factory lockers + Safari Turbo , CDL switch, cup holder, AATLAS1X leather, heated seats and JDM switches
2000 Tundra Limited TRD 2UZ-FE SOLD

Last edited by subzali; 03-27-2014 at 10:14 AM.
Reply With Quote
  #24  
Old 02-08-2011, 08:45 AM
Jacket's Avatar
Jacket Jacket is offline
Rising Sun Member
 
Join Date: Feb 2007
Location: Lafayette
Posts: 4,078
Default

On the mileage question, I've tracked mine since did the my rebuild in 2009 - no measurable improvement over what it was like before. Many performance improvements, but none in the way of mpg's.
__________________
- Matt
1976 FJ40 - green and mostly stock
1996 FZJ80 - not so stock
Reply With Quote
  #25  
Old 02-08-2011, 08:46 AM
RicardoJM's Avatar
RicardoJM RicardoJM is offline
Rising Sun Member
 
Join Date: Jul 2007
Location: Centennial, CO
Posts: 2,305
Default

Quote:
Originally Posted by subzali View Post
Have you been tracking your gas mileage since you did the rebuild?
Yes, I keep a log book and calculate mileage with each fill up. After the rebuild, I average 12-14 mpg. Up until recently, I was not running vacuum advance. As soon as I started running vacuum advance, I had to deal with the cracked block and just after getting the rebuilt engine in my odometer stopped working. I got it fixed this past weekend.

I'm looking forward to seeing what my mileage is now. Then, I am going to increase my jet size.

Quote:
Originally Posted by subzali View Post
Also, I've been reading that there is a 38/38 and a 38/40. Is the 38/38 the 2 barrel carb for F engines while the 38/40 is the 2 barrel carb for 2F engines? Do you happen to know the venturi size difference between the two? I think on a 38/40 the venturis are 31/35. And from Ed Cook's writeup I think the 38/38 has 28/31 venturis. Do those numbers flange up? I think I'm going to tackle my carb at some point and figure out what I have. I know it's a '78 Federal spec, just don't know how it's jetted and if everything is working properly. How is your secondary actuated? Is it linkage actuated?

Sources:
http://forum.ih8mud.com/60-series-wa...ml#post3043800

http://www.ih8mud.com/tech/carbinfo.php
My research indicates the DD38 was used from 69 through 74. After that, I have not really paid much attention - but it would make sense that the carb specifications (jets, venturi size) would have changed with the "more powerful" 2F.

I'm not sure I understand your question about the "numbers flange up".

My secondary is mechanically actuated. I can tweak the linkage arm to get it to start opening earlier or later. I have not really worked with it to see how adjusting it would affect performance.

I am not a carb guru/expert but have come to understand through experience that the optimum setup (tuned for power or tuned for mileage) is something that will vary for each truck.
__________________
Ricardo Maestas - Bio Page
KD0CAW
1999 LX 470
SOLD - 1971 FJ-40
TLCA #18941
Reply With Quote
  #26  
Old 02-08-2011, 08:58 AM
subzali's Avatar
subzali subzali is offline
Rising Sun member
 
Join Date: Aug 2005
Location: Denver CO
Posts: 7,576
Default

Cool. Thanks for the info. I'm wondering if anybody has an F engine carb, if they could look to see if there are numbers stamped on the venturis, as shown in this thread:
http://forum.ih8mud.com/60-series-wa...-them-out.html

I am expecting to see 28 primary, 31 secondary. If that's true, then those numbers would "flange up" to the research/reading I've done.

EDIT: Matt, what kind of MPG are you getting? What performance improvements did you see?

Ricardo, are you still jetted to these settings? IIRC, you went from a F block to the F1.5 block when you did the latest rebuild right? And you say the F1.5 uses the same 2bbl carb the F block does?
http://risingsun4x4club.org/forum2/s...35&postcount=8

EDIT AGAIN: I think I found my answer about 38/38 being on F engines:
http://forum.ih8mud.com/fj25-owners-...ml#post6235972
__________________
Matt Miller
TLCA# 13684
Rising Sun Bio
1977 FJ40 2F "Brahma" + Lockright, tach, Warn 8274, FJ60 Power Steering, soon to lose the Sanden OBA to go back to factory emissions
1996 FZJ80 1FZ-FE factory lockers + Safari Turbo , CDL switch, cup holder, AATLAS1X leather, heated seats and JDM switches
2000 Tundra Limited TRD 2UZ-FE SOLD

Last edited by subzali; 02-08-2011 at 11:24 AM.
Reply With Quote
  #27  
Old 02-08-2011, 11:23 AM
Jacket's Avatar
Jacket Jacket is offline
Rising Sun Member
 
Join Date: Feb 2007
Location: Lafayette
Posts: 4,078
Default

10-12 mpg for me, but I have heavy steel wheels and 33" MT's (as compared to Ricardo).

I had major issues with climbing at elevation: backfiring, sputtering, and nearly a complete loss of power (there's a thread here somewhere about it) at times. Sometimes I'd be crawling up Eisenhower at 20mph in second gear having to feather the throttle to keep my speed. It would also lose power at high speeds > 45 mph around town; just randomly cut out. And cold idle and cold driving were iffy at best.

