Harv's meth monster project

[Harv]

Figured I should finally get around to starting a thread on the meth monster project. I’ve been doing homework and collecting bits for a few years. I need to finish off the wagon (and stop getting distracted by the kids cars), so will keep collecting bits for a while longer.

Overall intention of the project is to build an early Holden suitable for the drags, but is still (just) able to be driven on the street. Power plant will be a 138 grey motor, Norman blown, Repco headed and Hilborn injected. Aiming for dual-fuel: pump fuel for tootling around, and methanol at the track. I am going to try for period-correct (think late 60’s/early 70’s), but only to a point… there will need to be some concessions to modern safety. I recognise that this thing is likely to be a pig to drive on the street, but can also imagine driving to the shops, with the car struggling to idle, and me with a huge grin. Take it to Eastern Creek, and flog the snot out of it until something breaks. Think of it as an old hoon’s project .

Aim of the project is to use my FB daily driver and retain NSW road rego. The modifications I am planning will need engineering, so I’m going to have to dial the engineer in pretty soon (about the same time that I get the wagon final engineered). I want to make the minimum of change to the vehicle that I can, and still make engineering (e.g. I will need to go disk brakes, but am not intending to go HR front end).

I’ll share some of the thinking as I go along – aiming to dispel some of the old Holden myths along the way.

The intention is to take one of my spare seized grey motors and have it rebored. I initially figured on boring the thing out as far as I could (you can’t beat cubic inches) and using the JP Performance part number 0196 pistons (3¼” bore). This would take the grey out to 156ci. Some research with the lumpy humpy crowd shows that this is perhaps not the smartest move. The JP pistons are sand cast and heavy. They are unlikely to take the kind of abuse that I intend throwing at them. Instead, my intent is to get some pistons made up by Special Piston Services. They will make up a forged set. There are a couple of advantages:

a) The forgies will take a lot more abuse than the cast pistons.
b) I can customise the pistons to suit valve clearance and compression ratio I am targeting (being a blown motor I need to be careful around over-compression). Compression ratio will depend on cylinder head volume, which I can’t work out until I CC the Repco head.
c) I can use fancy modern rings for a better seal. To do this, the trick is to use a metric bore size (there are a lot more ring options in metric). The standard Holden grey motor 138ci engine block is 3 1/16” (77.7875mm).
• 10 thou over is 78.0415mm
• 20 thou over is 78.2955mm
• 30 thou over is 78.5495mm
• 40 thou over is 78.8035mm
• 60 thou over is 79.3115mm

I will bore to 78mm (or 78.5mm) depending on what the bore looks like once it is apart.

So for now I need to get the old seized motor out, get it apart and get it bored while I wait for the head to be finished. Pistons to follow.

Cheers,
Harv

[59wagon]

Wooohoooo!!!!! Looking forward to this one, Harv!

Giddy up, giddy up, 138

Cheers,

John


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[Harv]

For the meth monster crank, I had a few options. The grey crank is known to have a harmonic at around 6200rpm. Holding the crank at this speed can lead to catastrophic crank failure. I also have a speed limit on the Norman of around 6,000rpm… above that speed, the supercharger efficiency drops off (due to slippage around the vanes) and I start to make more heat than boost – I will need to manage this carefully with pulley ratio dependant on what the final redline is.

To give myself some options on crank speed, I need a more robust setup than the standard crank. The Vauxhall crank conversion gives increased strength, though needs machining. Whilst the machining is not a show-stopper, finding a Vauxhall crank is pretty tough… they are rarer than rocking horse poo. There are also billet cranks available, but I was scared off by the price (~$5000). One option is to use main cap bridges. These bolt over the main caps, and provide extra stiffness for the bearing area. There are a few people who know how to make these, though no detailed drawings are in circulation nor anyone making them commercially (afaik).

I took the option of installing a Sonic crank girdle (https://www.sonicinjection.com.au/index ... ud-girdles). These bolt up to the bottom end, and provide similar reinforcing to the bridges. The only drama is that the girdle fouls the oil pan. In my case that is not so much of a drama, as I have plans for the sump (more on that later).

