...

Go Back   Lateral-g Forums > Technical Discussions > Race Cars and Modern Pro-Street
User Name
Password



Reply
 
Thread Tools Display Modes
  #1  
Old 02-12-2014, 08:46 AM
ccracin's Avatar
ccracin ccracin is offline
Senior Member
 
Join Date: Sep 2006
Location: Rostraver, PA
Posts: 2,074
Thanks: 0
Thanked 2 Times in 2 Posts
Default Asphalt Modified Discussion

I sent Ron Sutton a PM regarding some help I am trying to provide a friend that purchased my old Asphalt Modified some years ago. He thought it would be helpful to start a thread just in case anyone was interested in the discussion. So here we go. We have had quite a bit of instability with asphalt short track racing in southwestern PA for the last 5+ years I would say. Because of that and other reasons this car hasn't run much. With the start of 2014 both 1/2 mile tracks have been purchased by new owners and will be opened with full race schedules. It's not important to the discussion, but here is the car before I sold it. Everyone likes pictures!



The current owners want to come back out and run a full season. In the years that have passed since I ran it the engine rules have changed to a point that the combination he has is not competitive. They are on a budget and can't go to one of the top builders in the area that have good packages. I want to try and point them in the right direction so that when they freshen their engine here in the next few weeks, they can make some changes for the better. As we all know tailoring an engine for it's intended purpose is a complex deal. I am quite sure we will not be able to go all out, but the discussion should be interesting. On to the details:

The rules the track currently uses are as follows. I trimmed them to just what applies to this car.
*Must be NASCAR recognized small block engines.
*Maximum engine displacement of 360 cid.
*Must be stock cast iron blocks with all standard internal and external
dimensions except the allowable maximum overbore.
*Steel crank and rods only.
*Minimum crankshaft weight 48 lbs.
*No modifications to the crankshaft counterweights.
*Crankshaft must be identical in construction and appearance as OEM crankshaft.
*Minimum rod journal size 2.100 minus .030.
*The stroke may not be increased or decreased.
*Pistons must be 3 ring grooves with 3 rings in place flat tops or dished.
*No portion of the piston may protrude above the top of the block.
*Crankshaft must be stock stroke for the engine size being used.
*Compression ratio may not exceed 10.8/1 as computed by the track KATECH whistler. NO TOLERANCE.
*No dry sump oiling permitted.
*Engines must be a minimum of 350 cid.
*No coatings on any internal engine parts including but not limited to ceramic.

*Cast iron stock heads only. No Vortec style or center mounted valve cover mounting stud - style permitted.
*General Motors may use GM #10134392 casting #14011034, GM
#3987376 casting #3991492, GM #12480034.
*General Motors may not use GM #12529093 casting #102339906
*All valves must remain identical to stock OEM for head being used.
*No porting, port matching, polishing, Hog Cutting or cleaning up of the
heads permitted.
*2 valves per cylinder.
*Only steel valves and valve springs permitted.
*Flat tappet cams and lifters ONLY
*No mushroom, roller, or oversized lifter permitted.
*Stud mounted roller rocker arms permitted, maximum 1.65to 1 ratio
*Listed below is the ONLY approved intake manifolds permitted.
*These manifolds must remain as manufactured. No porting, port matching, grinding or polishing permitted.
*Manifolds may not be painted.
*All part numbers are Edelbrock Performer Series intake manifolds:
1.Chevrolet-#2101
*Following is the ONLY approved carburetor:
1. Holley 2300 two-barrel 500 CFM carburetor, model #4412, including
the HP model.
(The rework guidelines dictate the carb should not be modified and pass all Holley gauge inspections.)
*ONLY a Moroso #64966 un-modified carburetor adapter permitted.
*Gaskets used between carb and adapter must be paper .065 inch maximum thickness.
*Maximum of two gaskets, carb to adapter to manifold permitted.
*Fuel must be race gasoline with no oxygen carrying additives. NO METHANOL.

I forgot to add, they also have to run a 6300rpm rev limiter chip

I know that was long and involved Ron, but better to have all the information. Their current combination requires new pistons, but they want to reuse their crank and rods. Crank is a stock 3.48" stroke chevy steel crank. I believe they have 6" I-Beam rods that are not considered light weight. I can ge the specs if needed. The areas that are open for improvement are pistons, heads, and cam. They have the intake and carb. Currently they have 492 heads with 2.02 and 1.6 valves. They worked well when we ran 350cfm carbs with restrictor plates. Now I think they can do better with 034 bow tie heads.