Those issues have all disappeared since the rebuild. It still runs rough in the winter if I don't give it a few minutes to warm up, but I think that's "normal." All the hesitation stuff is completely gone.
__________________
- Matt
1976 FJ40 - green and mostly stock
1996 FZJ80 - not so stock
Reply With Quote
  #28  
Old 02-08-2011, 11:50 AM
RicardoJM's Avatar
RicardoJM RicardoJM is offline
Rising Sun Member
 
Join Date: Jul 2007
Location: Centennial, CO
Posts: 2,305
Default

Quote:
Originally Posted by subzali View Post
Cool. Thanks for the info. I'm wondering if anybody has an F engine carb, if they could look to see if there are numbers stamped on the venturis, as shown in this thread:
http://forum.ih8mud.com/60-series-wa...-them-out.html

I am expecting to see 28 primary, 31 secondary. If that's true, then those numbers would "flange up" to the research/reading I've done.

Ricardo, are you still jetted to these settings? IIRC, you went from a F block to the F1.5 block when you did the latest rebuild right? And you say the F1.5 uses the same 2bbl carb the F block does?
http://risingsun4x4club.org/forum2/s...35&postcount=8

EDIT AGAIN: I think I found my answer about 38/38 being on F engines:
http://forum.ih8mud.com/fj25-owners-...ml#post6235972

I'll have to check on the stamping. It may take a few days as I spending my evening giving Sascha a hand with his rig. I do recall seeing numbers stamped into the barrels and they were the same so on that recollection - they don't "flange up".

Yes, I am still running the jet sizes in that post. I did try smaller jets (matching what was in the FSM for altitude) and found that I had a stumble coming of the idle circuit to the primary circuit. Very significant and not good with jet size 112, almost bearable at jet size 114 and gone at 116.

I've actually had 3 engines and 2 rebuilt carbs in my truck over the past year. You need a scorecard to keep track.

My understanding and experience is that the F.5 engine came with the DD38 carb that was also used on the late F engine. Albeit, in 1974 the throttle mechanism was linkage and not cable.

The Blue Mule is running a DD38 on a 2F and many others have success running the combination - I think that Martin has this set up in his rig. Regarding jetting, we put in a slightly larger jet (118 IIRC) in the Blue Mule and noticed a performance improvement. I don't think that Randy tracks MPG so we don't know what the economy impact is. That said, I don't think the Mule will be going back to the smaller jet size.
__________________
Ricardo Maestas - Bio Page
KD0CAW
1999 LX 470
SOLD - 1971 FJ-40
TLCA #18941
Reply With Quote
  #29  
Old 02-08-2011, 01:17 PM
subzali's Avatar
subzali subzali is offline
Rising Sun member
 
Join Date: Aug 2005
Location: Denver CO
Posts: 7,576
Default

Cool, great info Ricardo!

Well I would imagine that someone would have a 38/38 sitting on a bench somewhere and could check it (I think the stamps are visible with the air horn on), but while you're working on Sascha's rig it would be neat if you could take a quick look at his DD38/40 (I'm assuming that's what he has) and see what his venturis are stamped. I'm guessing 31 primary and 35 secondary If we can't get the whole flange to line up then maybe we can at least get a couple bolts started
__________________
Matt Miller
TLCA# 13684
Rising Sun Bio
1977 FJ40 2F "Brahma" + Lockright, tach, Warn 8274, FJ60 Power Steering, soon to lose the Sanden OBA to go back to factory emissions
1996 FZJ80 1FZ-FE factory lockers + Safari Turbo , CDL switch, cup holder, AATLAS1X leather, heated seats and JDM switches
2000 Tundra Limited TRD 2UZ-FE SOLD
Reply With Quote
  #30  
Old 02-08-2011, 04:16 PM
Air Randy's Avatar
Air Randy Air Randy is offline
Cruise Moab Committee
 
Join Date: Aug 2008
Location: Franktown, CO
Posts: 2,804
Default

Quote:
Originally Posted by RicardoJM View Post
The Blue Mule is running a DD38 on a 2F and many others have success running the combination - I think that Martin has this set up in his rig. Regarding jetting, we put in a slightly larger jet (118 IIRC) in the Blue Mule and noticed a performance improvement. I don't think that Randy tracks MPG so we don't know what the economy impact is. That said, I don't think the Mule will be going back to the smaller jet size.
I dont track mpg closely, but when I have done it it worked out to 10-11 mpg. I think the Mule is really heavy with all of the tube work and the 37" tires with steel beadlocks probably add a lot of weight too. And, I know my speedometer is 5 mph slower than actual vehicle speed so that probably factors in.

I had a significant increase in power when I went from the stock jet sizes to the larger ones. It still runs smooth, no black smoke, no plug fouling and the power is much better. It ran good on the snow run too so getting a little higher up didn't seem to make it too rich either.
__________________
Randy Rosetta KDKWX TLCA #19351 69 FJ40 "Meanie" & 1970 Boss 302 Mustang
Reply With Quote
Reply

Thread Tools

Posting Rules
You may not post new threads
You may not post replies
You may not post attachments
You may not edit your posts

BB code is On
Smilies are On
[IMG] code is On
HTML code is Off


All times are GMT -6. The time now is 07:43 AM.


Powered by vBulletin® Version 3.7.1
Copyright ©2000 - 2014, Jelsoft Enterprises Ltd.