One reason for going trunks over cross heads is RPM. Supposedly you can only run cross heads to 2500 but trunks are ok to 2800. I think in automotive you could even go a bit higher

 

Hmm, I suppose the crosshead pistons being two piece deals could be a limiting factor.

That said... Shafer has posted that he has ran his trunk pistons in several engines up around 5500rpm with modified valve trains. I don't plan on doing that but... if I'm going to rebuild or replace parts I may as well replace them with parts that can handle anything I ever throw at it.

 

Cross head pistons are good for 3100rpm. If you've ever felt a trunk piston in one hand and a crosshead in the other, they are vastly different in weight. Early cross head pistons had issues with the crown delaminating from the rest of the piston. The current revision has added ribs on the underside of the piston dome. I have the governor on my 4-53T Silver set at 2990...no issues at all when it was on the dyno. It sounded awesome at near 3000rpm. If you want long service life from your 53, build it up as a silver engine with cross head pistons. They are proven to deliver twice the service life of trunk type pistons in medium and heavy duty applications. You can run trunk pistons at incredibly high rpm for a short while, but you better have deep pockets and the ambition to rebuild your engine after every other run. The crankshaft simply cannot handle that much strain. Just use a different engine if you want to push it more than twice its designed capacity. If you are planning to run your engine above 3000rpm down the road, you are simply asking for trouble. Gear your vehicle so that you are cruising around 1900rpm. That gives you a thousand rpms to accelerate to pass or catch the next gear.

Chris

 

Cross head pistons are good for 3100rpm. If you've ever felt a trunk piston in one hand and a crosshead in the other, they are vastly different in weight. Early cross head pistons had issues with the crown delaminating from the rest of the piston. The current revision has added ribs on the underside of the piston dome. I have the governor on my 4-53T Silver set at 2990...no issues at all when it was on the dyno. It sounded awesome at near 3000rpm. If you want long service life from your 53, build it up as a silver engine with cross head pistons. They are proven to deliver twice the service life of trunk type pistons in medium and heavy duty applications.

Well I stand corrected. I have read a few times cross heads were the reason the 53Ts were normally governed to 2500 while the N/As were 2800 but it's clearly not the whole story... Either way, it seems trunks are more suited to higher speeds, probably because of the weight you talk about. And are there really that many heavy or even medium duty applications 53s (or even 71s and 92s now) are used in any more outside of the military? I doubt cb88 would describe his project as heavy duty?

 

Seems like crosshead pistons are the way to go then in my use case..... I'll probably try and list the specific parts I intend to rebuild with once I make note of the parts that are on my engine I intend to reuse (just the head block and accessories I guess)

Would the head need to be machined to use crosshead pistons or should I be fine as long as I rebuild it with the same valves it has now, with silver liners and ports?

 

The block does not have to be modified in any way to run a silver liner or crosshead piston. If you are rebuilding the cylinder head, I would recommend having the head machined flat, and at the least new guides/seals installed. Going all of the way on the head really isnt that expensive when you only have three cylinders to deal with. Its just 12 valves, 12 guides, 12 seals, 12 valve seats, 12 valve springs and 3 injector bushings and o-ring sets. Because you want to use cross head pistons for longevity reasons, you will either have to buy a silver camshaft with short port 0.74" liners, OR use your "green" camshaft with 0.84" tall port liners. The liner port height matches the camshaft. It is not advisable to run a short port liner with a green cam. You can get away with using your current balance shaft and camshaft pulleys if you use a hybrid set of balance weights on the cam/balance shaft gears. You may need to grind your flywheel housing for clearance... Alot of this is covered in my truck thread. I spent a week at Leid Diesel turning my green 4-53T into a Silver 4-53T. You might want to read through that, and then give the folks at Leid a call to see about pricing. Because you have an aluminum block, you may have to have the main's checked, as the aluminum blocks were not as rigid as the cast iron blocks. It would be no fun rebuilding your engine only to find out it has to come apart to be line bored. They will also be able to tell you if any of the oil passages in the block need to be enlarged.