I'll quit now and hopefully you can give me some thoughts. Thanks very much for your time. I'm really excited to get my foot back in this circle a bit.
__________________
Chad
Instagram - @cctek
https://https://www.facebook.com/CCTek

68 Chevy Pickup Project
Build Thread: https://lateral-g.net/forums/showthread.php4?t=7505

THANKS TO: A&M Machine and Fabrication, CCTek (http://www.candctek.com), Hermance Design(www.hermancedesign.com), Paradise Road Rod & Custom, Harry Opfer Welding, Wegner Automotive Research, Clayton Machine Works

Last edited by ccracin; 02-12-2014 at 03:52 PM. Reason: Missing Info
Reply With Quote
  #2  
Old 02-12-2014, 09:44 AM
ironworks's Avatar
ironworks ironworks is offline
Senior Member
 
Join Date: Oct 2005
Location: Bakersfield, Ca
Posts: 5,145
Thanks: 3
Thanked 25 Times in 15 Posts
Default

Also looks like the carb is open for discussion.

There are some great rebuilders out the that will make the 4412 carb a true runner and worth 10hp. I noticed quite a difference in mine.
__________________
www.ironworksspeedandkustom.com
Reply With Quote
  #3  
Old 02-12-2014, 09:52 AM
ccracin's Avatar
ccracin ccracin is offline
Senior Member
 
Join Date: Sep 2006
Location: Rostraver, PA
Posts: 2,074
Thanks: 0
Thanked 2 Times in 2 Posts
Default

Quote:
Originally Posted by ironworks View Post
Also looks like the carb is open for discussion.

There are some great rebuilders out the that will make the 4412 carb a true runner and worth 10hp. I noticed quite a difference in mine.
I agree, we had the same rules for the 350cfm carbs when I ran. I had 2 different "built" carbs and a box stock. Both Built carbs were worth 8+ hp with the restrictor plate, but more important the throttle response was dramatically improved. They may be willing to do something there. I want to give them a list of things that can be done, then it will be up to them as to what they can and want to do.
__________________
Chad
Instagram - @cctek
https://https://www.facebook.com/CCTek

68 Chevy Pickup Project
Build Thread: https://lateral-g.net/forums/showthread.php4?t=7505

THANKS TO: A&M Machine and Fabrication, CCTek (http://www.candctek.com), Hermance Design(www.hermancedesign.com), Paradise Road Rod & Custom, Harry Opfer Welding, Wegner Automotive Research, Clayton Machine Works
Reply With Quote
  #4  
Old 02-12-2014, 02:46 PM
Che70velle's Avatar
Che70velle Che70velle is offline
Senior Member
 
Join Date: Aug 2012
Location: Dawsonville Georgia
Posts: 2,078
Thanks: 180
Thanked 51 Times in 41 Posts
Default

Chad, what combination is together, currently? Tell us what is there, and perhaps that would give us an idea of where they need to go.
I'd be inclined to say that there have probably been more advances in suspension technology, that should be addressed, that would make them quicker, than actual engine upgrades. I ran Lanier National Speedway, across from Road Atlanta, with our asphalt late models. It was a 3/8 mile low banked track, and my engine builder would constantly tell me to put my money in my chassis. He was always right.
__________________
Scott
---------------------------------------------------------------
70 velle' on custom chassis w/custom RideTech coilovers, RED sleeved 434” with Mamo 265’s, built T56, 12 bolt 3:73, wilwood 6/4's, bla, bla, bla...build. thread https://lateral-g.net/forums/showthread.php4?t=39631
New 434” engine build here https://ls1tech.com/forums/generatio...ved-block.html

Thanks Dad!!

