Re: K30 Downgrade to Cummins Project
 

Ya I follow along and check in at least once a day but just realized I haven't posted on my thread in almost a year!! My bad. I'll try to get a update this weekend.

Re: K30 Downgrade to Cummins Project
 

I found a new 3rd gen Cummins genuine tensioner for $75 so went with that.

An IC 1st gen hub would probably work better but they are hard to find. Do you have one? I wish I had one to at least borrow to look at/measure. Unfortunately I sold both 92 dodge w250's i had awhile back. I may just fab one up like you say.

Got your email. now I see you emailed me back late Jan, not sure why i didn't get it or see it before!

Sounds good! You have a great project there and we'd like to see more of it.


I took the running boards off awhile back but forgot to post a pic. I think it looks better

Re: K30 Downgrade to Cummins Project
 

I started reading your build a couple weeks ago, I like it.

Looks like your working out the ac compressor mount. I bought the Cummins high mount freighliner parts and modified the alternator bracket so I could use the dodge denso unit. When I was doing the changeover I felt like I could have modified the low mount ac bracket like you are working on.
Looks like you will have to change water necks for belt clearance.
When I put the ac on mine I tried the tensioner up high like you have yours sitting (4bt style) I hade very little belt clearance and the belt length had to be spot on, took a bunch of fitting and belt searches and in the end the tensioner did not tension the ac compressor enough which caused it to chip from belt skipping and when that happens The tensioner has wild adjustment fluctuations. It was jumping crazy back and forth trying to keep tension.

I read it’s best to have the tensioner last in-line and that’s what I did, I put it down by the frame rail, fixed the problem.

For belt length I cut my old dodge belt then used it to wrap and mark needed belt length, laid it out flat and measured the length then found that length online in the gates or dayco online catalog. Belts are $50 or so local but I found the ones I needed on rockauto, amazon and eBay for about $20 or less.
There are plenty of 8rib belts in the length you need...that had me worried too.

For your tach, you can get a tach signal from the 2nd gen crank sensor, I wrote up how to do it, just set your aftermarket gas tach to 4 cyl mode and it will read correctly (2 pulse per revolution) which you get from the 2nd gen sensor.

You have probably already looked it up but a 1st gen fan hub will move the fan up and center I believe, it also gives you .75” or so of more fan to radiator clearance, the pulley is different from 2ng gen so you need it with the fan hub.

Re: K30 Downgrade to Cummins Project
 

I will share some A/C things I learned too...
The sanden sd715 compressors, I think all have the same bolt pattern and the variances are compressor clutch style and clutch groove centerline and back head style.
The wires vary and have or do not have diodes, change out as needed.

I bought a new compressor from acparts.com for about $130, it was a random compressor that had the proper 8rib centerline and a head configuration I thought would work and it did. I searched by price then researched attributes of compressor number on the sanden website.

As far as your home made bracket...if you can somehow duplicate the lower compressor bolt centerline to above the waterneck it will all line up when installed. I think you could fasten the existing bracket to a bench, find or attach a measuring point and modify away.
Maybe you Could make a flat plate for the ac compressor that mounts to the lower bolt holes with spacers and hole that clears the waterneck? If so you could lay out the pattern on flat plate then bolt it to the dodge cast iron bracket.
You can ballpark the lower alternator mount and adjust with shims or spacers to get the centerline right.

I made my own lines using aeroquip ez-clip fittings and line, these lines and fittings are expensive in kit form or new but can be found on ebay super cheap. They “crimp” using cv joint clamp type pliers, aeroquip sells the crimpers for $120 or so.
I used Oetiker side jaw pincer pliers for single ear clamps. I used the single ear clamps on my fuel, vacuum and pressure lines too, eliminating gear driven hose clamps which I hate.
Compatable fittings to aeroquip are available under weatherhead and red dot brand names too (eBay and other sites), they are all identical.
There are a limited number of ac line sizes and fitting types, fitting charts are online, just match up to the parts you have like condenser, evaporator and compressor head or manifold,
Nice looking lines, very heavy duty and easy to assemble and crimp at home.

I have some pictures of the ac stuff in my crew cab preview thread.

