1988 Chevy Blazer K5 Cummins 6bt

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rube bonet

Discussion Starter · Oct 1, 2010 (Edited)

I have been working on this project for a customer of mine for some time, I've finally got enough progress to share. I decided to share it here because of the info I have gained by lurking around this site has saved me quite a bit of time. I am also in the process of putting a 4bt into an fj40 landcruiser for a friend of mine, and have been gathering parts for my own 6bt powered fj60 cruiser wagon, so I have definitely spent some time here. I have owned a couple cummins powered trucks, and done many engine conversions, but these three are my first cummins conversions.

PROJECT OVERVIEW:
1988 blazer, repowered with 1995 12 valve out of dodge 1ton, 47rh trans- to be rebuilt by fred swanson, and 205 transfercase. Axles are dana 60 front, 14 bolt rear, w/ ARBs in both. Suspension will be custom leaves by Alcan, sitting low on 35s. The Blazer will be built as a light duty tow rig/ camping truck/ "reason to hang out in the shop and drink beer with the dog instead of honey-do-list"

This is the blazer in question:

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rube bonet

Discussion Starter · #2 · Oct 1, 2010 (Edited)

3

First order of business was reinforcing existing frame and the many problem areas that exist on these frames- even before putting a cummins into it. To be truthful, the first order of business was getting a new frame to start with, the existing one was junk.
I set the bare frame on level stands, and was amused to find the frame was so flexible i could pick one corner up about 6 inches before it would pull any of the other corners up...

I started by cutting out the motor mounts and front crossmembers, replaced the front with 2x5 .188 rec between the body mounts, then plated in steering box area. (this whole area will get some more gussets, but that will have to wait until later)

(sorry some of the pics are out of chronological order)

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rube bonet

Discussion Starter · #3 · Oct 1, 2010 (Edited)

3

Next step was to add some beef to frame to support torque and weight of cummins. I boxed the frame rails with 10 ga CR from front crossmember to past where trans crossmember/ skidplates will rest. Frame should still be flexible to some degree, but alot more resistant to cracking.

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rube bonet

Discussion Starter · #4 · Oct 1, 2010 (Edited)

3

Area of the frame where the motor mounts go was left unplated, so motor mounts could go directly to inner frame. Frame boxing will then meet motor mounts, and be completely boxed in after motor is mounted final. Rear upper shock mounts were also plated/reinforced.

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rube bonet

Discussion Starter · #5 · Oct 1, 2010 (Edited)

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Motor/ tranny / t case were ready to be positioned-- it is a tight fit, especially with no bodylift/ minimal suspension lift. Reading on here, I discovered most people notch out the frame to clear the AC compressor, which I didn't feel was the best solution, at least not if there was another option available. I've spent alot of time repairing frames on these chevys- esp the 1/2 tons, so I really didn't want to weaken the limp noodle frame any more than I had to.

After a lot of time on here researching... I started ordering parts. Turns out ford f-800s and freightliners have narrow frame rails, and used 6bts, so I thought at least that was a start. I ordered the brackets, about 1/2 of which actually worked. Main cast bracket was fine, but upper alternator bracket interfered with dodge water outlet, and the water inlet wouldn't work either, and the tensioner bracket was still close to the frame. On the plus side, new mt use 22si alternator, and it all still fits under the hood.

So.... I fabbed up new upper alt bracket to work w dodge outlet, new water inlet to match radiator (1.75) and allow a hose to work, and a slightly different tensioner bracket to clear the frame.

All in all, definitely more time consuming and expensive, but well worth the end result IMHO.

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rube bonet

Discussion Starter · #6 · Oct 1, 2010 (Edited)

3

Getting the compressor to clear the frame meant I could do final motor positioning. It is tight to bellhousing, tight to firewall and tight to the radiator, but actually a pretty good fit. 1" room from fan clutch to radiator, 1.5-2 between head and firewall, and tight (.375) to the bellhousing in two spots, that will be remedied with BFH lovingly applied after motor is pulled for final welding.

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rube bonet

Discussion Starter · #7 · Oct 1, 2010 (Edited)

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Finally, I could start cutting out the motor mount plates, designed to use the stock 1995 isolators. Plates will weld directly to inside of frame "c", with a removal crossmember between the two to allow easier motor removal, and to make it possible to pull the oil pan in the truck.

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greguw

· #8 · Oct 1, 2010

Looks great buddy , my front frame looks similar to yours but I choose to continue the boxing and channeling the whole frame .
Planning on running a track bar or did you retain the original sway bar ? I went with the Deaver springs and moved my rear mount under the front body mount .

cRiPpLe_rOoStEr

· #9 · Oct 1, 2010

rube bonet said:
The Blazer will be built as a light duty tow rig/ camping truck/ "reason to hang out in the shop and drink beer with the dog instead of honey-do-list"

cool... i like the idea about the camping truck...

rube bonet

Discussion Starter · #10 · Oct 1, 2010

greguw said:
Looks great buddy , my front frame looks similar to yours but I choose to continue the boxing and channeling the whole frame .
Planning on running a track bar or did you retain the original sway bar ? I went with the Deaver springs and moved my rear mount under the front body mount .