Chris

 

Well I'm about to head outside and do some initial cleanup on the engine (remove some traces of it being hooked to a sawmill)

I'm leaning toward a T56 transmission but am concerned about the first gear ratio... I know some people have said the low gear on some transmissions was almost useless due to being way too low. Anyway... I whipped up an excel file that calculates transmission ratios and makes a graph of RPM vs MPH since one I did find only did it for a 4 speed and wasn't easy to extend.

Also with the T56 there is the matter of hydro vs manual clutch.

I've put the ratios in for T56 wide and close ratio magnum transmissions. You can also change the rear end ratio, and tire diameter. I made this using Gnumeric so I hope it works fine for those using MS Excel but no guarantees if it doesn't work I'll fix it later, I think it will work fine though perhaps the graph might not. Here is the link from my homepage It's licensed CC-BY so just keep my copyright on it and use however you want. (woops I'll just post the images till I hit 10 posts!)

Here is the T56 close graph

 

and the T56 close graph

 

And here is the excel file for the interested. You're welcome to browse my homepage just be warned it's nerdy but completely safe for work ;-) and hosted on the computer equivalent of an 353N (Its a quite loud Sun Microsystems T2000 which I have dubbed leafblower for obvious reasons) http://www.gh0stwriter.net/stuff/TransmissionCalc_byChaseRayfield.xls

 

Do you know of anyone running a T56? I think it might be a little light on torque capacity.

Ed

 

The T56 magnum is rated for 700lb/ft and my 353 is probably not going to break even half that. A plain T56 probably would be a bit wimpy though... you're right about that.

No I don't know anyone... but it also always seems that everyone does thier own thing this these so what else is new

 

Is wheel diameter in the equation? Seems like with either transmission your gearing is way too fast. With a 3-53, you will probably need 1900-2000rpm to get down the road comfortably at 65mph, not 1400....

Give this calculator a shot. You can input transmission ratio's engine speed, axle gearing and tire size... (scroll down to "Find MPH")
http://www.onlineconversion.com/bigger_tires.htm

Once you get the sweet spot achieved, (by tweaking the axle and tire size to the transmission) you will have a pretty good idea how your rig will turn out. Wasnt someone on here putting an Eaton FSO-6406 6 speed overdrive behind a 4-53T? Short of a big heavy roadranger, or a Spicer ESO66-7B that would probably be another decent alternative.

Chris

 

Yes, check out my excel sheet... wheel diameter, axle ratio, and transmission ratios are used and it will all update dynamically if you change these values and it comes up with the same value as the calculator you suggested (I've seen that one as well). I also checked my numbers against this one http://spicerparts.com/calculators/transmission-ratio-rpm-calculator.

The calculation is actually quite straightforward, (RPM*60min)*(wheel diameter in * PI)/(12in*5280ft)/(axle ratio*trans ratio) which gives you MPH per RPM.

I should probably add in transfer case ratios for those that care but I don't at the moment I think. If you check out the spreadsheets 5th gear doesn't look too bad at 65 and I should be able to accelerate in 4th 55@2500rpm and 65@2800.

6th would put me around 70@1500rpm. I suppose I should hunt down those hp/vs RPM curves I think they are posted here somewhere. Then figure out how many HP it takes to maintain speed in a K5, as well as maintain speed on mild grades around here. I haven't looked into it yet much but if you check here it takes about 25-30Hp to maintain speed on level ground in a blazer@55 MPH http://www.chevyk5blazer.com/forums...r.com/forums/showthread.php?17898-MisFit-Blazer-1988-K5-Blazer-efficiency-build

http://www.wallaceracing.com/Calculate HP For Speed.php

using that calculator and the following values I need 35Hp@55 Coefficient of drag = 0.6 (this is generous) , Frontal area = 35sq-ft, 6000Lb and 55mph. at 75mph I would need 76Hp.... which would mean I would need to be around 2600Rpm to mainain that speed without a turbo. But I do intend to add a turbo later on which probably will mean I will be able to maintain these speeds just fine at lower RPMs as long as I don't go with a huge turbo that only spools up at 2500rpm heh. I realize this is not accounting for drag in the driveline... but I'm building this just to get down the road initially and make it more driveable with a turbo later. Basically without the turbo It's like im driving a 4speed due to lack of enough Hp at lower RPMs to even use the higher gears, except I don't have quite as wide ratios due to the useless (for road driving) granny gear that anyone with 4 speed would have to deal with.

