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Compression readings and assessment


Jeff Balazs

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Hey Guy's;

What sort of compression numbers should you expect to see on a freshly rebuilt 218 or 230? How about with a shaved head?

I am attempting to assess the future of my trucks engine situation. I would really like to have some more power on tap and am thinking about either going to split headers, better manifold and carbs and shaving the head a bit or possibly putting in a V8 and different transmission.

I would prefer to stay with the existing set up. So what I am trying to do is assess the actual condition of this engine and how much power I might be able to gain with a rebuild and the kind of mods I have mentioned here. I would think that if I could gain say 25hp that this would make a substantial difference in the way the old truck performs. This engine is a 54 230 truck engine and currently runs well.

One thought I have had is to begin by making the mods to the exhaust and intake systems and see if I get enough of a gain in power to go further with it.

 

I would appreciate any thoughts you may have on this.

Jeff

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Hey Guy's;

What sort of compression numbers should you expect to see on a freshly rebuilt 218 or 230? How about with a shaved head?

I am attempting to assess the future of my trucks engine situation. I would really like to have some more power on tap and am thinking about either going to split headers, better manifold and carbs and shaving the head a bit or possibly putting in a V8 and different transmission.

I would prefer to stay with the existing set up. So what I am trying to do is assess the actual condition of this engine and how much power I might be able to gain with a rebuild and the kind of mods I have mentioned here. I would think that if I could gain say 25hp that this would make a substantial difference in the way the old truck performs. This engine is a 54 230 truck engine and currently runs well.

One thought I have had is to begin by making the mods to the exhaust and intake systems and see if I get enough of a gain in power to go further with it.

 

I would appreciate any thoughts you may have on this.

Jeff

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Put a proper rebuilt 251 or best bet a 265... more than enough smooth power and torque.

I did years ago( 265) in my 1 ton .

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Bob;

Thanks for your input. Not sure what all would be involved with that swap besides moving the radiator forward? Would I have to lose the fluid drive?

Also I have never seen any of these larger displacement engine cores in the area.....I suppose they are out there but I have never come across one in the 4 years I have had the truck.

Jeff

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Yeah, I have a 251 in mine with a 3.0 rearend. I can go fast and have no trouble climbing the hills around my neck of the woods.

Mine has a 4 speed and I still don't use 1st unless I need to pull a stump.

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I don't know about that.  I use to have a 50 1/2 ton w/ fluid drive and I would drive it over Donner Summit 7000' elev. from where I live at the 2500' elev.

The old engine was tired but I had no trouble making this trip many times.

Edited by Reg Evans
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This is my opinion only....I don't care if you put a 500 inch motor in your truck, if you don't $hit can that parasitic fluidrive you will never gain the power you are seeking.....10 cents thrown in for inflation.

I have considered this. But there is a fair amount of work and expense involved to do just this conversion. And for potentially very little gain.

I think in the long run if I am going to put a lot of work into this I would be better off with a small V8 and a modern automatic. And maybe that is the best answer for me? There is a part of me that just wants to be able to get in it and go where I want without having to plan out the route.

.

Perhaps it is just wishful thinking to consider hopping up the engine that is in it? I was hoping to get by with bolt on stuff rather than fabrication etc..but then I would still be stuck with no synchro in 2nd. I guess I could live with that if I didn't have to tear the entire truck apart......but if I do too much and not get what I want out of it then I won't be a very happy camper.

 

Jeff

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I have considered this. But there is a fair amount of work and expense involved to do just this conversion. And for potentially very little gain.

I think in the long run if I am going to put a lot of work into this I would be better off with a small V8 and a modern automatic. And maybe that is the best answer for me? There is a part of me that just wants to be able to get in it and go where I want without having to plan out the route.

.

Perhaps it is just wishful thinking to consider hopping up the engine that is in it? I was hoping to get by with bolt on stuff rather than fabrication etc..but then I would still be stuck with no synchro in 2nd. I guess I could live with that if I didn't have to tear the entire truck apart......but if I do too much and not get what I want out of it then I won't be a very happy camper.

 

Jeff

I believe Ray Charles can see you should honestly re-evaluate your suitability to be an old-truck caretaker. No shame in that, as it's just not for everyone.

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Very little potential?....it feels like I have an engine and a half under my hood after deep sixing the fluid drive, as I've said in one of your other threads about this subject, now that you are done.....you seem reluctant/timid/apprehensive about changing anything. It's not an insult, ask fargos go far aka Fred about his swap to a standard 3 speed if you don't believe me.

