#21  
Old 07-11-2019, 05:45 PM
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"...Do I need special springs to run roades lifters?

No. But if you're not familiar with Rhoads lifters, be advised that lots of guys can't stand Rhoads lifters, because of the "ticking" sound they cause, at idle. They bleed off some cam lift & duration at idle & low rpm, then gradually restore full cam lift at aprox 3000-3500 rpm. I love 'em. LOTS of Pontiac guys hate 'em, & badmouth 'em every chance they get. Many are quick to say something like "Rhoads lifters are a crutch. Buy the right cam & you won't need Rhoads lifters".

BUT, Rhoads lifters allow you to run a slightly larger cam, but still have a decent idle, enuff vac to work power brakes, & slightly more torque under 3000rpm. This produces what is called a broader power range, than the same cam would have using regular type lifters. Steep ramp cams, such as the Voodoo series usually don't need Rhoads lifters. They are also not recommended for small cams, which already have a smooth idle & plenty of brake vac.

"...And I guess there needs to b work done to put 1.65 rockers on..."

Yes, need to grind out some for pushrod clearance. Otherwise, some of the pushrods will bind up against the heads, since the 1.65 rockers will position the pushrods closer to the rocker studs.

Last edited by ponyakr; 07-11-2019 at 05:59 PM.
  #22  
Old 07-11-2019, 05:57 PM
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10 mpg is way off the mark for that engine/drivetrain/vehicle combo. With a small cammed 400 and OD transmission I'd expect 15-18 city and 18-20 or so on the highway. The tune just has to be WAY off the mark or a fundamental problem someplace.......Cliff
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73 Ventura, 455, 3740lbs, 11.30's at 120mph, 1977 Pontiac Q-jet, HO intake, HEI, 10" converter, 3.42 gears, DOT's, 7.20's at 96mph and still WAY under the roll bar rule. Best ET to date 7.18 at 97MPH (1/8th mile)
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Old 07-11-2019, 06:33 PM
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Quote:
Originally Posted by Cliff R View Post
10 mpg is way off the mark for that engine/drivetrain/vehicle combo. With a small cammed 400 and OD transmission I'd expect 15-18 city and 18-20 or so on the highway. The tune just has to be WAY off the mark or a fundamental problem someplace.......Cliff
I can't agree more.

I have been all through this engine.
Timing
Initial 15
mechanical 18

All in at about 3000 rpm

It is using manifold vacuum

New HEI, no different on points dist built for engine

735 HR Slayer quikfuel carb

all cylinders are right at 160psi

And the speedometer is correct

Any thoughts would be appreciated.

Greg
  #24  
Old 07-11-2019, 06:42 PM
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Quote:
Originally Posted by footjoy View Post
I can't agree more.

I have been all through this engine.
Timing
Initial 15
mechanical 18

All in at about 3000 rpm

It is using manifold vacuum

New HEI, no different on points dist built for engine

735 HR Slayer quikfuel carb

all cylinders are right at 160psi

And the speedometer is correct

Any thoughts would be appreciated.

Greg
In one of your older threads you said the cam was installed straight up. Being a Crower cam several people say they need to be advanced at least 4 degrees to come in on the correct centerline. Looks like its running retarded timing.
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Old 07-11-2019, 07:13 PM
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Originally Posted by 400 Lemans View Post
In one of your older threads you said the cam was installed straight up. Being a Crower cam several people say they need to be advanced at least 4 degrees to come in on the correct centerline. Looks like its running retarded timing.

The card says it has 4 degrees of advance have been ground into it. Is that what you mean?

Greg
  #26  
Old 07-11-2019, 07:35 PM
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http://forums.maxperformanceinc.com/....php?p=4304819 These guys see this with the Crower cams all the time even though the cam cards claim to have advance already built in.
  #27  
Old 07-11-2019, 08:00 PM
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Well thats a bummer. I don't think I have it in me to pull the front off of that motor.

Cliff is that your guess to?

Greg
  #28  
Old 07-11-2019, 08:29 PM
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Quote:
Originally Posted by footjoy View Post
Well thats a bummer. I don't think I have it in me to pull the front off of that motor.