Given the propensity for cracking, I need to have a good conversation with the machine shop before the crank is worked. I’m guessing that crack testing (mag particle, dye pen etc) will be on the cards, though not sure whether it will get shot-peined to reduce surface stress risers.

On the crank snout I was not overly happy with the original harmonic balancer. The rivets are known to fail, and I have had my share of wobbly balancers. There are replacement balancers available via Rare Spares, though they are a relatively similar construction to the original. I have gone with a Ross Tuffbond 116543 Metal Jacket Balancer (https://rossperformanceparts.com/produc ... ic-damper/). I like these balancers because:
a) they are a lot more robust than the other reproduction balancers,
b) they have timing marks etched into them. By bolting on a simple timing tab I will be able to check timing a lot more easily than by looking at the flywheel.
c) they have three bolt holes that will allow me to bolt up a gilmer drive pulley (they are M8 though, not like the imperial threads in the other repros).
d) They have a steel outer ring. I suspect the original and repro balancers have a cast outer ring. ANDRA General Regulation 4.4.4 requires a scattershield for cast outer rings. The scattershields get cumbersome with gilmer belts, oil pumps, timing tabs etc hanging off the snout.

The only problem I have found with the Ross balancers is that they are very, very tight on the crank (they are labelled as an ISO H7 fit, but not what subset of the H7… I suspect s6 as they require a dreadful amount of belting to get them on). I’m intending on getting the crank snout pilot drilled and tapped to suit an installation tool (similar to this: https://www.ebay.com.au/itm/Proform-665 ... 2130565963). The machine shop can then adjust the clearance down to the point that the installation tool will work. No more need for the knockchrometer. The snout tapping will also allow me to fit a balancer retaining bolt, as required by ANDRA General Regulation 4.4.4.

Cheers,
Harv

[Harv]

For the connecting rods, there is a good argument to use the original GMH rods. They will stand up to a fair amount of abuse. I figured on going for a lighter and stronger rod, and ended up using the Eagle CRS5900MCXD connecting rods.

These are made to suit the Mitsubishi 4G63 motor. The 4G63 was a 1997cc 4-cylinder engine produced in both naturally aspirated and turbocharged form from 1980. It continues in use with some Chinese manufacturers, and was used to power the Lancer Evolution when Tommi Makinen won his four consecutive WRC championships (the grey motor block will grenade before I break these rods ). Early versions of the 4G63 (prior to April 1992) used thicker con rods, smaller gudgeon pins, a broader big end width and six bolts to secure the flywheel to the crankshaft (later versions used seven bolts). Eagle offer five different forged H-beam rods for the 4G63, all of which are 5.9” long, 45mm rod journal, 48mm housing bore, are fixed with ARP bolts and exceed ASME E-4340 steel standards. Most use the later 22mm gudgeon pin diameter (not a problem for me as I am using custom pistons). The rods are available as either standard, or extreme duty. Typically the early 6-bolt rods (like my CRS5900MCXD’s) are used on genuine Holden grey cranks, though need ~0.008” surface facing to fit in the throws. The later 7-bolt rods are normally used on the aftermarket billet grey cranks, as the reduced big-end width provides less crank stress.

Engine Duty Part No. Weight Pin Size Big end width
Early 6-bolt Standard CRS5900MA3D 575g 21mm 1.117”
Late 7-bolt Standard CRS5900MB3D 575g 22mm 1.038”
Early 6-bolt Standard CRS5900MC3D 585g 22mm 1.117”
Late 7-bolt Extreme CRS5900MBXD 580g 22mm 1.038”
Early 6-bolt Extreme CRS5900MCXD 585g 22mm 1.117”

One of the challenges in buying aftermarket 4G63 conrods is that they are a 4-cylinder engine… so everyone wants to sell you sets of four. CNC Motorsports (based in the US - http://www.cnc-motorsports.com/) will make up a set of six rods.