My Chevelle is old school... It has a belt driven power steering pump.
They're 17's, but I keep em clean!
Reply With Quote
  #5  
Old 02-12-2014, 03:50 PM
ccracin's Avatar
ccracin ccracin is offline
Senior Member
 
Join Date: Sep 2006
Location: Rostraver, PA
Posts: 2,074
Thanks: 0
Thanked 2 Times in 2 Posts
Default

Quote:
Originally Posted by Che70velle View Post
Chad, what combination is together, currently? Tell us what is there, and perhaps that would give us an idea of where they need to go.
I'd be inclined to say that there have probably been more advances in suspension technology, that should be addressed, that would make them quicker, than actual engine upgrades. I ran Lanier National Speedway, across from Road Atlanta, with our asphalt late models. It was a 3/8 mile low banked track, and my engine builder would constantly tell me to put my money in my chassis. He was always right.
I don't disagree with you at all about the chassis. I agree and can help them in that regard. There have definitely been changes in chassis technology since this car was built. Unfortunately only minor changes will be possible based on the budget from what I am being told. The few races he ran last year, he looked to be close with the chassis. Unfortunately they are changing tires on them again, so it will be back to testing there. He is definitely down on power. I truly believe this will be his best bang for the buck. A chassis guy always wants power and an engine guy says the car doesn't handle well enough. Thats why I like this helping out, I'm impartial! LOL

He is still running the combination of heads and cam I ran with a 350cfm 2 barrel and an 1.125" restrictor plate. There is no way this is adequate for a good 500 2bbl with no plate that I can see. He had all the tell tale sounds of lack of power last year when he ran. He could gain a car length coming out of the corner and lose 1.5-2 from the flagman to turn 1 on a half mile track. That deal was set-up to make torque and be run with a slightly higher gear to run at the end of the straight. Now the guys can put a lower gear in and have the legs to get to the end of the straight and hit the 6300 chip they are mandated to run.
__________________
Chad
Instagram - @cctek
https://https://www.facebook.com/CCTek

68 Chevy Pickup Project
Build Thread: https://lateral-g.net/forums/showthread.php4?t=7505

THANKS TO: A&M Machine and Fabrication, CCTek (http://www.candctek.com), Hermance Design(www.hermancedesign.com), Paradise Road Rod & Custom, Harry Opfer Welding, Wegner Automotive Research, Clayton Machine Works
Reply With Quote
  #6  
Old 02-12-2014, 07:14 PM
Ron Sutton's Avatar
Ron Sutton Ron Sutton is offline
Senior Member
 
Join Date: May 2013
Location: Folsom, CA
Posts: 2,927
Thanks: 45
Thanked 37 Times in 28 Posts
Default

Hi Chad,

The key to optimizing restricted engines is to not leave anything on the table & take nothing for granted.
Every little bit matters. 10.8 compression is better than 10.7 ... 510 cfm is better than 500 cfm … a few ounces here & there … etc, etc.


A. The 034 bowtie head is the best of those options hands down. I think it flows around 215 cfm, which isn’t anything astounding but it’s the best cast iron GM SBC head.

B. A big deal in these engine is the getting the "squish band" to the optimum number of .035". This means "cold" the piston has .035" clearance to the head surface. This is achieved with a combination of head gasket thickness & block decking.

As an example,

If they run a .041" FelPro gasket, the piston needs to stick out of the block by .006" ... putting the top of the piston at .035” from the head.
If they run a .039" FelPro gasket, the piston needs to stick out of the block by .004" ... putting the top of the piston at .035” from the head.
If they run a .031” FelPro gasket, the piston needs to be down in the bore by .004” ... putting the top of the piston at .035” from the head.

While we’re on head gaskets, run the smallest diameter bore you can. If the engine bore is 4.040”, try to get a head gasket bore around 4.080”. To achieve the optimum squish band, you’ll need a gasket .035” or thinner to meet the "no piston above the deck rule". There are several around .031” See if you can get them with the 4.080” bore. That would be a good gasket for this app with the small 64cc chamber.

C. If the track doesn’t tech carbs with a gauge, there is 30 precious cfm with some TLC. If they do, see if they tech the butterfly shafts. Milling them is worth 10cfm. If the carb has to be 100% gauge legal, it still needs to be reworked.

D. K&N Filters designed a racing filter with a profiled top & bottom that flat out flows more air. Since every CFM matters, you’ll want to use the K&N “Flow Control System” on their 2-barrel. Run the 4.5” tall version & pick the correct one if the carb has the choke horn still on or not.