Will most likely put the stock sway bar, will make final judgement after springs are in. I've used the long deavers in the past on prerunner/rockcrawlers projects, alcan was customers choice. Either spring really would have worked great, even overkill for his application.

rube bonet

Discussion Starter · #11 · Oct 1, 2010

cRiPpLe_rOoStEr said:
cool... i like the idea about the camping truck...

I really liked the "reason to hang out in the shop, drink beer with the dog and avoid honey do list" idea, that is almost a direct quote from the blazers owner,.

:beer:

cRiPpLe_rOoStEr

· #12 · Oct 1, 2010

rube bonet said:
I really liked the "reason to hang out in the shop, drink beer with the dog and avoid honey do list" idea, that is almost a direct quote from the blazers owner,. :beer:

sure...

:beer::beer::beer:

btw what are you intending to do with the interior trim? for a camping rig washable materials would be preferrable...

coreystroke02

· #13 · Oct 2, 2010

Nice build! Keep us updated.

rube bonet

Discussion Starter · #14 · Oct 6, 2010

cRiPpLe_rOoStEr said:
sure...

:beer::beer::beer:

btw what are you intending to do with the interior trim? for a camping rig washable materials would be preferrable...

Interior is still up in the air, I didn't want anything that was going to get wet, or at least wet and non removeable. Basically, i would like it so the inside could be hosed out. Do you have any experience with lizardskin (or something similar)? I was wondering how effective it was at noise reduction, I would really like the interior to be quiet...relatively speaking. What are most guys doing for firewall insulation/noise reduction?

rube bonet

Discussion Starter · #15 · Oct 6, 2010

4

I will try to get this thread up to date...

Motor mounts fill in inner C completely. Frame boxing will extend to motor mounts & between plates, after motor is pulled and final welding done to all.

Starter is a little tight, but still goes in and out easy enough

Crossmember was built out of .250 dom tube. .25 plate, and 10 ga plate

It actually tucks up slightly higher than the factory drivetrain did, dodge 205 is clocked farther up on the adapter than chey 205, or the 208 that was in this truck. Tcase skidplate is removeable, factory dodge transmission mount was used, trying to keep vibes to a minimum

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rube bonet

Discussion Starter · #16 · Oct 6, 2010

3

Mount on lower side of motor mount crossmember was for an oil pan, trans pan skidplate made out of 3/16

Front diff clearance to oil pan looked really tight, especially with large dia 1350 driveshaft yoke in there, but I flexed it up with forklift, driveshaft and yoke never came within an 1" (even with no bumpstops currently, and WORN out rancho 2 1/2 1/2 ton springs

Oil pan skid

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rube bonet

Discussion Starter · #17 · Oct 6, 2010 (Edited)

3

Bracket was made for tcase shifter to bolt to 47rh. Shifter pivot uses two bushings i machined out of delrin, 3/8 rod ends threaded into a piece of 6061 attached to original dodge 205 shift rail bracket

I bent a piece of 3/4 dom to come out thru factory hole, it still need to be cut to length and have knob added. I should be able to use factory knob and boot for 1991 chevy 1 ton- but they seem to be discontinued?

Does anyone know where I could source one? It is too new for the reproduction guys, and floor is different pattern than earlier stuff. I could always use a different boot, but part of the goal of this project is to make it look "factory"

Which brings us to today, cutting up the core support to make room for ron davis radiator/ 2nd gen intercooler/ AC condensor/ and trans cooler...it is going to be tight. Unfortunately, radiator is about 3 weeks out...so there will be some more waiting.

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khaoskustoms

· #18 · Oct 6, 2010

Nice fab work!!! That skid plate looks uber beefy!!!

cRiPpLe_rOoStEr

· #19 · Oct 6, 2010

rube bonet said:
Interior is still up in the air, I didn't want anything that was going to get wet, or at least wet and non removeable. Basically, i would like it so the inside could be hosed out. Do you have any experience with lizardskin (or something similar)? I was wondering how effective it was at noise reduction, I would really like the interior to be quiet...relatively speaking. What are most guys doing for firewall insulation/noise reduction?

those ceramic-based coatings are better to thermal insulation than sound deadening but you can still use those aluminized blankets that have a better sound deadening performance (a not so thin one is preferrable for this purpose)... btw what about a vinyl floor liner? i have seen it being used in almost every taxi as it's washable...

twiisted71

· #20 · Oct 6, 2010

<<<- very envious of your welding and access to the punch to make those cool pieces. Forget the Blazer, you should do a Rod and show off your frame work skills!

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