Re: K30 Downgrade to Cummins Project
 

Jud, the only one I have is on my Longhorn. I'll dig through my stash and see what else I have. I used to have a couple weird ones off of 4BT's.

Re: K30 Downgrade to Cummins Project
 

Thanks Randy for the good info. You;re right about the tensioner placement. I have redesigned it to have an idler pulley rigidly mounted by the water neck and the tensioner down by the frame rail. Below is kind of a mockup showing where things will be. I think there will still be enough wrap angle on the crank pulley, that is my only concern at this point.

Also shown is a pic of my machined DOM and steel plate solution that will do the same thing as the 1st gen intercooled fan hub mount.

Yep, I put a straightedge from another pulley on the engine and measured off that to set the distance for offset. My bracket ties to the engine in two spots and the bolt hole on the lower waterneck that the tensioner used to go into. I think I can do an angle iron bracket off the old compressor block mount holes for the belt tensioner.

No worries, I want with the DOM and plate fabrication. The fan is now about 2 inches higher and 1.25" towards passenger side compared to than the 2nd gen position. Its weird the passenger side shift works better with the 2nd gen fan shroud, rad and radiator hose setup. I don't know if my hoses are longer and need to be cut to length or what, but I expected the left right with all 2nd gen stuff to work best with the 2nd gen fan position!

Re: K30 Downgrade to Cummins Project
 

THis pic flipping is maddening. Even if i preflip it, anticipating a flip, it still effs it up GRRRRR.

Re: K30 Downgrade to Cummins Project
 

WHat are you using to take the pictures?

Re: K30 Downgrade to Cummins Project
 

iphone then putting them on my laptop since i can't log into the forum on my iphone. Is there a tech support area on the forum?

EDIT: found this https://www.67-72chevytrucks.com/vbo...d.php?t=743225

Re: K30 Downgrade to Cummins Project
 

I will add that if you post directly to the forum using iPad or iPhone, horizontal works.
If you upload a photo taken with iPad or iPhone it doesn’t matter how the picture was originally taken it will be sideways.
If you edit a picture previously taken to be sideways then post, you will get random results. If using iPad or iPhone the best way is take the pic horizontal via manage attachments.

Re: K30 Downgrade to Cummins Project
 

How do you login from iphone and ipad? I pull up the site and it never allow the login to complete. Is Safari not compatible?

Re: K30 Downgrade to Cummins Project
 

I haven’t had a problem with safari or logging in. I just tested logging out and back in. It was fine

Re: K30 Downgrade to Cummins Project
 

Im using safari on my iPhone too, I actually never logged out since joining. If and when you get it logged in, if you forget to take a picture “correctly” then you can always open the picture on your phone and screenshot it with the phone in the right direction. Then the screenshot will post correctly

Re: K30 Downgrade to Cummins Project
 

Still can't log in on my iphone. Do you have to log out on other devices such as PC before the site will let you login from a phone?

Anyways lets try this again from my PC. I think I have the pulleys and brackets all figured out. Here are some pics. I think the belt wrap and clearnances all look good. Made a bracket for the smooth idler pulley and found a small ribbed idler. Its a new Dayco for a toyota tundra application. Its on the 3rd gen dodge tensioner. Oreilly's had an 8 rib x 76" belt that should do the trick, thats what I mocked up to be by cutting down the longer 2nd gen belt.

Been getting a ton of snow here lately (40 inches here for the month so far) so the old K20 is getting a workout on my long driveway. Its good to have granny low.

Made some good progress on tranny mount xmember.

Also as you can see I need to clean up the air cleaner, look how rusty it looks. Maybe if i got one from a squarebody it would fit better?