E. Too bad you can’t switch manifolds. The Edelbrock Victor Jr 2-BBl … is the best mid range Intake manifold I have found through testing. In fact, with our 587HP 2-barrel 410” engines, we went away from it to kill some mid-range (and gain upper end.) But it sounds like a performer it is. Do the rules allow you to run the air-gap version?

F. I see they do not allow methanol for fuel. What about E85 or “Ethanol”? If they allow E85/ethanol, that is your best choice by far. If they require it to be a certain percentage of ethanol, the best strategy is to mix Ethanol & racing gas. Ethanol will flat out build more top end power, so in the 4000-6300 rpm range they’re have an advanatge.

G. Back on the carb again, if they allow E85, I’ve got a guy I worked with that together we developed some good pieces.

H. Comp Cams has some new-ish solid lifter lobe profiles that have more area under the curve while still allowing standard .842” solid lifters. The mistake too many racers make on restricted engines is under-camming them. They think well there is less airflow, so I need to make all my power down low. This is not optimum. When these are the rules, the racer that builds the most total power under the usable rpm curve … and specifically the last 1500 rpm of powerband … will have a faster combination.

Two keys to cam selection is car handling & driving. If we have a poor handling set-up car that can’t carry as much mid-corner speed without pushing … or a driver that parks it in the corner … we can’t optimize the engine. We have to band-aid the engine to build more low end torque to get the turd out of the corner. So 3800 rpm matters more. On the other hand, if we have a well set-up car … with good front end geometry that allows higher mid-corner speeds … and the driver knows how to get optimum corner speed out of the set-up … we don’t have to worry about the very bottom of the rpm curve. We can build a rocket that is “good” at 4200 … but doesn’t blow the tires away … and is “mean” from 4700-6300.

I have three cams in mind, depending on how good you think they are with corner speed.

I. Header & exhaust design are critical here. For optimum power throughout the range, we need step headers & a crossover. Before I make any specific recommendations, I need to know what cam strategy we land on … and if there are any sound decibel limits we need to meet at the track(s) they run.

J. Gear ratio. If we build the “mean” engine that builds better power up top … and less power down around the corner exit rpm … we can run a step more gear in the rear. This is faster. A lot of guys think if two engines put out the same power at different RPM’s … then they can just gear the car to the power band & they will be equal. Not true.

K. Ignition timing will be more critical with the 10.8-1 compression. I’d start at 37° with this combo. Don’t mess around with advance curves. Ideally in race engines, you want to have full timing at idle. Just use a retard feature for starting it. For these engines I like the MSD E-Curve billet distributer. You can set it up to retard the timing 24° to start … then it goes to full timing at idle once the engine is running. It runs smoother, doesn’t load up, gets rolling easier, gets around the pits better, and handles low speed caution flags better.

If they can afford $200 to put the car on a chassis dyno, you can get the last 20hp of the engine by fine tuning the jetting & timing. Tune for optimum power from 4700-6300 & give up some in the 4000-4300 range so it doesn’t spin the tires easily. This allows the driver to roll the throttle on quicker and get the acceleration cycle started earlier. This is key both to good lap times, but also setting up passes. You can’t pas someone if you can’t get off the corner well enough to get along side them.

Dyno test the timing … up & down from 37° … and whatever timing builds most power from 4700-6300 will be your number. Make 2° changes at first, then fine tune it with 1° changes. 1° matters, especially in restricted race engines.

L. For oil, I strongly urge them to run a “blend” over full synthetic or full petroleum based oil. The “good” petroleum based oils offer better lubricity, for less wear, longer time between rebuilds & frankly more power over a longer period of time. The synthetic part of the blend offers a higher level of heat protection. Thicker viscosities add more friction. Super thin viscosities offer less protection. I’d like to see them run a 10w40 or 15w40 … depending on the rod & main bearing clearances. If you keep them .0015” - .0018” that would be my choice.

M. Blueprinting the oil pump is strongly suggested … or simply buying it that way. Getting the rotors deburred & the clearances optimized so the pump is “low drag” is the goal here. You don’t need a ton of volume or pressure in a SBC turning 6300 rpm. Buy a quality pump, but don’t get carried away with pressure or volume. Both are HP reducers.

O. There doesn’t seem to be a timing chain rule. At a minimum, go with the tru-roller from Cloyes with the index-able gears. If budget allows, I’ve seen better power & extended engine life with the Comp Cams belt drives.

