Are you Bored? Bang for Buck Engine recipe required.

[ed.harris]

Hi Guys,
When I was young I had an LC GTR Torana with a 161S Engine opel Gearbox, they made 125 HP at 4800 rpm. 9.2-1 Compression ratio.
It was standard, it had 2 barrel, GTR headers. slight lope and nice sporty power.
The Torana weighed 1013 KG. My 1955 FB Holden Ute weighs 1012KG.

I would like to replicate that power (115-125HP) in a Grey Motor.

slightly more lope is OK but I don`t want to spin the Grey motor above 5800rpm.
I will be fitting one of 2 Opel gearboxes behind the Grey Motor and change the diff ratio to either 3.55 or 3.36.
The tyres are 205/60/13.

So I have a J motor that looks like it has Original paint on it, I have not pulled it apart yet.
It turns over and plug no6 is oily.

I intend getting the head overhauled and modified as much a practicable by Galloway Engines in WA, and other machining where required.

I am not sure if Higher Compression pistons are required to get that power and still be flexible down low rpm.

Or... if Shaving the head past the thumb print and zero decking the block is enough to get the required power ( how much to the compression change/).

I plan on running a Clive 82 or similar Cam, evil bay SS Extractors, twin Strommies with matching Oil bath filters in my 1955 Ute.

I would like to not run roller rockers if possible.= and basically keep bottom end stockish as it wont be spun up, ..... much...

Does anyone have dyno results and Engine recipes to accomplish the target Horsepower required?

General overview Good top end on reasonably stock bottom end, if that is possible for the power required.

I will probably screw the thing together myself.
Does any one have any lump tops?
I am bludging at work so I might have missed a couple of details.

Cheers Ed.

[Errol62]

Hi Ed,
May be shot down here, but I think that 125hp was on the generous side, considering the 2600S was stock. Nonetheless it will be a fair challenge to bring the EJ motor up to similar output, considering the disparity in cui.


FB ute fixer upper, EK van on rotisserie

[Blacky]

There is a YouTube video of a grey motor that was pretty close to the specs you listed that made around 120 - its a street machine magazine video I will see if I can find it and post the link

[Blacky]

https://www.youtube.com/watch?v=VLFrclJ690A

..... of course your other option is to follow along on one of my latest projects - which involves forced induction

[ed.harris]

Thanks Blacky,
I will have a look at the Video later tonight when the Boss is not looking.

In regards to increasing Cubic Inches, Galloway do a Stroker Crank, Rods etc that will increase the Grey Motor to around 160 CI.
While this will make easy to achieve the Goal HP and have a very smooth Engine, I did a quick calculation and a high Compression Rotating assembly alone would cost around $11,000.00.

I did speak to David at Galloway Engines about 12 months ago and he did say that he believes the EJ J motor had the best Block casting and Main caps, the Best Head casting and I think he said, a better crank, and of course, is the youngest type of Grey motor.

I am hoping I have a good base J motor that does not have cracks or already oversized too much.
I will find out soon when I break it down.

I have been thinking about this build for a while, most of the old speedway guys have gone with the knowledge they had in their heads, so now, we have to use a combination of that and new improvements developed by companies like Galloway and HSD.

Then there is the other guy that throws together a bunch of random, scavenged, second hand parts, and makes a Freak Rocket of an Engine on the cheap.
The Hot Rod guy, with or without help from his friends.

I want to start with the head and Induction system to try and Jam as much charge into the Cylinder as possible.
The question is what compression ration is required for the smoothest running Engine, but still achieving the goal?
I believe the J Motor is 7.25 : 1 Compression ratio.
How much does Decking the block to zero deck height and shaving the head past the Thumb print increase the Compression ratio?
Sideplate sealing issues also need to be addressed, water pump fouling maybe?

Cheap bump up pistons would be great.

I have not played with grey motors before and have read about bottom end vibration issues and how important a good balance is.
This is mainly due to antiquated machining and manufacturing of the era.

I have read that the Standard Rod weights can vary in the Grey Motor quite a lot.
Does throwing H beam Rods at the Engine solve most of the issue?
Piston weight cannot vary too much.
whack on a modern Balancer, the standard one is substandard.
How badly out of balance is the Crank.
I only want to spin it to 5800 rpm max.

