Welcome to…………..

 

The Rat Patrol’s Mopar Skunkwerks is  dedicated to the retro conversion of  The Rat Patrol – my 1971 Valiant Charger – to a Generation 3  Hemi 6.1 litre engine.

This will include the retro-mod from EFI to carb induction.

image

It will detail all the steps and modifications  necessary to achieve the conversion..including a comprehensive “to do” list and parts list to assist those who may want to try the same ……..

image

1st iteration – single carb on Modman intake – woeful tuning issues with intake

 

image

2nd iteration – dual quads and plenum divider on Modman – improved peak HP but still terrible bottom end signal

 

473471E2-55C5-40A1-853A-75A400C776E6_zpsqlkasczt

3rd iteration – Edelbrock dual plane dual quad – far superior signal strength – Improved peak HP by 20 rwhp – Improved TQ across range by significant amount – Did show some shortage of plenum volume at track, slightly taller than the Modman requires some skimming for engine bay clearance.

 

 

 

 

Advertisements

Building a better Rat Trap

IMG_3162

Forged pistons – with valve reliefs!!

A few weeks ago I made the decision to turn the page on a new chapter.

At the time I first did my conversion, I was in the dark in relation to a few matters which have since come back and haunted me. So I decided to get the motor blueprinted to rectify what were becoming serious issues.

To be clear, the two problems were related in the effect they created, but separate as far as components.

PROBLEM 1 – Piston/Valve clearance.

Factory P/V clearance is tight with factory slugs. Not an issue if you keep the factory cam and factory EFI.

BUT…

– Most aftermarket camshafts for Gen 3 motors are ground with a fairly late Intake Centre Line. This is to ensure the Piston does not hit the Valve.

Not a problem when running EFI, (EFI atomisation is superior) – BIG PROBLEM with carb induction.

A problem called ‘intake reversion’ (The intake charge getting sucked back up the intake) can create fuel pooling in the runners.

RESULT – Bores ‘washed’, Excessive oil burning, bore glazing and bearing damage

SOLUTION – If you want to stick with carbs, get rid of the factory pistons and degree your camshaft correctly.

IMG_3160

Scoured bearings due to oil overheating and thinning.

PROBLEM 2 – Intake options.

At the time I did my install there were very few intake options, mostly inferior to the factory EFI system.

Most are STILL inferior to the factory intake, whether you use an EFI Throttle body or a Carb.

The OCP dual plane intake released two years ago is by far the best designed off-the-shelf carb intake and has been painstakingly dyno tested to prove its efficiency.

The Edelbrock Dual Quad is an old design, and although works acceptably, my testing showed the plenums were arguably still too small.

Anything else, including the ‘drag pack’ style hi rise intakes, have notable deficiencies in their operation.

RESULT – Poor fuel induction with poor low end response, poor fuel mixtures, you can guess the rest!

SOLUTION – If you don’t want to use the factory intake, use the OCP intake.

 

IMG_3161

Glazed bore as a result of intake reversion diluting oil

EXPECTED OUTCOME?

– Well, for a start, no oil burning!

– The cam was retarded 8 degrees, so I expect a significant improvement in induction signal down low and an increase in mid range torque, as well as a more useable power band. I also have the option of going with a bigger cam later.

– The intake and heads are being port matched

– Better grade fasteners are being used and the timing chain is being replaced with a 9 key way double roller.

Stay tuned for progress updates on the rebuild!

In Control!

Retro fitting a Hemi asks for a lot of questions to be answered before deciding how you will control your fuel and spark and before collecting  the stash of parts you need….

The PCM, ECU, ECM or module you choose will be determined by some basic choices:

  • Auto or Stick? And if you’re going with two pedals and not three, what transmission will you use, factory, early Chrysler or some other?
  • Carbs or EFI?
  • Factory EFI or aftermarket system?

The following gives  you an idea of whats out there and when to use it.

NOTE 1 – ‘Smart’ EFI refers to those aftermarket throttle bodies that ‘self learn’ the required fuel/spark parameters

NOTE 2 – The factory PCM will still require re-programming in most retro applications due to certain sensors not being present.

NOTE 3 – The MSD6013 ECU only suits early 5.7 and 6.1 applications as the 5.7 Eagle and 6.4 Apache use a different tone ring for the crank sensor.  

IMG_2095

Dual Edelbrock 500s and Edelbrock dial plane dual quad intake. The ignition controller is the MSD 6013 which suits early 5.7 and 6.1 applications.