P. I can’t say enough about making the rotational assembly light. If the crank rule is 48#, for Pete’s sake get down right to it. Target 48.5#.

Q. Several manufacturers offer light pistons. I think JE has them around 375 grams with standard pins.

R. An area not tech’ed is piston pins. This thing won’t build major power, so you can run thinner wall, light pins.

S. A little out of order, but whatever cam I recommend, they’re going to want 1.65 roller rockers.

T. With only 6300 rpm, they don’t need big ol’ pushrods. Here is an opportunity to go small diameter & thin wall chromoly & lighten the valvetrain. (Hardend tips.)

U. Spend the little extra for titanium valve spring retainers. They will pay for themselves plus some with extended life of the valvetrain.

V. Probably not a big issue, but make sure the valve springs are set-up close to coil bind to reduce oscillation & bounce. (Remember, the engine doesn’t make compression until the intake valve stops bouncing & actually seals. )

W. Once we land on a cam, valve spring pressure is critical. Too little & we have power loss along with durability issues.

X. Don’t cut corners on the valve guides or seals. We need it sealed with as close to zero oil contamination in the cylinder as possible. Some people justify the cylinder need lubrication, but the low tension oil rings already take care of that.

Y. If we end up on gasoline, run as cold of a plug as possible, like a 1 on an Autolite scale or a 10 on an NGK scale & dial in the jetting & timing. If we run Ethanol, run 1 step hotter … like a 2 on an Autolite scale or a 9 on an NGK scale. Stay away from the trick of week 2, 3, 4 or 987 prong spark plugs. I buy $3 race plugs so I can read them & throw them away. Buy plugs with the strap cut back or cut it back yourself. Gap them at .035" & index it so the gap opening is pointing straight down to the top of the piston or just slightly towards the intake valve.

Z. Frankly, an ignition amplifier won’t build any more power here unless the jetting is too rich. But make sure they have a top notch coil 7 new wires. Replace the wires every season. Don’t wait for them to “go bad.”

Get me answers to my few questions above & we’ll get working on cam & exhaust.


__________________
Ron Sutton Race Technology
Reply With Quote
  #7  
Old 02-12-2014, 08:57 PM
ccracin's Avatar
ccracin ccracin is offline
Senior Member
 
Join Date: Sep 2006
Location: Rostraver, PA
Posts: 2,074
Thanks: 0
Thanked 2 Times in 2 Posts
Default

Can I just first say, I LOVE THIS STUFF! Ok, here we go:

Quote:
Originally Posted by Ron Sutton View Post
Hi Chad,

The key to optimizing restricted engines is to not leave anything on the table & take nothing for granted.
Every little bit matters. 10.8 compression is better than 10.7 ... 510 cfm is better than 500 cfm … a few ounces here & there … etc, etc.


A. The 034 bowtie head is the best of those options hands down. I think it flows around 215 cfm, which isn’t anything astounding but it’s the best cast iron GM SBC head.

B. A big deal in these engine is the getting the "squish band" to the optimum number of .035". This means "cold" the piston has .035" clearance to the head surface. This is achieved with a combination of head gasket thickness & block decking.

As an example,

If they run a .041" FelPro gasket, the piston needs to stick out of the block by .006" ... putting the top of the piston at .035” from the head.
If they run a .039" FelPro gasket, the piston needs to stick out of the block by .004" ... putting the top of the piston at .035” from the head.
If they run a .031” FelPro gasket, the piston needs to be down in the bore by .004” ... putting the top of the piston at .035” from the head.

While we’re on head gaskets, run the smallest diameter bore you can. If the engine bore is 4.040”, try to get a head gasket bore around 4.080”. To achieve the optimum squish band, you’ll need a gasket .035” or thinner to meet the "no piston above the deck rule". There are several around .031” See if you can get them with the 4.080” bore. That would be a good gasket for this app with the small 64cc chamber. When I was running we had a 10.5:1 rule and I ran zero deck with a .035 steel shim gasket, so I had this in mind

C. If the track doesn’t tech carbs with a gauge, there is 30 precious cfm with some TLC. If they do, see if they tech the butterfly shafts. Milling them is worth 10cfm. If the carb has to be 100% gauge legal, it still needs to be reworked. They have a No-Go for the throttle shaft and plate combo, I will try to get that size and see if there is anything we can gain there.