Cliff is that your guess to?



Greg


This motor runs 180 degrees on a 95 degree day it has snap and will turn the tires, it cruises 75 at 2300 rpm. Runs A/C and doesnt get hot.
How can you tell the cam is installed wrong with out pulling the timing cover off.

I think I am in denial. Thanks



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  #29  
Old 07-11-2019, 10:10 PM
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Quote:
Originally Posted by footjoy View Post
735 HR Slayer quikfuel carb
Are you running the original calibration?

A few hundred dollars in porting could work wonders on a set of heads.
https://headsandmanifolds.wordpress....-head-porting/

Last edited by pastry_chef; 07-11-2019 at 10:22 PM.
  #30  
Old 07-11-2019, 10:17 PM
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[QUOTE=pastry_chef;6040088]Are you running the original calibration?[/QU

I recently changed the squirter because it paused a little pulling away from stop light. But every thing else is factory. I am not a fan but it takes 6-12 months to get a good quadrajet

Today I changed from full manifold vacuum on vacumm advamce to ported.

Thanks

Greg
  #31  
Old 07-11-2019, 10:30 PM
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Quote:
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But every thing else is factory.
Well worth the money.
https://www.summitracing.com/int/par...0300/overview/

Not everyone is comfortable digging into a carb but I think you'd find a few MPG with a few hours tuning. I'd install headers as well.

Last edited by pastry_chef; 07-11-2019 at 10:37 PM.
  #32  
Old 07-12-2019, 03:24 AM
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So I see you have been working on this a lot lately after searching your other threads.
What is unclear is what camshaft you have in it.
In another thread the 60243 Crower was listed, then a 60240? In this thread.
  #33  
Old 07-12-2019, 04:23 AM
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Going from MVA to ported isn't going to effect fuel economy assuming the ported source is correctly located. Using ported vacuum simply means that you aren't adding VA timing at idle and coasting.

I use and prefer ported vacuum for most of my engine builds because they are higher compression with well chosen cams and will not like, want or need a butt-ton of timing at idle. Most are fine with 10-14 degrees initial timing and adding another 10-15 degrees via the VA does NOTHING for them aside from making me close the throttle plates too far at idle and not as steady in and out of gear.

Anyhow, the extra fuel you are consuming has to be going someplace. Assuming the distributor is getting the job done that just leaves the carburetor, and those units are not well known for being super efficient for "normal" driving. I've spent some time with a few Holley and Holley clones, there will be significant improvements waiting for you with custom tuning. You'll need to go into the metering block and air bleeds to clean it up, changing jets and PV's will be a complete waste of time/funds........IMHO........Cliff
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73 Ventura, 455, 3740lbs, 11.30's at 120mph, 1977 Pontiac Q-jet, HO intake, HEI, 10" converter, 3.42 gears, DOT's, 7.20's at 96mph and still WAY under the roll bar rule. Best ET to date 7.18 at 97MPH (1/8th mile)
  #34  
Old 07-12-2019, 06:05 AM
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Quote:
Originally Posted by STEELCITYFIREBIRD View Post
So I see you have been working on this a lot lately after searching your other threads.
What is unclear is what camshaft you have in it.
In another thread the 60243 Crower was listed, then a 60240? In this thread.
Disregard, found clarification.
60240.
  #35  
Old 07-12-2019, 07:31 AM
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The first 400 that was in my Ventura used the Crower 60240. Used the car back then to commute back and forth to work nearly 50 miles each way. Some city, a little steady cruising at 55, quite a bit of stop/start driving. I'd average about 15-17 depending on how many full throttle blasts I did with each tank. At that time the engine had 6X heads on it and backed by a TH400, stock converter and 2.73 gears. It ran 14.0-14.20's at the track right at 99-100mph and best ever 13.78 @ 101 mph in really good air, all runs on BF Goodrich Radial T/A's.