———————————————————

1- Combo – G3 hemi, Carb, 727/Stick

FUEL – Carbs
IGN – Factory PCM, MSD 6013, Holley HP/ECU, FAST XIM

2- Combo- G3 hemi, Factory EFI, 727/Stick

FUEL – FAST XFI
IGN – FAST XIM , MSD6013
FUEL/IGNITION – Fact PCM, Megasquirt, Microsquirt, Fueltech, Holley Dominator/ECU, (Autronic, Motec, Wolf – all require ignitor box)

3- Combo- G3 hemi, ‘Smart’ EFI TB, 727

FUEL /IGNITION – MSD ATOMIC, Holley HP 4BBL, FiTech, 

**Will require use of carb intake

4- Combo – G3 hemi, Factory EFI, Factory transmission

ALL – Factory PCM
FUEL/IGN – All used with Sound German Auto trans controller – Megasquirt, Microsquirt, FAST XFI/ XIM , Holley Dominator/ECU , Fueltech, (Motec, Autronic, Wolf – all require ignitors)
TRANS – Sound German Automotive

5- Combo – G3 hemi, ‘Smart’ EFI TB, Factory transmission

FUEL/IGN – MSD Atomic, Holley HP 4BBL, FiTech
TRANS – Factory PCM, Sound German Automotive Trans Controller , – Must be used when running Holley, MSD, Fitech

OCP intake

This OCP brand dual plane single plenum intake is arguably the best most versatile Gen 3 intake on the market. Designed by Joe O’Cone..it reproduces similar hp/tq figures to the factory 5.7 intake. Shown here with optional fuel rails and throttle body in an EFI application.

Parting the clouds…

IMG_2474

One of the big hurdles I encountered when doing my retro fit…and one that I found a hassle when pondering a change to forged pistons, was what were the parts I actually needed!!

The following list is designed to help the guys who may not have the benefit of an experienced Gen 3 engine builder, but need to get some parts lined up on the table to do stuff.

The list is split into four sections – sections –Basic technical specs of a standard stroke 6.1 hemi rotating assembly – Parts to complete a retro fit using carbs – a list of gaskets and fasteners you’ll need for any tear down or cam change – and some parts suggestions for an internal rebuild  for a stroker or just a stronger standard stroke motor.

These lists are NOT comprehensive, but will at least give you an idea of what’s available and who makes what.

signed, your Editor.

IMG_2806

6.1 Specs

Bore – 4.055

Stroke – 3.58

Rod length – 6.240

Pins – 2.55”, .9843”

Piston weight – 441 grams inc pin


Retro fit parts list

Ignition ECU – MSD 6-HEMI P# 6013 – This is for ignition only. so unsuitable for use if you want EFI.

ECU to coil Harness – MSD P# 88864 (Requires changes to factory cam and crank sensors to 07-10 5.7 Cam and Crank sensors)

Engine mounts – TTI – MM57A

MP Flex plate adapter – P5153753

ATI Flex plate adapter (Recommended) – ATI915685

Milodon Pan/Sump – MIL31000 – (Note, also available are Weldtech, Canton Mecca, Charlies &  Moroso- (Do your research!,Ed.)

Milodon Pick up – MIL18331

Milodon bolt kit – MIL85025

Milodon splash tray – MIL32010

Milodon pan gaskets – Mil40750

Mahle splash tray – OS32363

Milodon Oil dipstick – 22064

Lokar flexible transmission dipstick

Lokar universal accelerator cable

Lokar universal kickdown cable

Manifold – Carb(s) or 4V Throttle Body

  •  OCP Dual Plane Single
  • Edelbrock Dual Plane Dual Quad – (Small plenum volume, responds well to spacers)
  • Ritter Drag pack (Requires scoop – 7.5” high)
  • MP Drag Pack – (Requires scoop – 9” high)
  • Indy Modman – Dual or Single (Recommended for use with supercharger only)

Air cleaner, Aluminium Radiator, Hoses, Electric Fans

PS delete pulley (Bouchillion)

Headers – TTI long tube or Jeep SRT factory may fit

Remote oil filter set up or Dakota filter mount

TTI oil boss block off plate – 0200-FBP

Idler pulley – 0489172AA, Screw – 06508247AA

Tensioner – 04861660AA, Screw – 06104221AA

Jeep 6.1 Nippondenso Alternator pre 2011 – 56044380AC, 56044380AH,  (Use with external regulator) – The Jeep alt. provides for better inner guard clearance.