D. K&N Filters designed a racing filter with a profiled top & bottom that flat out flows more air. Since every CFM matters, you’ll want to use the K&N “Flow Control System” on their 2-barrel. Run the 4.5” tall version & pick the correct one if the carb has the choke horn still on or not.Believe it or not they have outlawed that filter housing. you can run a 3x14 K&N element but that's it. No flow control devices at all. The best we can do is the spun aluminum setup from Speedway with the o-ring seal.

E. Too bad you can’t switch manifolds. The Edelbrock Victor Jr 2-BBl … is the best mid range Intake manifold I have found through testing. In fact, with our 587HP 2-barrel 410” engines, we went away from it to kill some mid-range (and gain upper end.) But it sounds like a performer it is. Do the rules allow you to run the air-gap version? Negative on the air-gap. 2101 only.

F. I see they do not allow methanol for fuel. What about E85 or “Ethanol”? If they allow E85/ethanol, that is your best choice by far. If they require it to be a certain percentage of ethanol, the best strategy is to mix Ethanol & racing gas. Ethanol will flat out build more top end power, so in the 4000-6300 rpm range they’re have an advanatge.No alchohol or E85. Must by fuel at the track. VP 110 They will do a specific gravity test.

G. Back on the carb again, if they allow E85, I’ve got a guy I worked with that together we developed some good pieces. Ugh

H. Comp Cams has some new-ish solid lifter lobe profiles that have more area under the curve while still allowing standard .842” solid lifters. The mistake too many racers make on restricted engines is under-camming them. They think well there is less airflow, so I need to make all my power down low. This is not optimum. When these are the rules, the racer that builds the most total power under the usable rpm curve … and specifically the last 1500 rpm of powerband … will have a faster combination.I ran a custom Comp Cam that used the MA Solid Flat Tappet Lobes for .842 lifters. I gave the cam card to them, but I believe it was the 244/248 at .050 on 115 deg. center line. It ran very well with the combo I had.

Two keys to cam selection is car handling & driving. If we have a poor handling set-up car that can’t carry as much mid-corner speed without pushing … or a driver that parks it in the corner … we can’t optimize the engine. We have to band-aid the engine to build more low end torque to get the turd out of the corner. So 3800 rpm matters more. On the other hand, if we have a well set-up car … with good front end geometry that allows higher mid-corner speeds … and the driver knows how to get optimum corner speed out of the set-up … we don’t have to worry about the very bottom of the rpm curve. We can build a rocket that is “good” at 4200 … but doesn’t blow the tires away … and is “mean” from 4700-6300. I'm not sure where he will be honestly. Once he learned the tires, he ran well through the corner. Once I convinced him to use the brake and throttle together in the corner rather than using the engine to brake in the corner he picked up a lot of time. They now have another new tire, the Hoosier Commanche. In my opinion he has the capability of getting there. I would shoot for "maybe" to "mean" from 4700-6300. Make sense?

I have three cams in mind, depending on how good you think they are with corner speed.

I. Header & exhaust design are critical here. For optimum power throughout the range, we need step headers & a crossover. Before I make any specific recommendations, I need to know what cam strategy we land on … and if there are any sound decibel limits we need to meet at the track(s) they run. Sound Limits are 100db at 100 feet. I know he doesn't run crossovers. I did, but he didn't want to pay for the exhaust system when I sold the car. My system was Howe crossovers, 1 5/8" stepped to 1 3/4" with 3" collectors and a 3' to 3" Y and 3" Dynomax Bullet Muffler It worked very well.

J. Gear ratio. If we build the “mean” engine that builds better power up top … and less power down around the corner exit rpm … we can run a step more gear in the rear. This is faster. A lot of guys think if two engines put out the same power at different RPM’s … then they can just gear the car to the power band & they will be equal. Not true. Agreed. The top cars are running a 4.86 and hitting the chip just as they lift for the corner. Although we will have to see what the tire sizes will be as compared to last year to verify this will remain the same. When he ran last year he was topping out between 6 and 6100