 

I did not open your excel file yet, I just looked at the graphs. Your math in the last paragraph is almost spot on with the 1986 (wheel Hp) test Dan R. sent me of his 3500 GMC with a 4-53N, Spicer 3152A transmission, and C50 injectors (136 gross horsepower). At 75mph, his vehicle required 74.6 hp to move at 0.00% grade. 80.5hp @ 0.5%grade, 86.5hp @ 1.0% grade, 98.5hp @ 2% grade, 110.5hp @ 3% grade, and 146.4hp @ 6% grade,... 10% grade was 173.2hp @ 70mph. The data report shows that his truck weighed 6000lbs. Very similar to what you plan, however with a different a slightly different drive train.

Count on a mechanical fan with a viscous clutch to pull 8-10 horsepower, an air compressor to pull 2-5 horsepower, 1 hp for power steering pump, 1 hp for alternator, etc. An overall drive ratio of 2.90, and ~1900rpm @ 65mph is pretty much the ideal sweet spot for the 53's.

Chris

 

That makes a good case for electric radiator fan...which I've seen people suggest before. I'm not aware that the 53 series needs a compressor for anything other than an air starter? Which would be cool... but pretty unnecessary and potentially a headache. At least the k5 or M1009 is a smaller truck certainly not as heavy as a k3500

Running an AC would be about 3-4Hp probably...

Looks like the M1009@5200lbs is a good 1000-1500lb heavier than a K5 http://ck5.com/forums/resources/k5-blazer-specifications-1980-1991.8/

The M1009 has 3/4 ton axles .... not sure it's worth it though.

 

air is primarily for brakes, but can also power accessories like tranny range change/splitter, horn, PTO switches, clutch assistance, throttle. Yes a fan takes power, but it's not wasted - if you don't need that much cooling go to a smaller fan. No electric fan can ever come close to giving the cooling power of a full size mechanical fan. But then maybe you don't need that much cooling, I'm just used to obsessing over cooling due to our climate, the thought of downgrading cooling capacity is hard for me to imagine! 53 series heads already have cracking issues unless you've got a late "dog bone" type head too

 

Yeah I forgot about that... my VW rabbit has a compressor for this reason as well. though I don't think it is a high pressure compressor just enough to pressurize the crankcase and master cylinder.

 

first time I've ever heard of factory air brakes on a car, certainly on a VW! But I'm no expert so will take it from you... Also a viscous fan would only take 8-10hp when engaged, it would take almost nothing when not engaged (as in when the engine isn't on a long hot pull)

 

The VW Rabbit doesn't have a compressor, it has a vacuum pump for the power brakes. Earlier Ford diesels had this also. Also note: switching from trunk to crosshead pistons requires different connecting rods as well as different balance weight/pulleys for the front of the cam/balance shafts as well as additional weights for the timing gears.
David

 

Correct, I had a brain fart mine has the crappy little diaphragm vacuum pump on it. Compressor/Vac Pump ... Potato/Pohtahtoh

Anywho, I've uploaded a video of my engine here https://youtu.be/KJtModbxV5g

The rockers have a bit of rust on em, but I think it looks ok otherwise in my unprofessional opinion. And I need to fix the starter... I'm not 100% sure there isn't a reason it is that way (if it was getting stuck engaged or something of that nature)

The breather filter is completely full of sawdust.. and I vacuumed about a quart of oil/sawdust off of the engine's various crevices. Need a new valve gasket... as well as the old one was half rotted away.

 

So, the Masco MA-10882 starter looks like a good bet but before I drop all that money on one of those are there any alternatives that are as good but less expensive?