Fasteners and gaskets

Main Cap oil pick up stud # 6506333A

Main Cap bolt #6506272AA M12X1.75X91.2

Main Cap oil pick up stud # 6506333A

Main cap side bolts #6507697AA M8X1.25X45

Mopar Head Gasket 6.1 #5037592AC

Head Bolt #6506334AA

Head Bolt #6510280AA.

Screw-Connecting Rod #6509243AA

Head Gasket Sets – #Fel-Pro HS26366PT

Intake Gasket (Ports only) – Cometic #C5197 – Cometic Aramid Fibre

Intake Gasket inc Factory valley – MAHLE Original #MS19674

Exhaust Gasket – Fel-Pro #MS96964

Lower end gasket kit – #05170861AC


Std/Stroker rebuild parts.

Pistons – Probe SRS forged – #14868 – 491 grams inc pins – 9.88 comp  – Rings – Total Seal ring pack – CR 1001 60 (1/16,1/16, 3mm).

Piston Kit – Mahle HMI220055F01 forged inc metric ring pack (1.5, 1.5, 3.0) – 429 grams – :10:1 comp

Piston kit – Wiseco K0112xs forged inc metric ring pack (1.2, 1.2, 3) – 460 grams – 11:1 comp

Piston kit – Stroker – Wiseco K471X05 forged inc metric ring pack – 445 grams – 10.5:1 comp

Camshaft – Crower camshaft degreeing bushings – 720007, 720008, 720009 (Use these with aftermarket pistons with valve reliefs ONLY)

T Chain – Manley 73205 DR 9 Key way – (Use with aftermarket pistons with valve reliefs ONLY)

Rear seal without retainer – #C5203 Cometic

Front seal – 53021585AD or Timken SL260028

6.2 / 5.7L – NON-MDS Lifter 5038784AC.

 

11.7 – a win in my book…

Three Years ago I was talked into replacing my broken LA stroker with a Gen 3 hemi.

I figured why not? Easy I assumed.. Run 11s easy I assumed….

Well if you’ve been following…you’ll know it ain’t been easy – but I succeeded through trial, error, bloody pigheadedness and some light bulb moments!

image

If I had my time again…id have gone straight to a hood scoop and a drag pack intake – not because its the best way to make HP with a carb….BUT three years ago it was pretty much the only efficient way. Other intakes on the market were inefficient, or needed more than one carb.

image

If I had my time again…Id know to try to replicate the factory EFI intake….looong runners…and a decent plenum.

So instead…I used stacked spacers

image

Now thanks to Joe O’Cone’s OCP intake, the resto mod is a lot easier… But that wasn’t around when I started.

For me..I had to take the long path  – running dual carbs, a 5.7 intake and a retarded camshaft – it was all about finding the right balance…and I’m still only 3/4 the way there – I’m not made of $$ .

Cam calibration is still a thorn in the side of those doing this mod.  Unless you use custom slugs..it’ll bite you on the backside!

I plan on contacting Modern Muscle next year to see what can be done to defeat Piston/Valve issues without swapping slugs.

image

And then there’s port matching..but now the Eddy dual quad is available with 6.1 ports…for a mere $700 US…..

Until then..I have my 11.7 timeslip to keep me warm 🙂

image

Dyno Data is IN!

Hi all

A while back I promised that Id do a genuine comparison between the Modman intake and the Edekbrock 5.7 dual quad dual plane.

I experienced significant tuning issues with the Modman running both single and dual carbs – (333 RWHP) and it only really worked half way decent when I installed a full height divider (346 RWHP)

Below is the dyno chart ( same dyno..similar atmospherics) showing three (3) runs – 

image

Dyno Dynamics Dyno Chart

The BLUE line was the Modman with divider – this netted a 11.9@ 114mph

The MIDDLE RED is the EDDY – same carbs – 360 rwhp

The Upper RED is the Eddy with twin 1″ 4 hole spacers. – 368RWHP

 

Dyno Dynamics Dyno Chart

The Eddy had a home port match to the 6.1 heads.

I think this proves conclusively that the Modman is a JUNK NA intake.

My guess is that the carbs are losing about 15 rwhp to the EFI….

Going steady with Mopar and EDDY!!