Cheers,
Harv

[59wagon]

I don’t think you’re talking this project seriously enough, Harv - you need to do more research .....

Seriously though, I find this fascinating and it’ll help me learn more about the intricacies of engines. Thanks for taking the time.

Cheers,

John


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[ardiesse]

Harv,

I am watching with interest. You wrote -

"c) I can use fancy modern rings for a better seal. To do this, the trick is to use a metric bore size (there are a lot more ring options in metric). The standard Holden grey motor 138ci engine block is 3 1/16” (77.7875mm).
• 10 thou over is 78.0415mm
• 20 thou over is 78.2955mm
• 30 thou over is 78.5495mm
• 40 thou over is 78.8035mm
• 60 thou over is 79.3115mm

I will bore to 78mm (or 78.5mm) depending on what the bore looks like once it is apart.

So for now I need to get the old seized motor out, get it apart and get it bored while I wait for the head to be finished. Pistons to follow."

My two cents's worth: a seized motor will have at least one rusted bore, which won't clean up properly with a 78 mm bore (it's only +0.010"). Go on, shoot the works: 80.0 mm, close enough to 3-5/32".

The next point needs to be approached with some diffidence . . . an FB, and shall we say, avoirdupois . . . from a "weight is the enemy" standpoint the late '53 48-215 would appear to have the edge. But I'm aware of what forum I'm presently commenting on. So, hey, why not an FB?

If you want acceleration off the line, I know where you can get a 4.8:1 diff . . .

Rob

[Harv]

My two cents's worth: a seized motor will have at least one rusted bore, which won't clean up properly with a 78 mm bore (it's only +0.010"). Go on, shoot the works: 80.0 mm, close enough to 3-5/32".

You're right, the siezed ones are likely to be pretty rough. I have a spare running engine (my test mule), but was going to avoid using it for the meth monster project... it is the "emergency spare" in case Grace's ute or the FB crap out one afternoon. The siezed ones were sad. I bought them off a bloke in Smithfield who advertised they were stored under cover. Showed up to pick them up, only to find them out in the rain with the rocker covers open. He was moving house, and wasn't too fussed. They had been outside for a while, all locked solid. Grrrr......

80mm is 87 thou over. I had a mental picture that 60 thou over was pushing the limits. I had one of the old Holden myths in my head - 60 thou is nearly on the water jackets, core shift in the old blocks means you may strike water, the walls end up too thin and you get heat spots etc. Your post made me think - this project is about challenging some of those old myths.

The more I think about it, the 3 1/4" pistons that JP sell are nearly 190 thou over... so 80mm/87 thou is not so bad. So looks like I've made the decision - 80mm bore, giving the old grey a 146.1ci capacity (giddy up 146 ).

The next point needs to be approached with some diffidence . . . an FB, and shall we say, avoirdupois . . . from a "weight is the enemy" standpoint the late '53 48-215 would appear to have the edge. But I'm aware of what forum I'm presently commenting on. So, hey, why not an FB?

I'm figuring that before I start, the FB goes over the weighbridge. She then goes on a diet. Maybe not so extensive as Harrops Howler (more holes drilled than your average colander), but should be able to drop quite a bit. I've got moulds for fibreglass doors, bonnet, boot and guards (damn I've collected some crap for this car over the years ) so this may be fun.

If you want acceleration off the line, I know where you can get a 4.8:1 diff . . .

It's going to be interesting to see how the FB goes with only 3 cogs to play with. Not sure whether it will be slow off the line, or will run out of legs in the top end. I've (almost) got a 3.55 LSD centre lined up. Got some more research to do to see if I can swap fine-spline ring gears and pinions onto coarse-spline carriers (http://www.fbekholden.com/forum/viewtop ... 26&t=21905). Interested to hear how much the bloke is after for the 4.8:1 centre though .