These cars and trucks will always be give and take....never perfect, which seems to be what you are seaching for....

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I have considered this. But there is a fair amount of work and expense involved to do just this conversion. And for potentially very little gain.

I think in the long run if I am going to put a lot of work into this I would be better off with a small V8 and a modern automatic. And maybe that is the best answer for me? There is a part of me that just wants to be able to get in it and go where I want without having to plan out the route.

.

Perhaps it is just wishful thinking to consider hopping up the engine that is in it? I was hoping to get by with bolt on stuff rather than fabrication etc..but then I would still be stuck with no synchro in 2nd. I guess I could live with that if I didn't have to tear the entire truck apart......but if I do too much and not get what I want out of it then I won't be a very happy camper.

 

Jeff

Hi Jeff, yes economically going to a small V8 and auto trans may be the ticket, here what needs to be considered,

- engine /trans

-mounts  for the engine/trans

-drive shaft

-complete exhaust front to back

- rad and trans cooler, and lines

- gas pedal and cable/linkages

- shifter and throttle kick down cables

- 12 volt conversion

- gauges etc

 any other hidden items and expenses

Can you pull your current engine/trans and do the work to make a V8 go in? Or do you have to hire out for the job?

Keeping the 230,-shave head .050

-dual carbs/intake

-dual exhaust/split manifolds

- hotter cam profile

That should yield 30 plus horsepower for about what $1000, but it will be cool and unique, dead nuts reliable and still a flattie.

Just a shave head and split exhaust might give you 20 or so hp alone.

There is a guy on the HAMB, who has a 52 B2B, and it has an old 392, with a truck trans and an old poorly done V8 conversion, well ,he is talking about a frame swap, dakota front clip job, a 360 and auto trans, figures he needs to have a truck that goes along at 80 mph on the freeway.

Conversion to dry clutch,

-dry clutch bell housing

-move clutch housing cross member forward

- longer drive shaft ( the FD shaft worked as it extended slightly and the 3 spd tail shaft was longer than the m5 trans at least I think.)

-dry clutch trans, or  a conversion to A833 trans, but you obviously need that trans and the adapter plate, drive shaft etc.

- a T5 conversion, of which I know nothing about, so cannot suggest it one way or another.

Conversion to a torqueflite trans, but this requires an adapter plate, and mounts for the trans and the rear of the engine, not cheap, and not a bolt on swap that is super easy

Very little potential?....it feels like I have an engine and a half under my hood after deep sixing the fluid drive, as I've said in one of your other threads about this subject, now that you are done.....you seem reluctant/timid/apprehensive about changing anything. It's not an insult, ask fargos go far aka Fred about his swap to a standard 3 speed if you don't believe me.

These cars and trucks will always be give and take....never perfect, which seems to be what you are seaching for....

Hi Frankie, yes the old 47 Chrysler, not sure Jeff remembers my car or not, originally equipped with a 250, fluid drive and M5 semi-auto trans, it ended up with a 1950 Canadian Dodge 218 long block and dry clutch 3 spd trans, with a 3.73 rearend.

I can tell you compared to the 46-48 Chryslers with a 250 and fluid drive,my car with a 98 hp 218, was much quicker off the line and getting to speed, because of the dry clutch and 3.73 rearend.

I have drive a few Chryslers with fluid drive and M5 semi-auto trans, and they were real dogs off the line, have not drievn a car with fluid drive and 3 spd trans, but do not think they would be as fast as a dry clutch version.

I do believe in the 50s and 60s, a lot of the fluid drives were pulled out in favor of a dry clutch and 3 spd trans..

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post-107-0-98131200-1455317572_thumb.jpg

Edited by Fargos-Go-Far
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Hi Jeff, yes economically going to a small V8 and auto trans may be the ticket, here what needs to be considered,

 

There is a guy on the HAMB, who has a 52 B2B, and it has an old 392, with a truck trans and an old poorly done V8 conversion, well ,he is talking about a frame swap, dakota front clip job, a 360 and auto trans, figures he needs to have a truck that goes along at 80 mph on the freeway.

 

That guy is me (i think) and i'm just thinking about having a truck that keeps up in traffic here. 80mph is the going rate not to get run down between colorado springs and denver. I'm trying to decide if the stock suspension would be ok with the hemi after a disc brake conversion for the use it will see. Most of it will be city work, but i would like to be able to hit the highway here and there. Just considering my options really.

