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 

trying to get to 5.0
Goto page Previous  1, 2, 3, 4, 5, 6  Next
 
Post new topic   Reply to topic    SMOKEmUP.com Forum Index -> Chevy - Big Block
View previous topic :: View next topic  
Author Message
Paul P
Member


Joined: 15 Aug 2002
Posts: 2403
Location: Townsend, Mass.
81572.74 points


1971 Chevrolet Chevelle

PostPosted: Sat Sep 19, 2015 9:23 am    Post subject: Reply with quote

Gear the wee out of it! Angle mill maybe to help that intake valve issue?
_________________
2001 Focus 2.0 Zetec
stock cams, bolt-ons and tune
15.63@87 MPH 1/4mi

1971 - Chevelle 408 SBC N/A
6.86@102.5 MPH 1/8mi
10.78@122 MPH 1/4mi
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 Sep 19, 2015 3:29 pm    Post subject: Reply with quote

im waiting to find out from the engine builder just how tight it will go.

cant really angle mill it because we would have to match the intake to the heads. we need to leave the intake alone so it will fit the next engine we put in the car.

_________________
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
af2
Member


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


1933 Willys Coupe

PostPosted: Sat Sep 19, 2015 5:40 pm    Post subject: Reply with quote

af2 wrote:
.


Also I would be running a 5.38 gear minimum.

.
Back to top
View user's profile Send private message
Paul P
Member


Joined: 15 Aug 2002
Posts: 2403
Location: Townsend, Mass.
81572.74 points


1971 Chevrolet Chevelle

PostPosted: Sun Sep 20, 2015 9:28 am    Post subject: Reply with quote

5.38 gear would increase rpm in the lights to 8250... Too much don't ya think? Unless my math is flawed..
(5.38/4.56)x7000=8258

_________________
2001 Focus 2.0 Zetec
stock cams, bolt-ons and tune
15.63@87 MPH 1/4mi

1971 - Chevelle 408 SBC N/A
6.86@102.5 MPH 1/8mi
10.78@122 MPH 1/4mi
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: Sun Sep 20, 2015 1:38 pm    Post subject: Reply with quote

Adam mentioned the A and B gas cars spinning to 8500 so, i think that's right where hes suggesting the rpm be. i still don't know if we can spin it that high. i would like to get it to 7800. i should know tomorrow.

btw, where did you get that formula?

_________________
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
Paul P
Member


Joined: 15 Aug 2002
Posts: 2403
Location: Townsend, Mass.
81572.74 points


1971 Chevrolet Chevelle

PostPosted: Mon Sep 21, 2015 10:36 am    Post subject: Reply with quote

Yeah I didn't think you were spinning it that high... Laughing

Simple comparison fraction New Gear/Old Gear x your rpm in the traps.

Primitive but a close estimate method. I does assume that the trap speed remains the same. In theory it might leave harder and be trapping higher which would make things a bit worse (higher rpm at the end)

Paul

_________________
2001 Focus 2.0 Zetec
stock cams, bolt-ons and tune
15.63@87 MPH 1/4mi

1971 - Chevelle 408 SBC N/A
6.86@102.5 MPH 1/8mi
10.78@122 MPH 1/4mi
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: Mon Sep 21, 2015 11:49 am    Post subject: Reply with quote

I woke up this AM and thought hey the cam with 113 ls makes sense with the low static compression and running methanol.
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: Mon Sep 21, 2015 11:50 pm    Post subject: Reply with quote

I think we are still talking 1/8 mile? Correct?

Paul's # was at 1/4 mile according to my #'s??
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: Mon Nov 02, 2015 3:29 pm    Post subject: Reply with quote

an update on this....

we pulled the heads and had them ported. they gained 35cfm @ .800 lift. that's right where the cam is. cam was changed to 117lsa.
milled .040 and used a .040 gasket to try to get the compression up a bit. probably only gained about a point.
slight gear change to about a 4:80
6600 converter over the 6000 that we had.

the first time out we had some weird gremlins and didn't make any clean passes. no real problems were found. reset the lash and a new set of plugs with a tighter plug gap and its happy now.

finally made some decent passes in Denton this weekend. its still a 5:30 car. only difference is, it likes more timing, more fuel and will carry the front wheels halfway to the 60.

converter still doesn't flash above 5900. about the same as the old one.
gear change does have the finish line rpm within 100rpm of the shift rpm.

we're going to build another motor. just don't see getting this one where we need to be.

in all honesty, i think what we did actually hurt power. it still didn't run its best time at that track.

