Jeep Enthusiast Forums banner

401 swap update. HP estimates break in Q's too.

5K views 84 replies 9 participants last post by  jeepdj5 
#1 ·
Finally Had some good weather. Got the 401 painted up and assembled.

Tire Automotive tire Wheel Motor vehicle Red


Car Wheel Tire Land vehicle Automotive parking light


Vehicle Motor vehicle Hood Automotive design Car


I got it mated yesterday before I called it quits before sundown.

Feel free to chime in. I have a lot invested here

From what I understand on a new engine you prime the pump with old dizzy.
Use oil with zinc.
Just to be safe add octane boost to the tank of regular unleaded because it's 9.5:1 ratio.
Run 20 minutes between 2,000-3,500 RPM
Drain oil and replace filter.
Drive up some steep grades. In the few thousand miles to set rings (TRUE?)

When can I go do a dyno pull?

Or do you think I met my goal of 400HP 450ft/lbs?

MSD coil, dizzy, and wires
Edelbrock Performer intake
670cfm Holley TA ( do I need more carb?
.30 over
9.5:1 plugs
5-angle valve job porting too
Crower stage 2/3 cam
INT/EXH - Dur @ .050" Lift: 212°/220° RR: 1.6/1.6 Gross Lift: .464"/.488" LSA: 112° RPM: 1500 to 4500 Redline: 5000

I've been asking around a few other threads and the only answer I got was 350HP

What else could I do to have a street able 400HP?
 
See less See more
3
#3 ·
I find it interesting that the HP ratings for the 401, in 1971, were 330HP @ 5000 RPM and 9.5:1 compression, stock.
In 1977 that number went down to 195HP @3500 RPM and 8.25:1 compression. So whats the real base HP rating of the stock 401?
 
#4 ·
SAE vs NET rating system. Run a high zinc oil like Joe Gibbs driven or Brad Penn the parts store crap w additive won't be enough. Run that less than 400 miles then swap it to a longer duration non break in but still high zinc zddp.
 
#5 ·
Don't know if this helps..... Here's the dyno specs from the 401 I just installed..... Yesterday was first start day after install......
427 Max HP @ 5300 RPM's
498 Max Torque Ft. Lbs. @ 3900 RPM's

Sent from my iPhone using JeepForum
 

Attachments

#6 ·
I got a case of CompCams break in oil. Thanks for the info.

Captainak- can you give me some of your specs on your build or is it close to mine?
And how long did you run it after break in before you did a dyno pull?

That is some impressive power by the way.
 
#7 ·
U had mine built from CMEngines in NC ...... I really don't know much about my build except that I was first 401 they've done as they do exclusive 360 and 304 for racing..... It's 10:1 compression, choppy idle and has oiling mods..... Doesn't have roller rockers but I was told it would put another 15-20 HP ...... I figured I already had 6500 in the build ..... It was dyno'd with the edlebrock thunder series I have on my old 304 and it didn't pass specs so it now has a Quick Fuel Tech VS 680 on it and is very responsive ..... Running Holley blue eletric fuel pump

I'll see if I can get more info

Sent from my iPhone using JeepForum
 
#8 ·
Wow. I actually looked at the dyno chart closely this time and 485ft/lbs at 3500-4500 is impressive. I was going to ask if your running a stall converter but with that much torque in the lower RPM's you probably don't need it.
I'm sure rollers and a bigger carb could make you some more easy.
If you could share more specs I'd appreciate it.
 
#9 ·
I threw an email to them ..... All I have is a receipt with pretty much no details .....

The following is why I didn't worry about details ....

"CAROLINA MACHINE ENGINES for over 28 years has hand built over 50,000 Remanufactured Automobile and Marine engines, also Street Performance Pump Gas Crate engines and World Champion Racing engines. Sold at 'Factory Direct' prices. Our 'Better Business Bureau' rating is A+ , their highest rating available."

CAROLINA MACHINE ENGINES is an expert at extracting the most horsepower and producing the most dependable High Performance Pump Gas street engines available. We are able to do this because of our long time involvement in racing and performance street rodding 'and' because of our experience as a Production Engine Remanufacturer (PER).

