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you can see in dish size between 5/71 and the late 71 engine how rare the red devil 400 is,yank expert says thats why no emmisions sticker available because low numbers were ever made,possibly only a month or 2 then low comp pistons fitted,there is another rare 400 with small block bolt pattern 1973 only and engine mounts are same as ours,then they went back to big block pattern ,very weird .

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you can see in dish size between 5/71 and the late 71 engine how rare the red devil 400 is,yank expert says thats why no emmisions sticker available because low numbers were ever made,possibly only a month or 2 then low comp pistons fitted,there is another rare 400 with small block bolt pattern 1973 only and engine mounts are same as ours,then they went back to big block pattern ,very weird .
Gerg you still want it $300 4423063e9a63e4547d7f12823e2c6f51.jpg85ed7e73159f91b8f1775fa46388af89.jpg

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already have a bid of $1600 lets see what we can get for it
Got 1600 for it ,going to Tassie ,todays trip to the machine shop i found an old d2ae std bore block and olm8 is going to dip it in citric acid to remove rust for 200 bux so i will grab that for next build486f9d7ac0727848f01919d319e03b87.jpg

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the 400 is going in a linkin continental limo lol 
Also he dont need those nice exhaust manifolds as he is gunna use his old 400 gear on it ,eg sump and exhaust.

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@CHESTNUTXE, I'm at the beginning of resurrecting a Cleveland in an F-truck, which is running poorly.

you may be able to offer some advice?

 

Nick the owner (a family friend) knows nothing about the build.

It's in a late 70's F150 4x4, with 4 spd manual F-truck gearbox/transfer case.

 

The engine runs straight LPG, with twin Impco 225 gas converters, on a high rise AFR intake manifold.

I can't find any info, on the intake manifold though?

 

The exhaust comprises of Genie 4-2-1 Stainless Steel extractors, 2.5inch collectors, no cross-over pipe,

and one chambered muffler on each pipe, with short downturns under the tray, prior to the rear diff.

 

Last weekend, I did a compression test, and measured the piston stroke

It's a 3.750 stroke.

The dry compression varies wildly, from 180, down to 150psi,

and jumps to 250-ish PSI, wet.

 

It has a Scorcher distributor in it, (timing unknown atm, but vac advance is blocked off)

Spark plugs are NGK BP5FS's.

 

It's very down on power, IMO - feels like mid 250-ish hp, if not less.

 

Suggestions?

 

Reckon I should start a separate thread?

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With an .030 bore that roughly equates to a 383 cubes, could be one of the older offset ground stroker crank setups, if it was done here it would most likely be a pro stroke kit using an offset ground 351 crank

 

 

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[mention=7196]CHESTNUTXE[/mention], I'm at the beginning of resurrecting a Cleveland in an F-truck, which is running poorly.
you may be able to offer some advice?
 
Nick the owner (a family friend) knows nothing about the build.
It's in a late 70's F150 4x4, with 4 spd manual F-truck gearbox/transfer case.
 
The engine runs straight LPG, with twin Impco 225 gas converters, on a high rise AFR intake manifold.
I can't find any info, on the intake manifold though?
 
The exhaust comprises of Genie 4-2-1 Stainless Steel extractors, 2.5inch collectors, no cross-over pipe,
and one chambered muffler on each pipe, with short downturns under the tray, prior to the rear diff.
 
Last weekend, I did a compression test, and measured the piston stroke
It's a 3.750 stroke.
The dry compression varies wildly, from 180, down to 150psi,
and jumps to 250-ish PSI, wet.
 
It has a Scorcher distributor in it, (timing unknown atm, but vac advance is blocked off)
Spark plugs are NGK BP5FS's.
 
It's very down on power, IMO - feels like mid 250-ish hp, if not less.
 
Suggestions?
 
Reckon I should start a separate thread?


I agree with everything Thom has said. It will likely be running Chev stroker pistons and rods, maybe the rings aren't so happy now?

Twin 225s ain't much carby for a big donk like that. You would want to see twin 300s or even 425s to get the most flow possible to feed it.

The ignition needs more initial, less total timing compared to petrol.

I take it that the AFR manifold is a single 4 barrel with an adaptor for the Impcos?

How is the gas tune? It's very hard to sense if timing is advanced or retarded, or if the gas is rich or lean, because it's really hard to get it to knock and it can get very lean or rich before any obvious symptoms show.

One major thing, gas takes up 20% more volume in the intake than petrol does, so your effective flow for a given size port is less. Your cam and port size need to be increased by the same amount to match the power of petrol (all other things being equal). So if only running 2Vs, maybe they need a bit of work?

So all this coupled with some cylinders being down on compression may all conspire to give the lacklustre performance you're seeing.

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Just looking up specs, the 225 is rated at 329cfm at 1.5"Hg (4 barrel standard), so 2 of them is 658, or close to a 650 Holley. Now that would be too small even for a petrol 383 stroker.

 

That coupled with the extra flow requirements definitely shows that more carby is needed, more like 800cfm. 2x 300s gives 432cfm each, or 864, bang on the money I reckon.