Just thinking out aloud.
Looking forward to viewing the Video.

Anyone`s thought or experiences shared will be appreciated.

Thanks Blacky.
Ed.

[Blacky]

Harv is the resident grey motor - and anything else mechanical for these things - guru.

I am sure he will chime ion sooner rather than later. Mark Reik has explored the outer limits of grey motor metallurgy by shoving 20lb of boost into one with the result being what you would expect .......... he uses Mitsubishi rods and aftermarket pistons - cant remember what they are

[ed.harris]

Thanks Blacky,
Yes, I am aware of Harv`s Guru Status, having Purchased 3 of the High Duty Head Gaskets though Harv.
I have spent many hours reading 0.01% of his Posts, on Various Forums, his name pops up everywhere.

I am sure I will be asking his assistance when sorting out the half a dozen BXOV-1 Carbs I have in a Box choosing the best internally functioning ugly looking Carbys to modify for the Twin Set up.... Hmmm Venturi sleeves... 48??? 67?? I forget now... doohickies, thingys... power valves?

I watched the video didn`t glean much technical info.
Cam 220@50.. I`m not sure.
Compression ratio 9.5 to 1, How was that achieved?
I think it must have dome top Pistons.
They are not going to give away their secrets. Their V8 Build packages seem quite thorough.

I cant see milling the head achieving that sort of increase from 7.25 to 1 standard comp ratio.
I am not sure, but it sort of makes sense with such a mild Camshaft.

I prefer not to mill the Head too much as I have visions of repairing sideplate Oil leaks bending over the fender after removing the Dissy, Oil filter, Battery, battery box etc.... and still not fixing the leak and reattempting the repair a few times.

Do other guys have problems with Sideplate oil leaks after Milling so much off the head and Block?
Elongating holes.... you would Elongate the lower holes ??? right?? so the Spark plug cork Gaskets remain in their correct location, and they dont leak??
Tin Snips or grinder... Oh, I dont Know...
Or am I just over thinking it??

So it is Achievable.
Although I think Forged Custom Pistons are around $2500.00 for six pistons.
This obviously affects whether the head will be milled or not, quite a substantial Cost though.

The quest continues... on a budget.
thanks Blacky.

[Blacky]

"power" and "budget" are rarely seen together when it comes to the old grey donk sadly .......they are second only to the flathead frod engine as far as the dollars in = power out ratio is concerned.

[Harv]

I'm no engine guru - there are plenty on here who know far more than I do (nods to Messrs. Rod and Craig, amongst others).

A lot of the puzzle comes down to intent - what do you want it to do, and how reliably do you want it to do it? Summarizing the text above:

115-125HP in a grey motor (doable).
Slightly more lope is OK (I suspect you may hate the Clive 82 cam. I put one in Grace's ute, and it is a pig around town. In an NA car, you may need to live with this to some extent, though you do want to be "flexible down low rpm").
I don`t want to spin the Grey motor above 5800rpm. (sensible choice to avoid making large, irregular sized welch plugs).
J motor, not pulled it apart yet but turns over (good start. better bearings and has dizzy gear oil hole. The age benefit of a J vs FJ-FE block is a furphy. Js are 63, the rest only 20 years older. Some got flogged, some bored, some not. Its a lucky dip... I can do more damage to a pristine J block running it as a boat motor for 6 months than an extra 20 years of age damage. Big issue here is the crank... take it out, take it to Galloway and get it measured and crack tested. Cracks mean you are hunting a new crank... I pulled down around 6 engines for my meth monster project and from memory 2 were cracked. Undersized means you may not be able to machine it down any more, and are again hunting a new crank).
Intend getting the head overhauled and modified as much a practicable by Galloway Engines in WA, and other machining where required. (Galloway are good, and if you are localish this avoids freight. Consider either getting them to design up the whole package. Another option is to use a head from HSD in Victoria. Suspect their headwork is better than Davids. He has experience mating their work to his own.).
May need higher compression pistons (probably, though this is where it gets pricey. SPS in Victoria will make you a forged set that will get you up from facgtory 7.25:1 to around 10:1 for more power but still 98-fuel friendly, assuming you do not want the hassle of methanol or E98. You may find a set of old cast lumpy top pistons, but expect a search of several years and a price that is probably 3/4 that of SPS ones).
Evilbay SS extractors (OK)
twin Strommies (also OK)
matching Oil bath filters (not if you are looking for grunt).
not roller rockers (dont need them)
keep bottom end stockish as it wont be spun up, ..... much... (depends on how you spin it. Driven sensibly (whatever that is ) the stock bottom end is OK. If you are intending on drags, red light warrior work or tractor pulling then the crank is the weak link. Spanners experience is around 120 passes before he cracked one. Forged cranks are very expensive, and need the block machined to suit them).
Sideplate sealing issues after shaved head (mostly not an issue, elongate the plug holes a little if needs be, go heavy handed on the sealant on the cork seals)
Water pump fouling after shaved head (nope - lots of room to either skim the pump or shim it).
Bottom end vibration issues (not a problem unless you are running it hard, other than the harmonic at around 6200rpm which is above your maximum speed limit. Run a new balancer in any case. The Dayco ones are fine for what you are doing. The Metal Jacket balancers are pricey and need the crank machined as they are too tight an interference fit on the snout).
Standard rod weights can vary in the Grey Motor quite a lot (not hard to find a set that is close then machine them down to match. H beam rods are expensive and not needed for what you are aiming for).
Piston weight cannot vary too much (same deal - machine down until they match).
"Power" and "budget" are rarely seen together when it comes to the old grey donk sadly .......they are second only to the flathead frod engine as far as the dollars in = power out ratio is concerned. (grey motors are a very expensive way to go fast slowly).
Venturi sleeves... 48??? 67?? I forget now... doohickies, thingys... power valves? (yes to all of this, but tuned to suit the engine you build once it is running. I can lend you the tuning kit).
visions of repairing sideplate Oil leaks bending over the fender (if there ain't no oil under it, there ain't no oil in it).
plus... new plugs/points/leads and dizzy examined/potentially regraphed, new water pump, overhaul oil pump, clean radiator and high flow thermostat, test and perhaps new coil,,,

Cheers,
Harv

[Craig Allardyce]

Honestly in my experience with grey motors, if you want to go for more horsepower within reasonable costs you are better off supercharging the engine. With as much porting improvements you can do to the asthmatic head you wont achieve much, but with a blower on top you are better off.
This saves stuffing with high comp pistons. With mild boost of around 5-10 psi you should achieve your mark. That will be at a lower rpm as well.
Moderation is key, build the best NA engine you can or want, then blow it! Keep blower speed and boost down to reduce intake charge heat.

[Blacky]

Honestly in my experience with grey motors, if you want to go for more horsepower within reasonable costs you are better off supercharging the engine. With mild boost of around 5-10 psi you should achieve your mark. That will be at a lower rpm as well.
Moderation is key, build the best NA engine you can or want, then blow it! Keep blower speed and boost down to reduce intake charge heat.

This

This is what I was alluding to in my second post on this subject - A mate and I are in the very early stages of building a turbocharged grey motor - I bought another wreck today and its going to be a test bed to build a turbo exhaust manifold for a simple blow through setup - although there has been quite a bit of talk lately about an EFI conversion as well . Once we do something concrete I will start a thread to put all the steps together.

[Craig Allardyce]

My next build will be a blown grey for my boat. It will be methanol fed as it will be seriously leaned on.

[Harv]

My next build will be a blown grey for my boat. It will be methanol fed as it will be seriously leaned on.

With the crossflow?

Cheers,
Harv

[Craig Allardyce]

My next build will be a blown grey for my boat. It will be methanol fed as it will be seriously leaned on.

With the crossflow?

Cheers,
Harv

No it will be a standard head sort of. New alloy construction hopefully, and way cheaper than the going the cross flow route.

[Blacky]

No it will be a standard head sort of. New alloy construction hopefully, and way cheaper than the going the cross flow route.

Young Mr Allardyce, you KNOW you cant make a statement like that and provide no more info - do tell ????