K. Ignition timing will be more critical with the 10.8-1 compression. I’d start at 37° with this combo. Don’t mess around with advance curves. Ideally in race engines, you want to have full timing at idle. Just use a retard feature for starting it. For these engines I like the MSD E-Curve billet distributer. You can set it up to retard the timing 24° to start … then it goes to full timing at idle once the engine is running. It runs smoother, doesn’t load up, gets rolling easier, gets around the pits better, and handles low speed caution flags better. The rules state "No electronic timing controls" not sure if this distributor falls in this category.
__________________
Chad
Instagram - @cctek
https://https://www.facebook.com/CCTek

68 Chevy Pickup Project
Build Thread: https://lateral-g.net/forums/showthread.php4?t=7505

THANKS TO: A&M Machine and Fabrication, CCTek (http://www.candctek.com), Hermance Design(www.hermancedesign.com), Paradise Road Rod & Custom, Harry Opfer Welding, Wegner Automotive Research, Clayton Machine Works
Reply With Quote
  #8  
Old 02-12-2014, 08:58 PM
ccracin's Avatar
ccracin ccracin is offline
Senior Member
 
Join Date: Sep 2006
Location: Rostraver, PA
Posts: 2,074
Thanks: 0
Thanked 2 Times in 2 Posts
Default

Quote:
Originally Posted by Ron Sutton View Post
[B] If they can afford $200 to put the car on a chassis dyno, you can get the last 20hp of the engine by fine tuning the jetting & timing. Tune for optimum power from 4700-6300 & give up some in the 4000-4300 range so it doesn’t spin the tires easily. This allows the driver to roll the throttle on quicker and get the acceleration cycle started earlier. This is key both to good lap times, but also setting up passes. You can’t pas someone if you can’t get off the corner well enough to get along side them.

Dyno test the timing … up & down from 37° … and whatever timing builds most power from 4700-6300 will be your number. Make 2° changes at first, then fine tune it with 1° changes. 1° matters, especially in restricted race engines. I will definitely suggest this to them.

L. For oil, I strongly urge them to run a “blend” over full synthetic or full petroleum based oil. The “good” petroleum based oils offer better lubricity, for less wear, longer time between rebuilds & frankly more power over a longer period of time. The synthetic part of the blend offers a higher level of heat protection. Thicker viscosities add more friction. Super thin viscosities offer less protection. I’d like to see them run a 10w40 or 15w40 … depending on the rod & main bearing clearances. If you keep them .0015” - .0018” that would be my choice. Again, I will pass this along

M. Blueprinting the oil pump is strongly suggested … or simply buying it that way. Getting the rotors deburred & the clearances optimized so the pump is “low drag” is the goal here. You don’t need a ton of volume or pressure in a SBC turning 6300 rpm. Buy a quality pump, but don’t get carried away with pressure or volume. Both are HP reducers. Do you have a prefered source and or part number. They will be buying a new pump anyway, I'm sure.

O. There doesn’t seem to be a timing chain rule. At a minimum, go with the tru-roller from Cloyes with the index-able gears. If budget allows, I’ve seen better power & extended engine life with the Comp Cams belt drives. They are currently running the Cloyes Hex Adjust that was on the engine I sold them.

P. I can’t say enough about making the rotational assembly light. If the crank rule is 48#, for Pete’s sake get down right to it. Target 48.5#. I told them this already. Since they are replacing pistons, I told them this can be done if it hasn't already when they have the rotating assembly balanced

Q. Several manufacturers offer light pistons. I think JE has them around 375 grams with standard pins. Already suggested

R. An area not tech’ed is piston pins. This thing won’t build major power, so you can run thinner wall, light pins.Already suggested

S. A little out of order, but whatever cam I recommend, they’re going to want 1.65 roller rockers. I ran Comp Cams Magnum Rockers, but again in saving money, the went will aluminum rollers, not sure of brand. Do you have a preference?

T. With only 6300 rpm, they don’t need big ol’ pushrods. Here is an opportunity to go small diameter & thin wall chromoly & lighten the valvetrain. (Hardend tips.)That's what they had when they got it from me. I will make sure they replace them. You may be confused with some of this. They spun a couple bearings in the motor they got from me. I think due to a water leak, but has not been confirmed. LOL so they transferred the top end to another short block.

U. Spend the little extra for titanium valve spring retainers. They will pay for themselves plus some with extended life of the valvetrain.