 

The old flattie has been gone from the truck since the 70's and the truck trans is gone (dad got rid of it). 

Edited by arominus
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That guy is me (i think) and i'm just thinking about having a truck that keeps up in traffic here. 80mph is the going rate not to get run down between colorado springs and denver. I'm trying to decide if the stock suspension would be ok with the hemi after a disc brake conversion for the use it will see. Most of it will be city work, but i would like to be able to hit the highway here and there. Just considering my options really.

 

The old flattie has been gone from the truck since the 70's and the truck trans is gone (dad got rid of it). 

Yup, read it this morning.

My point was to use your thread as a focal point, and in no way is a "put down". Just a reality vision for someone who needs and expects his old Dodge truck to keep up with modern day traffic.

I did not post on your thread, as there was a lot of advice already on there.

The stock suspension in preemo shape with disc brakes may surprise you, mine is pretty darn good, and although I do not drive at 80 mph, at 65 mph she drives and handles no problem.

I think you would also have no problem, new king pins, shocks, tie rod ends, tight steering box, and springs and shackles on good working order. In no way will be IFS, like the dakota front clip, it will be a truck, a little stiffer, but if in good condition will handle not bad.

I do not subscribe to what Gene mentioned these trucks are good for 50 mph in stock form, this is true perhaps with 4.11 or 4.56 gears, but even with my flathead 6, and 3.23 diff, can cruise nicely at 60-65mph, all day long.

Nice to see you here and good luck with your truck, as you can see, getting them to handle modern freeway traffic is a quest for many besides you.......

Edited by Fargos-Go-Far
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Yup, read it this morning.

My point was to use your thread as a focal point, and in no way is a "put down". Just a reality vision for someone who needs and expects his old Dodge truck to keep up with modern day traffic.

I did not post on your thread, as there was a lot of advice already on there.

The stock suspension in preemo shape with disc brakes may surprise you, mine is pretty darn good, and although I do not drive at 80 mph, at 65 mph she drives and handles no problem.

I think you would also have no problem, new king pins, shocks, tie rod ends, tight steering box, and springs and shackles on good working order. In no way will be IFS, like the dakota front clip, it will be a truck, a little stiffer, but if in good condition will handle not bad.

I do not subscribe to what Gene mentioned these trucks are good for 50 mph in stock form, this is true perhaps with 4.11 or 4.56 gears, but even with my flathead 6, and 3.23 diff, can cruise nicely at 60-65mph, all day long.

Nice to see you here and good luck with your truck, as you can see, getting them to handle modern freeway traffic is a quest for many besides you.......

 

No offense taken, i just noticed the post! I'm really interested in doing this in a way that keeps the fabrication down to a minimum, so thats why i'm soliciting opinions. If the stock setup will do me well, i have no problem going that way really. It keeps things simple. The springs are original as far as i know, but i'm sure they could be rebuilt. Any suggested sources for the stock parts so i can game this out a bit? rebuild kits for the steering box? I know i can get the disc conversion from rusty hope. 

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There are a few vendors on the disc brake conversion, RustyHope is 1 of them, and is a good product, he is a member on this forum too.

Uh springs and parts, tie rod ends, anything from Rock Auto to Oreillys, as well as the king pins, shocks etc.

Steering box kits, Andy Bernbaum, as well as leaf spring hanger parts, bushing etc. These springs once they are cleaned up, and the hangers can move are not bad at all. Lot of the guys remove the 2nd smallest spring too, this will lower the truck an inch or so too.

When you have time, do some searching on here for your topic desire, and you will find a lot on this topic. I say this before the "Forum Search Gestapos" jump all over you on it.

Hopefully more will chime in for answers on the leaf spring replacement vendors and any place you can get steering box rebuild kits from.....good luck

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I have considered this. But there is a fair amount of work and expense involved to do just this conversion. And for potentially very little gain.

I think in the long run if I am going to put a lot of work into this I would be better off with a small V8 and a modern automatic. And maybe that is the best answer for me? There is a part of me that just wants to be able to get in it and go where I want without having to plan out the route.

.

Perhaps it is just wishful thinking to consider hopping up the engine that is in it? I was hoping to get by with bolt on stuff rather than fabrication etc..but then I would still be stuck with no synchro in 2nd. I guess I could live with that if I didn't have to tear the entire truck apart......but if I do too much and not get what I want out of it then I won't be a very happy camper.