The 30MT I really don't feel like repairing... or running at 12V with less output. I'm not too keen on putting another direct drive on either. So that leaves gear reduction starters...

Also does anyone know of the quality of this oil? https://www.amazon.com/Miles-Heavy-.../ref=sr_1_fkmr0_4?ie=UTF8&qid=1481263532&sr=8-4-fkmr0&keywords=40+cf2+oil+10gal

 

West Marine has a location in Charlotte, North Carolina. Chevron Delo 100 SAE40 can be ordered. It is $29 a gallon by me. I would not take any chances running some questionable oil in your two cycle diesel. There are a couple good alternatives out there. I personally use Chevron HDMO 40 as it meets all of Detroit Diesels requirements. Some folks run Shell Rotella T-1 SAE40, it falls short of the sulfated ash requirement by a percent or so, but I would at least use a name brand quality oil over the cheapest oil you can find. Miles Petroleum is literally down the street from where I live. They are not a refinery, they are a distributor and primarily rebrand other generic oils for sale at big box stores under other names. Although it would be nice to support a local business, I choose to buy my oil elsewhere.

What is wrong with your Delco 30MT Starter? When properly cleaned and lubricated they last forever and then some. You can do basic cleaning of the starter nose, pinion and shaft at home. If that does not work, move on to testing the starter solenoid. You can get new solenoids for less than $50. Without knowing more information it is hard for us to help diagnose your problems. Who knows, it could be something as simple as increasing the gauge of the wire, or cleaning electrical contacts.

Chris

 

The 30MT is heavy, 24V (though it could be swapped and half it's output) and also not in good condition (broken solenoid as well as missing parts so I'm not sure if perhaps there are other things wrong with it as well).

$30 a gallon is quite expensive!

Edit: I pulled the starter off yesterday... there were only 2 of 3 bolts in it so it is just as well that I did. Also, I unbolted the sm420 but it didn't "slide right off" so I expect it will require a bit more elbow grease perhaps monday evening.

 

So I was able to get my starter (the Masco model... which I recieved promptly after ordering as they are just down in SC and I'm in NC), it says to turn the vents on the starter down (I guess to drain water if it gets wet but that is unlikely in my application..... but I wasn't able to mount it with them down only sort of out to the side. Actually it looks to me like this starter was designed on mount exactly upside down from what it is on the gama goat bell housing. If anyone knows how to fix that let me know otherwise it will probably stay that way.

Also, after I got it to turn over it smoked a little and fired... and ran for s 3-5 seconds before dieing I suspect fuel isn't getting through the filter. I had the valve cover off I did see that oil is getting pumped up to the head as it was dry before starting and some oil was visible after it had ran a few seconds. I haven't changed the oil yet.. but have a 5gal pail and intend to do that as soon as I get it up on a block or mount etc.... new oil filter, air filter, and fuel filters. I'm hoping to get it running before I head back to work in January.

Actually I'm fairly impressed with the starter, it was about 40 degrees outside today and it turned it over fine with the battery out of my VW rabbit diesel.

 

Alright so the thermostat housing has a hole in the top of it shooting water about a foot in the air... what gives?

Ahem, I checked the manual and it doesn't really say anything specific bout this. It appears that there should be a fitting here that is broken off perhaps but I am not sure. Perhaps for a return line to the radiator so air gets purged? I have temporarily plugged this hole so I don't loose all my coolant but I intend to fix this sooner than later.

Running for a bit to circulate some coolant I added to make sure it doesn't freeze in a few days:
https://youtu.be/1-m9qpruyO8

 

It should have a bleeder fitting in the top of the housing for burping the cooling system when its filled. It'll be under water pump pressure when it's running. Checked out your video but couldn't really see what was there. Seems like it runs pretty good. TC.

 

https://www.youtube.com/watch?v=JVBknaNEc0o

You can clearly see the fitting in this guys video ... and if that is what it is supposed to look like I'll have to get an easy out or something of that nature and fix it... I think I saw in someone else's video they had it plugged into another bleeder fitting from the other end of the block instead of running it to the coolant resevoir!