_________________
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
af2
Member


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


1933 Willys Coupe

PostPosted: Tue Nov 03, 2015 12:22 am    Post subject: Reply with quote

10sec.et wrote:
an update on this....

cam was changed to 117ls

in all honesty, i think what we did actually hurt power. it still didn't run its best time at that track.


Seriously!!!! Keith not wanting to be a now it all BUT! That 117 ls is what we run on our 6-71 at 15 over and 433"hemi at 9500 rpm. The reason for the wide LS is the fact the shit goes right out the exhaust.

NA needs to be 110 or less to scavenge what is going in.

I do not want to be a know it all but I do know this.. Mabey?
Very Happy Very Happy Very Happy
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: Tue Nov 03, 2015 1:37 am    Post subject: Reply with quote

i agree. im not an engine builder but i thought the guy that specd that went the wrong way. ive heard that from others too.
_________________
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
William Jones
Member


Joined: 30 Jan 2006
Posts: 822
Location: Lake city, FL
28514.86 points


1971 Ford Mustang

PostPosted: Thu Dec 10, 2015 9:50 am    Post subject: Reply with quote

It's a very common practice to run a wide lsa on large CI NA engines. But 117 seems to be a bit much. 111 to 114 is more common. I had Roush spec a NA cam for the Falcons 363ci and they came back with a 110 lsa conventional thinking would say 106 to 108. My custom cam for my 454ci motor was 112. But on another note when you make changes and you get the same results even when weather changes you have bottle neck problem. Like intake to small, heads, exhaust or valve train issues.

Bam

_________________
Take the horse out off the barn and let her RUN BABY RUN!!!!!

92 LX 454ci Clevor 9.24@142.53 N/A
71 Mach1 454ci Clevor 10.16@134 N/A 3850lbs race weight "Lost in fire"
03 Cobra Bone stock 12.42
68 Falcon 363ci 10.55@126 N/A
95 GT 363ci 11.08@118 N/A
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: Sun Dec 13, 2015 10:15 pm    Post subject: Reply with quote

well, the truth is, after the heads were ported and the cam changed, it slowed down. it ran 5.60 with the old tune on the new combination. granted, i didn't expect the old tune to be dead on but i hoped it would be somewhere close. i ran out of pills trying to get back to 5.30. it was really lean down low and really fat up top. i also had to add a lot more timing and it still could take more. unfortunately, i have to modify the bracket for the crank trigger to go any further. i do know the intake isn't too small. its too big , if anything. headers are 2 1/4 primaries into 4" merged collectors with a 10" cone up to 5" then back down to a 4" exit. i suppose the collectors could be a tad small. were only spinning 7800 so i don't see needing bigger primaries. of course, ive been wrong before. the plan, at this point, is to dyno the engine as is and see where we're at. then, put the old cam back in and see what happens. i have the flow specs on the heads somewhere. as i recall, they picked up 35cfm@ 8000rpm.
_________________
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
10sec.et
Member


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


1969 Oldsmobile Cutlass

PostPosted: Fri Jul 15, 2016 7:42 pm    Post subject: Reply with quote

looks like we got all we're going to get out of the old motor. time for something with a little more punch....










_________________
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
af2
Member


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


1933 Willys Coupe

PostPosted: Sat Jul 16, 2016 10:37 pm    Post subject: Reply with quote

Oh Lord,,, that should do it... Cool Cool
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 - Big Block All times are GMT - 5 Hours
Goto page Previous  1, 2, 3, 4, 5, 6  Next
Page 2 of 6

 
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