V. Probably not a big issue, but make sure the valve springs are set-up close to coil bind to reduce oscillation & bounce. (Remember, the engine doesn’t make compression until the intake valve stops bouncing & actually seals. )

W. Once we land on a cam, valve spring pressure is critical. Too little & we have power loss along with durability issues.

X. Don’t cut corners on the valve guides or seals. We need it sealed with as close to zero oil contamination in the cylinder as possible. Some people justify the cylinder need lubrication, but the low tension oil rings already take care of that.

Y. If we end up on gasoline, run as cold of a plug as possible, like a 1 on an Autolite scale or a 10 on an NGK scale & dial in the jetting & timing. If we run Ethanol, run 1 step hotter … like a 2 on an Autolite scale or a 9 on an NGK scale. Stay away from the trick of week 2, 3, 4 or 987 prong spark plugs. I buy $3 race plugs so I can read them & throw them away. Buy plugs with the strap cut back or cut it back yourself. Gap them at .035" & index it so the gap opening is pointing straight down to the top of the piston or just slightly towards the intake valve.

Z. Frankly, an ignition amplifier won’t build any more power here unless the jetting is too rich. But make sure they have a top notch coil 7 new wires. Replace the wires every season. Don’t wait for them to “go bad.”

Get me answers to my few questions above & we’ll get working on cam & exhaust.


Hopefully I have given you what you need. I plan on taking the results of this discussion and putting together an outline for this engine. I will then pass it along and hope hope hope they work to it.

Later I would like to discuss this car's front end as well as another friend's I help. This car is a Dirtworks Asphalt car Bart Bates built. The other car I help with is an Ellis. I think you are familiar! But that's another topic!

The post had too many characters so I had to split it. In hind site, i should have just refereed to the letters. Next go around!
__________________
Chad
Instagram - @cctek
https://https://www.facebook.com/CCTek

68 Chevy Pickup Project
Build Thread: https://lateral-g.net/forums/showthread.php4?t=7505

THANKS TO: A&M Machine and Fabrication, CCTek (http://www.candctek.com), Hermance Design(www.hermancedesign.com), Paradise Road Rod & Custom, Harry Opfer Welding, Wegner Automotive Research, Clayton Machine Works
Reply With Quote
  #9  
Old 02-12-2014, 11:32 PM
Ron Sutton's Avatar
Ron Sutton Ron Sutton is offline
Senior Member
 
Join Date: May 2013
Location: Folsom, CA
Posts: 2,927
Thanks: 45
Thanked 37 Times in 28 Posts
Default

Quote:
Originally Posted by ccracin View Post
Hopefully I have given you what you need. I plan on taking the results of this discussion and putting together an outline for this engine. I will then pass it along and hope hope hope they work to it.

Later I would like to discuss this car's front end as well as another friend's I help. This car is a Dirtworks Asphalt car Bart Bates built. The other car I help with is an Ellis. I think you are familiar! But that's another topic!

The post had too many characters so I had to split it. In hind site, i should have just refereed to the letters. Next go around!
Yes you have. I think the middle of the three cam options makes sense. Let me play with some cam & exhaust combos & I'll post a package & simulated dyno graph up this weekend.

__________________
Ron Sutton Race Technology
Reply With Quote
  #10  
Old 02-19-2014, 08:05 AM
ccracin's Avatar
ccracin ccracin is offline
Senior Member
 
Join Date: Sep 2006
Location: Rostraver, PA
Posts: 2,074
Thanks: 0
Thanked 2 Times in 2 Posts
Default

Just checking in Ron. Did you go to speedweeks this year?
__________________
Chad
Instagram - @cctek
https://https://www.facebook.com/CCTek

68 Chevy Pickup Project
Build Thread: https://lateral-g.net/forums/showthread.php4?t=7505

THANKS TO: A&M Machine and Fabrication, CCTek (http://www.candctek.com), Hermance Design(www.hermancedesign.com), Paradise Road Rod & Custom, Harry Opfer Welding, Wegner Automotive Research, Clayton Machine Works
Reply With Quote
Reply

Thread Tools
Display Modes

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

Forum Jump


All times are GMT -5. The time now is 01:57 PM.


Powered by vBulletin® Version 3.8.11
Copyright ©2000 - 2019, vBulletin Solutions Inc.
Copyright Lateral-g.net