Cummins or Cadillac?
- Thread starter Woofwagon
- Start date
justcuz
Explorer
What are the final cam specs going to be? Lift, duration @050 and lobe center. Modern cams with roller lifters can achieve high lift, with decent duration AND wide lobe centers (over 112 degrees) because the roller lifters allow the ramps to be ground steeper.
Your earlier comment about Caddy cams being just about round cracked me up, it leaves lots of room for improvement!
I have my eye on an old Travelall and if I get it I am thinking big Caddy or Olds engine too.
Your earlier comment about Caddy cams being just about round cracked me up, it leaves lots of room for improvement!
I have my eye on an old Travelall and if I get it I am thinking big Caddy or Olds engine too.
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Woofwagon
Adventurer
I'm not going to run a real wild cam. The valve springs and train in the stock Caddy engine don't like high rates of speed. The valves, spring and seals will of course be replaced. I will have the heads done here shortly with a 3 angle job combined with a port and polish. I don't plan on running this engine past 4500 rpm. That said I'm still noodling over the extra cost of a roller valve train. I think long term it would help in terms of cam longevity in that I wouldn't have to run a zinc substitute in the oil. I do plan on running 15W40 diesel engine oil as these are a loose tolerance engine with generous clearances. MTS (Maximum Torque Specialties) has a very good RV type cam grind that has lots of bottom end torque which the Woofwagon will take advantage of. I may change the differential ratios from a 3:73 to a higher ratio or just spend the 2 grand and put on a Gear Vendors. I'm designing the gearing so that I can have good freeway economy for this engine and still keep the engine in its torque sweet spot. The book "Big Inch Cadillac" has been most helpful in me spec'ing out this build. The goal is build a torque monster that is ultra-reliable and simple to fix should the situation arise.
justcuz
Explorer
For the same cost as a Gear Vendors, you could have a built 700R4. That would give you a lower first gear than the Turbo 400 and a higher OD than the Gear Vendors. 3-1 first gear and .70 overdrive.
Plus you can source a BOP bell housing trans to bolt right up to your Caddy engine.
The biggest issue with the 700R4 is the gear split between 1st and 2nd gears, but with the Caddy torque and a good trans cooler, it should be a non issue for your application.
Plus you can source a BOP bell housing trans to bolt right up to your Caddy engine.
The biggest issue with the 700R4 is the gear split between 1st and 2nd gears, but with the Caddy torque and a good trans cooler, it should be a non issue for your application.
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superbuickguy
Explorer
yes, but that's a qualified yes. You'll have $2500 in the transmission and you'll have to get an adapter. On top of that, you should build an electronic (4L65e - not 4L60e) transmission so you get heavier-duty internals and the ability to program the shift points depending on conditions rather then trying to find a be-all, do-all transmission programmer for the 700r4.
justcuz
Explorer
Yes and no.
The 500 Caddy is a BOP (Buick/Oldsmobile/Pontiac) bell housing is it not? If so no adaptor is required. As I stated before, these transmissions were used in full sized cars in the late seventies when GM downsized all their big cars. My co-worker had a Caprice wagon with an Olds engine in it from the factory, so BOP 700R4 transmissions are out there.
4L65E mechanical upgrades are commonly installed in 4L60E transmissions which is an electronic valve body version of a 700R4. 700R4 is not electronically shifted and works with carbed engines with only the addition of the TV cable and a lock up torque converter switch. No stand alone computer is required for the 700R4 transmission.
700R4 transmissions are used behind big blocks in aftermarket applications, so I am sure you can make one live behind the Caddy. Check out Bow Tie Overdrives and some other internet vendors of these transmissions.
I looked online yesterday and a Gear Vendors is 3500 dollars new, so a transmission is still cheaper than a new Gear Vendors Overdrive.
The 500 Caddy is a BOP (Buick/Oldsmobile/Pontiac) bell housing is it not? If so no adaptor is required. As I stated before, these transmissions were used in full sized cars in the late seventies when GM downsized all their big cars. My co-worker had a Caprice wagon with an Olds engine in it from the factory, so BOP 700R4 transmissions are out there.
4L65E mechanical upgrades are commonly installed in 4L60E transmissions which is an electronic valve body version of a 700R4. 700R4 is not electronically shifted and works with carbed engines with only the addition of the TV cable and a lock up torque converter switch. No stand alone computer is required for the 700R4 transmission.
700R4 transmissions are used behind big blocks in aftermarket applications, so I am sure you can make one live behind the Caddy. Check out Bow Tie Overdrives and some other internet vendors of these transmissions.
I looked online yesterday and a Gear Vendors is 3500 dollars new, so a transmission is still cheaper than a new Gear Vendors Overdrive.
Woofwagon
Adventurer
The Caddy is a BOPC bell housing pattern. There are Chevy and BOPC pattern TH400 transmissions. An adapter isn't a huge deal, I can get one for 60 bucks. I know that I can get a fully rebuilt and beefed 700R4 for about $1300 bucks with a core. I just have to make sure my existing transfer case is going to mount up to a 700R4. I need to climb under and find out if it is indeed a NP205 (hoping). I think that with 3.73s in the diffs and an overdrive, I can keep the revs down on the Caddy and keep it in its torque sweet spot on the freeway.
justcuz
Explorer
Your Turbo 400 has a 32 spline output shaft. The Turbo 350/700R4 has a 27 spline output shaft. Your t- case will need an input shaft swap or trade or buy a 208 or 241 with the correct splined input.
A 205 has a 1.97 to 1 low range.
A 208 has a 2.62 to 1 low range.
A 241 has a 2.72 to 1 low range.
A 208 or 241 will have a round aluminum tag on the rear of the case with the type and low range ratio stamped in it.
208 and passenger drop 241's should be easy to find, 208's more common on passenger drop and cheap at the wrecking yards. Dodge used 241's behind their 2nd generation diesel so no worries about strength for your application.
I would guess you have a NP 208 aluminum case based on your model year.
I think only 1 ton trucks came with a 205.
A 205 has a 1.97 to 1 low range.
A 208 has a 2.62 to 1 low range.
A 241 has a 2.72 to 1 low range.
A 208 or 241 will have a round aluminum tag on the rear of the case with the type and low range ratio stamped in it.
208 and passenger drop 241's should be easy to find, 208's more common on passenger drop and cheap at the wrecking yards. Dodge used 241's behind their 2nd generation diesel so no worries about strength for your application.
I would guess you have a NP 208 aluminum case based on your model year.
I think only 1 ton trucks came with a 205.
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Woofwagon
Adventurer
Been ultra busy on other projects and an unexpected repair to my diesel Mercedes has set me back by $2700. Yes you read that right. All because some politician thought it would be a good idea for the environment to put a catalytic converter on a diesel engine. Morons. I'm gutting that cat as soon as I get the car back.