 

Jeff

I believe Ray Charles can see you should honestly re-evaluate your suitability to be an old-truck caretaker. No shame in that, as it's just not for everyone.

 

Well Ray.......I won't be replacing this truck with anything else so I guess your just stuck with me.

Some compression numbers would be helpful as I am trying to assess the condition of this engine that I revived rather than rebuilt. I am trying to gauge how far down on power it may be.

The bottom line is that it is my daily driver and needs to be able to keep up with the traffic and conditions I have to face.

 

Jeff

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Very little potential?....it feels like I have an engine and a half under my hood after deep sixing the fluid drive, as I've said in one of your other threads about this subject, now that you are done.....you seem reluctant/timid/apprehensive about changing anything. It's not an insult, ask fargos go far aka Fred about his swap to a standard 3 speed if you don't believe me.

These cars and trucks will always be give and take....never perfect, which seems to be what you are seaching for....

I am reluctant only because I don't have the money or time to go after this 2 or 3 times. Honestly I am not looking for perfection.....it just needs to safe and reliable in traffic. Right now I have to push it hard to be able to keep up and even then it falls short. That is not safe in my book.

 

Jeff

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Approximate compression should be about 110 for a 6.5 ratio engine and go up as the compression ratio is increased, according to the service manual. Shaving the head should raise the reading on the gauge. Usually, oil is added to a cylinder and a second set of readings taken to help determine the condition of the rings. A bore gauge reading of the cylinder at the top and bottom of the piston travel would help determine how much taper has worn into the cylinder walls and again help determine the condition of the engine. Getting and extra 25 hp out of the existing powerplant is doable. Converting it over to a more modern V6 or V8 with auto trans may be more feasible and get you closer to what you feel you need for your traffic. If having to make a change and making it only once, the V6 or V8 and auto is your surest bet.

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Thanks for your input Dave. I was above that sort of number last I checked but now that it has some miles on it I need to check again.

I would ideally like to stay with the flathead. It has been very reliable and has a lot of character. I am just trying to assess what work is going to be required to get the most out of it versus swapping in something else.

 

So far I have looked at changing the rear axle ratio to 3.73......$800 to $900 to have it done by local shops.

 

Headers and split exhaust.......probably $700 because I went with a SS system initially.

 

Dual carbs and new manifold ........Around $600

 

Shave the head .....about $100

 

T5 tranny swap......probably $4000 by the time I have all I need

 

Lose the Fluid drive.....? just a guess but probably $2000 or so by the time that is done

 

And I have not even added in the cost to rebuild the engine when required.

 

Jeff

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Thanks for your input Dave. I was above that sort of number last I checked but now that it has some miles on it I need to check again.

I would ideally like to stay with the flathead. It has been very reliable and has a lot of character. I am just trying to assess what work is going to be required to get the most out of it versus swapping in something else.

 

So far I have looked at changing the rear axle ratio to 3.73......$800 to $900 to have it done by local shops.

 

Headers and split exhaust.......probably $700 because I went with a SS system initially.

 

Dual carbs and new manifold ........Around $600

 

Shave the head .....about $100

 

T5 tranny swap......probably $4000 by the time I have all I need

 

Lose the Fluid drive.....? just a guess but probably $2000 or so by the time that is done

 

And I have not even added in the cost to rebuild the engine when required.

 

Jeff

You just need a source of a donor and you could ditch the fluid drive fairly cheaply. Maybe 48dodger has some parts in his field.

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Yes I can do a most of this myself. Pulling the fluid drive though does require a fair amount of donor parts.......plus the drive shaft will end up needing work I can't do myself. Need a different bell housing, a clutch, and probably a different transmission plus a different floor board. And then there is a pretty fair amount of work to do without access to a hoist. I think if I am going to go this route a T5 swap makes more sense.......I can't see doing all this and then not have full synchromesh.

 

Jeff

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Yes I can do a most of this myself. Pulling the fluid drive though does require a fair amount of donor parts.......plus the drive shaft will end up needing work I can't do myself. Need a different bell housing, a clutch, and probably a different transmission plus a different floor board. And then there is a pretty fair amount of work to do without access to a hoist. I think if I am going to go this route a T5 swap makes more sense.......I can't see doing all this and then not have full synchromesh.

 

Jeff

You just need the driveshaft from the same donor as the rest of the stuff. Trans I believe is the same except input shaft.

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