I've used the 60240 exclusively for all the later 400's we've done topped with 5C and 6X heads. I will say that as a replacement cam for those lower compression engines there isn't a better choice out there. I've had GOBS of those engines brought here for customer tuning, a few had the Summit 2800, 280, a couple with the 068, several used the XE262 and even a few folks had RAIV cams in them....yikes!. The XE262 cammed ones were pretty much "turds" far as I'm concerned. Lackluster power and quirky idle quality tops the list of what I found with them. The 2800 actually does pretty good, the 2801 is a slug off the line but comes on decent in the mid-range and finishes pretty good. The 60240 makes right at 12" vacuum at idle, strong power from about 2000 rpms to 5000rpms, with very strong mid-range power (for one of those low compression engines).

As for cam timing, like everything else with this hobby and engine building, it should be checked/degree'd when installed. Most Crower cams I've installed have required at least 2 degrees advance, the vast majority needed 4 degrees to get them where they needed to be........FWIW.......Cliff
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73 Ventura, 455, 3740lbs, 11.30's at 120mph, 1977 Pontiac Q-jet, HO intake, HEI, 10" converter, 3.42 gears, DOT's, 7.20's at 96mph and still WAY under the roll bar rule. Best ET to date 7.18 at 97MPH (1/8th mile)
  #36  
Old 07-12-2019, 09:24 PM
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The mechanical advance is in at 3000 rpm and your cruising rpm is likely lower than that with the o/d trans so you may not be getting full advance.
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Old 07-13-2019, 08:34 AM
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The mechanical advance is in at 3000 rpm and your cruising rpm is likely lower than that with the o/d trans so you may not be getting full advance.
Well I agree at 70mph I am hitting 2350 rpm. That is why I switched to port vacuum. But I am out of ideas on that. What is the solution to that?
  #38  
Old 07-16-2019, 08:51 AM
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The OP had asked if it's worth converting his #15 castings over to 2.11" and 1.77" valve sizes and here are the results from my doing that to my # 15 castings over the week end.

Here's some things to note about the stock set up.

1) the Intake valve seat OD is only 1.876" so there is some air flow left to be found even with the stock valve size by going out to a OD of 1.945".

2) The stock Exh seat OD is 1.620" and this is way small and could be taken out to 1.645" and in doing so you could even add a small 60 degree bottom cut.

3) The issue with doing either mod will be that you will sink each valve by some .020" which will drop off some compression.

Here's the stock Intake flow numbers and in the second column the numbers for the 2.11" valve with a quick 3 angle valve job ( 30/45/60 ) done to get it into the head, and the third column is the air flow gain or loss.

Flow@28" with stock 30 degree seat .

.050". 41.4. 42.6= +1.2
.100". 75.9. 87.5=+11.6
.200". 139. 149 =+10
.300". 173. 174.8=+1.8
.400". 180. 179.5=-.5
.450". 181.3. 181=-.3
.500" 183.8. 185.8=+2

Now here's the stock Exh flow numbers for the 1.66" valve and then for the 1.77" valve with a 60 degree bottom cut added.
The column are the same as above.

.050". 22.4. 26.3=+3.9
.100". 43.8 55.2=+11.4
.200". 89.9. 112.4=+22.5
.300". 120.2. 147.6=+27.4
.400". 149.5. 170=+20.5
.450". 156.4. 176=+19.6
.500". 161.3. 180=+18.6
.550". 166.6. 185=+18.4
.600". 167.2. 189=+21.8


Average flow gain with the 1.77" valve up to .550" lift is 17.8 cfm.

Exh to Intake ratio now with the 2.12" / 1.77" combo up to .550" lift is 88.9% , so this set up in no way needs a duel pattern Cam if your running even half way good Headers!

The added air flow from stepping up to a 2.11" valve should be worth 3 to 4 hp per cylinder.
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  #39  
Old 07-16-2019, 09:13 AM
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Well I agree at 70mph I am hitting 2350 rpm. That is why I switched to port vacuum. But I am out of ideas on that. What is the solution to that?
Map out your mechanical/rpm and vacuum/advance, vacuum rpm/load.
I'd bet You likely need a lighter sprung vacuum can or quicker in mechanical.
With lower compression it should be tolerated well.

Or cut to the chase and have a tuner tune it.
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