 

A single 300A is rated at 217hp, so naturally, 2 of them would be double, about what you're shooting for, correct?

 

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8 hours ago, gerg said:

Just looking up specs, the 225 is rated at 329cfm at 1.5"Hg (4 barrel standard), so 2 of them is 658, or close to a 650 Holley. Now that would be too small even for a petrol 383 stroker.

 

That coupled with the extra flow requirements definitely shows that more carby is needed, more like 800cfm. 2x 300s gives 432cfm each, or 864, bang on the money I reckon.

 

A single 300A is rated at 217hp, so naturally, 2 of them would be double, about what you're shooting for, correct?

 

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I really don't know what a sorted 383ci combo is capable of tbh, but I'd assume circa 450hp?

 

IMO, it needs to be a torque monster, rather than an RPM queen.

I'm not sure yet, if the manifold is single or dual plane.

 

From what I can gather, the engine was built about 12yrs prior - from a couple of owners ago...

Nick tried to get build info when he bought it 4yrs back, but the previous owner knew nothing,

nor had the details of the owner before that.

 

My next task, is to suss out the cam... it sounds cammed, but again - no info.

I pulled a rocker cover off last weekend, and it has standard rocker gear, but appears to have better than stock springs - spring/damper.

 

The compression does have me slightly concerned... at idle, it fumes out the oil cap, like a mini steam-train.

Nick had a catch can fitted by his normal mechanic - which is open to atmosphere, with a hose going to each rocker cover.

(no PCV, and second hose in place of oil cap)

 

His mechanic recently gave up on the vehicle, suggesting he find a Ford guru, and saying they're only good with newer vehicles.

My name got suggested somewhere through the grape-vine, and here we are.

 

I went over the whole vehicle last weekend, and honestly it's a basket case...

Steering and suspension issues, leaking brake master cyl, worn front hub bearings, the engine issues and more.

A succession of poor quality parts, dodgy workmanship plus normal wear and tear.

 

Being a 4x4 F-truck, its still worth repairing, IMO.

 

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"Still worth repairing" is a very subjective statement. In the hands of someone who is on to it and can diagnose and do the work themselves, it may well be worth it, but if he needs to go to a mechanic every time something else fails, then maybe a 40-odd year old truck is not for him.

Choofing fumes out the breather is not a good sign, it will definitely lose compression at lower rpm where it is most needed in a truck.

The block could well be a basket case if it's worn out and already gone +30 on the bore. If it's only broken a ring or scored one or two bores, it might be worth sleeving, but 383s are pretty poor for rod/stroke ratio. 1.52 is definitely in the lower end of an ideal ratio. It might just be a worn piston so he could be lucky there (if you can call an engine overhaul "lucky") and not have worn the bore(s)

Really, if it's been on LPG the whole time, you would expect bore or piston wear to be the least of your problems. Being a dry fuel, there is no oil dilution, just pure oil on all parts. There is the issue of acid buildup in the oil over time, but that mainly causes bearing erosion.

The fact that it's been through several owners is a problem too, you don't know how much it might have been neglected or thrashed.

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I would expect a mild 383 on gas to put out low 300s hp with stock, untouched ports. Mid to high 300s hp with some good porting and well matched cam. That would be a good midrange engine for a truck.

Cracking 400hp needs lots of flow, enough gas to feed it (including converters), some decent rpm on board, and a very good port job, like the one Pavtek offers with CNC porting (quite decently priced actually).

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A dyno measures torque, and also measures rpm. Torque x rpm is horsepower.

I wouldn't dyno it just yet. Let it free up a bit first. A tight engine will be down on power for the first couple of thousand km. It also might run a bit warmer and use more juice.

Have you dumped the run-in oil yet? Probably a good idea, and then run a quality oil with zinc in it. Fuchs Titan 20W60 is what I ran last time, probably a good choice up where you are in banana bending country to run something thicker in the warmer climates. I have chucked 15W40 in mine with some Rislone zinc additive, as a decent zinc oil is hard to get in a more winter-friendly grade (for Sydney).

I only advise this because I've wiped 2 cams in only 80,000 km. Oil manufacturers don't care about the 1% of cars needing zinc oil for their flat tappet engines, so it's up to us now to come up with the solution. I wouldn't want your build to go pear-shaped after all this work.

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Agreed.  I'd give it 1,000 kays at least. Bed in the rings and cam, let all the seals swell up and do a couple of oil changes. Tell your dyno guy what rev limit he MUST stop at.! 

4,500 or 5,500 and thats it, even if he says theres more in her......

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Agreed.  I'd give it 1,000 kays at least. Bed in the rings and cam, let all the seals swell up and do a couple of oil changes. Tell your dyno guy what rev limit he MUST stop at.! 
4,500 or 5,500 and thats it, even if he says theres more in her......
I changed oil last night nulon zinc 25 60w

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For once im on the opposite side of the argument from bear and gerg, personally I like to put a fresh engine on the dyno as soon as possible, the dyno can be used as a tool to properly bed rings in quicker and easier than it can be to do it on the street, also you can get your carb and ignition tuning correct usually with less trial and error than street tuning in the first few 100ks

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