So..

after much testing and trialling of the INDYtm intake which yielded only moderate improvements, I bit the bullet and purchased the EDELBROCK  / MOPAR PERFORMANCE Dual Quad Dual Plane AIRGAPtm. 

Only a moderate change in tuning was needed, the mid range and WOT needed leaning by one step on the step-up rods, and the pump shot set back one step.

The difference has been staggering…with an enormous amount more mid range and far more responsiveness.

Ive found it impossible to get an accurate GTech 0-60 time because the car just smokes the bags all the way through 1st and well into 2nd gear.

I wont be able to provide any statistical comparison until I get it to the track…but Im confident my 60ft issue is no longer going to be induction related……Hooking up may be snother challenge!!!!

image

Eddy dual quad

image

Indy Modman MISERY!!

To speak plainly, Indy Cylinder Heads should be ashamed in releasing such an ill-thought out product on the market, without comprehensive testing including track time.

Peak HP on engine dynos maybe one thing, but its highly doubtful even Indy are aware of what an average performer this piece is in carburreted format.

If you plan on buying a Modman…I’d recommend you use it in an EFI or Forced Induction role.

Single 800 AVS - second best MPH but appalling lean out off the mark - shooter drilled to .040th helped a little

Single 800 AVS – second best MPH but appalling lean out off the mark – shooter drilled to .040th helped a little

The following is a detailed chronology of my efforts to get the Indy Modman intake to work efficiently on my Gen 3 HEMI.

 All tuning changes were validated both on the same dyno and at the track in similar DA.

 I have been tuning Carter and Edelbrock carbs for thirty years and am fully aware of the processes required in re-calibration and enhancements.

1st tune – Single 800CFM AVS Thunder carb

333 RWHP – 110.8 MPH – 12.4 sec qtr – 1.94 60ft

Comment – Lean bog very apparent on launch

 

2nd tune –  Drilled pump shooter to .040th – 1.91 60ft

Comment – No bog if I rolled on the throttle, but sluggish response

 

3rd tune – Pro Systems 830 cfm – 50cc Primary pump shot, 30cc secondary

No dyno – 109.8 mph – 12.4 sec – 1.84 60ft

Comment – No bog but sluggish 60 ft

 

4th tune – Twin Edlebrock 500cfm Performer carbs – drilled shooters to .040th

No dyno – 111.1 mph – 12.39 sec – 1.91 60ft

Comment– Slight bog unless I rolled in the throttle

 

5th tune – Twin Edelbrocks with twin Brodix turtles inserted in plenum

Comment – No change

 

6th tune – Twin Edelbrocks with full height divider along length of plenum – increased initial timing from 15 to 21 deg .  Converted linkage from progressive to 1:1.

348.7 RWHP – 114.3 MPH – 11.9 sec – 1.82 60ft

 

This has been the best result achieved. The 60 ft is still woeful for the mph and HP.

Dual quads 1:1 linkage

Dual quads 1:1 linkage

NOTES

  – Traction not a factor in any testing.

  –  No modification of air bleeds with Holley, just jetting.

  –  The Modman plenum volume results in a significant loss of signal and requires a MAMMOTH pump shot to overcome the overall plenum volume requirements.

  – The full height divider I ran was also ½” wide, serving to occupy some plenum space as well as improve the signal.

 – The car 60 footed better when I rolled on the throttle than when I rugged it in every scenario.

 – Stalling up had a negative effect – often resulting in a bigger bog.  I have determined this was because stalling uses up some of the ‘tip in’ travel hence a smaller pump shot.

 – The cam I ran was a HR with 219@.50 – It does not require a big converter , nor really high gears, so this was not contributing to the issue .

The divider that showed biggest gains. Hard to believe this lump of metal improved MPH by 3 mph!

The divider that showed biggest gains.
Hard to believe this lump of metal improved MPH by 3 mph!

 Summary

On the street, no one would ever guess that these issues were to arise at the track..until I did some street tuning on drag radials.  It was only then I noticed the car struggled to turn the tyres on the street until tune #6.

 This problem manifested even worse at the track.

Conclusion

THE LESSON IS SIMPLE

  • NO intake should perform better with a plank of metal inserted into the plenum.

 

The Modman is a show/supercharger intake – pure and simple.

It may function better with a large cube motor – but as it runs a plenum that is 5x the volume of a normal single plane M1, I would still recommend experimenting with a divider.