Cheers,
Harv

[Harv]

For the “other end” of the crank, there is probably no real reason not to use the original flywheel. These can be machined (lightened) by most machine shops. The lightened flywheel allows the engine to change revs quicker (a good thing). The lower inertia of the lightened flywheel means that outside infleunces (eg hitting small hills, engaging the clutch) can have more effect on engine revs (not always a good thing). For the meth monster, I ended up going for a Direct Clutch Services billet steel flywheel to replace the original cast item. One reason for doing this is that ANDRA General Regulations 2.9.6 also prohibit excessive machining of flywheels.

The same Regulation also indicates that anything running faster than 11 seconds must run a steel or alloy flywheel. The chances of the meth monster breaking into the 10s is nil. I’m not sure what the fastest pass ever achieved with a grey was (anyone?), but as a guide Harrops Howler ran 11.8s with a red. If I can get this thing down into the 12s I will be pretty happy. The direct clutch services flywheel weighs 8.6kg, and may need a bit more of a skim before final assembly.

Cheers,
Harv

[NoMAD]

Really enjoy reading all this Harv... Is an awesome project.

Cheers
Nathan

[59wagon]

So looks like I've made the decision - 80mm bore, giving the old grey a 146.1ci capacity (giddy up 146 ).

Can you push it out to 149, Harv? It’s a better sounding lyric than 146 in the song, that’s all


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[ardiesse]

Gentlemen,

149 cubes in a grey is 3-3/16" bore, which is considered the practical maximum for B and J blocks (my "test mule" engine is 3-3/16").
Supposedly the early and L blocks have a recommended maximum bore size of 3-1/8".
Maybe, just maybe, if you have a well-cast block with no porosity, no core shift, and bugger-all corrosion in the water jackets, you could go 3-1/4".
I think the guys who went 3-1/4" bore sleeved the bores more often than not.

Rob

[Errol62]

I was wondering when the subject of sleeving would come up so thanks for raising it Rob. I don’t know anything about this but I have been wondering for a while whether it would be feasible to fit considerably larger sleeves to a grey block. There is no replacement for displacement as they say. I recall reading about later Australian sixes having the castings entirely replaced with forged barrels. Rigidity of the block and bore centre separation being the obvious limitations, I wonder if this has ever been tried or considered. Realistically most things have in the last 70 years since the first grey.

The example I recall was a mechanical engineer who modified a red block, canting the bores so that they were closer to parallel to the con rod on the down or power stroke, dramatically increasing efficiency. This motor was installed in an EJ sedan as I recall with 2.78 diff and very large diameter rear wheels. The motor produced massive torque at very low revs so quite the opposite to what you are intending Harv. None the less it is more the idea of getting a larger bore out of the grey that is relevant to this conversation.


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[ardiesse]

Clay,

Joel Wakeley's book "Legends of the 48-215" had a long discussion about what the Boomerang Garage in North Strathfield did to the racing Humpy that Spencer Martin drove. In that block all six bores were sleeved, and if I remember right, they bored the sleeves out to 3-1/4" + 0.030" (so effectively 3-9/32" bore, for 158.5 cubes).

Red motors are off-topic a bit, but Harv will forgive the indulgence.
A quick way to get more oomph out of a red motor is to install the pistons backwards on the con-rods. This reverses the piston pin offset, and produces much more favourable con-rod geometry during the power stroke, at the cost of faster bore wear. Another, similar trick is to offset the boring bar to the left side of the block when re-boring, as this also improves the con-rod geometry on the power stroke (and this trick is applicable to greys as well). It's not quite the same as canting the bores, but has a similar effect.

Harv - if you're getting pistons custom made, maybe you could look into getting them with a certain amount of piston-pin offset, even though grey pistons don't have any in stock form.

Rob

[Errol62]

Thanks Rob
159 Harv, she’s real fine my 159........


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[Harv]

Hmmm.... the 159 has an 83-odd mm bore. Methinks I might do a little talking to the machine shop (Duncan Foster) and see if I can find a sleeve size that matches well with a metric bore.

Cheers,
Harv