Kinda joking here but also thinking it would be funny to some how rig it up to be functional. Open the hood and just tell people its an HD 292 engine :lol:

Re: K30 Downgrade to Cummins Project
 

Looks like a good solution to your fan problem, I was lucky enough to use a 1st gen setup. Like the idea on the factory air cleaner, but function would be horrible. Remember these things use a ton of air and that’s what keeps it from being Smokey and hot. Just thought I’d show you my setup, eBay pieces together for $55 total and it actually has a fresh air supply under it thanks to a rotted core support

Re: K30 Downgrade to Cummins Project
 

Has anyone used one of these kits? How hard is it to swap the gear onto the Chevy pump? I'm fighting getting enough clearance by the motor mount on the driver side with the vacuum pump mounted power steering pump lines touching the mount. Also I have zero need for the vacuum pump unless I use stock squarebody AC components. Even those I'm not sure if they need vacuum or not.

https://www.ebay.com/itm/Saginaw-sty...frcectupt=true

haha, yeah its probably not practical but perhaps I could use the bigger later squarebody snorkel and air cleaner setup that runs towards pass fender :) Maybe it will just be for decoration or to do some other function, like house a under hood work light or wiper fluid or something

Re: K30 Downgrade to Cummins Project
 

I have zero experience with that setup so i can’t say, on my 70 I kept it as to actuate the vacuum doors for the HVAC and the heater control valve. I was able to get away with a tiny notch on my 1st gen dodge mounts but perhaps in your case you could use a stock mid 80s up gm metric line. I’m using the cummins pump with 88-99 lines as they all seem to use the 18mm and 16mm thread connections.

Re: K30 Downgrade to Cummins Project
 

Here is the crossmember so far. Got it cut and tacked together last night. I looked into modifying the TH400 Xmember but it always hung lower than I liked and it would have been harder to modify than building this out of 2x2 square tubing, some plate and 3x3x1/4 angle iron. I;ve got new stock rubber mounts for the Getrag application just sitting on there.

Re: K30 Downgrade to Cummins Project
 

Looks Awesome!!!

Re: K30 Downgrade to Cummins Project
 

Trans Xmember fitting complete. May put some other angle braces on to tie to the side of the frame as well, we'll see. The angle iron that mounts to the frame is 1/4" thick so its pretty strong actually.

Also it doesn't look like progress but it is, got the engine and driveline out for the final frame and crossmember welding and driveline rebuild/resealing. I think I'll make the engine xmember center piece bolt in in case I need to touch the oil pan at some point.

Re: K30 Downgrade to Cummins Project
 

The stock 1st gen dodge downpipe wont clear the firewall. Its a pretty large radius. Does anyone know of a good option? My HX35 outlet is only 4.25" from the firewall. Good thing is the industrial manifold keeps it down a bit.

Will these options fit?
https://www.dieselconversion.com/exh...l#!prettyPhoto

https://www.summitracing.com/parts/d...saAmUJEALw_wcB

Re: K30 Downgrade to Cummins Project
 

All I did on mine was use a piece of mandrel 3.5” pipe and cut it down so part of the bend is actually where I cut it. Then welded it to my flange. Cutting I the bend will give you a little of an oval but easily rounded with a hammer.

Re: K30 Downgrade to Cummins Project
 

That looks like a good solution. Is your exhuast 3.5 inch all the way out the back?

Re: K30 Downgrade to Cummins Project
 

No, inches past the frame rail it goes to 4” all the way back. My theory was the outlet in the turbo is smaller than 4” so going this route isn’t a bottle neck. Then as the temp cools the velocity of the gasses slows so I stepped it to 4” to keep back pressure down, with 5x12s and the he351 I’ve yet to get over 1100 degrees trying to make it run hot

Re: K30 Downgrade to Cummins Project
 

adding a couple ports to the G360 to accommodate the widely recommended 1 to 1.5 qt overfill procedure.

1st pic is of where the fluid comes up with 1qt overfill relative to right PTO cover bolts. The 2nd holes from the top would be a good check for 1qt over.

Pic of the ruler shows how the 1.5qt overfill is almost 5.25 from the top flange of the main case. The 1.5 qt overfill lines up pretty well with the top PTO cover bolt on the left side of case. Its important to note that the bolt holes on the right side PTO cover are higher than the left side PTO cover.

Regardless of being able to use left PTO cover bolt hole, I still added a 3/8" NPT hole on the left side of my case to put a pipe plug in to make it easier to check the level with a finger or wire. The 3/8" bolt hole is a little small for an easy check.

Also shown is top fill I added which should be easily accessible under the t case shifter boot inside the cab.