Although we produce "high end" Performance and Race engines with expensive parts, we also produce more economical engines that use one or more of the stock OE parts such as block, crank, rods, heads, oil pan, etc. These engines can produce amazing horsepower and give good long service when "done right". We have the ability to accomplish this because of knowledge and experience gained from decades of racing under basically "stock" type rules and regulations of the various sanctioning organizations.

Each of our engines receive all new high Quality internal components, including performance valves, forged or hypereutectic pistons(when available), moly rings, brass expansion plugs, premium rod and main bearings, cam bearings, pushrods, valve springs, rocker studs, hydraulic lifters, rocker arms, timing chain set, and a specially chosen and dyno proven performance camshaft.

We use the highest quality brand parts such as ACL, B&B, BULLET, COMP CAMS, CLEVITE, CLOYES, DURA-BOND, EAGLE, EDELBROCK, ELGIN, FEDERAL MOGUL, FEL-PRO, HASTINGS, HOLLEY, JESEL, K-LINE, LUNATI, MAHLE, MANLEY, MELLING, PERFECT CIRCLE, PIONEER, PROBE, RHS (Racing Head Service), SCAT, SEALED POWER (Speed-Pro), STEF'S, SILVOLITE, STERLING, US SEAL, US TOOL, VICTOR-REINZ & WEIAND.

Many people make their final choice based on the vacuum and idle characteristics of the engine. See the "Idle Type" column above with the engine pricing.

"CHOPPY" idle is a very noticeable performance idle and will have a somewhat lower manifold vacuum, 10 to 12 inches. We recommend quality headers and a torque converter in the 1800 to 2800 RPM range. This is basically a rougher "Muscle Car" idle. We define these engines as "Almost Daily Drivers".

http://www.cmengines.com/Home/tabid/36/Default.aspx

Sent from my iPhone using JeepForum
 
#10 ·
Or do you think I met my goal of 400HP 450ft/lbs?

MSD coil, dizzy, and wires
Edelbrock Performer intake
670cfm Holley TA ( do I need more carb?
.30 over
9.5:1 plugs
5-angle valve job porting too
Crower stage 2/3 cam
INT/EXH - Dur @ .050" Lift: 212°/220° RR: 1.6/1.6 Gross Lift: .464"/.488" LSA: 112° RPM: 1500 to 4500 Redline: 5000

I've been asking around a few other threads and the only answer I got was 350HP

What else could I do to have a street able 400HP?
You might have 400hp at the crank, but you'll never really be sure if you're going to do a chassis dyno pull. Looks more like the 350-375 range to me. If it isn't there you'll probably have to do more extensive head work, with possibly a cam change. Think airflow and friction reduction, which is expensive.

What's more important than a number is the smile on your face you'll get when you feel the amount of torque the 401 makes and the big RPM range that it makes it in.:thumbsup:
 
#11 ·
I guess the torque really is what matters off the line.
I convinced my fiance to let us drive the Wag down to South Texas this summer for our honeymoon.
I really just want my soon to be wife to be stuck to her seat when I punch it and pass people on the freeway with confidence :D
 
#12 ·
revelc said:
Wow. I actually looked at the dyno chart closely this time and 485ft/lbs at 3500-4500 is impressive. I was going to ask if your running a stall converter but with that much torque in the lower RPM's you probably don't need it.
I'm sure rollers and a bigger carb could make you some more easy.
If you could share more specs I'd appreciate it.
This is what I was sent by email.....

Sent from my iPhone using JeepForum
 

Attachments

#13 ·
Captain- they didn't give cam card info, head work done, intake used, oiling mods, porting done?
Not to be rude but that email was just telling you the do's/dont's of your build. Not the actual specifications and recipe used.
With that much money invested I would want to know. Maybe that's just me.
 
#14 ·
revelc said:
Captain- they didn't give cam card info, head work done, intake used, oiling mods, porting done?
Not to be rude but that email was just telling you the do's/dont's of your build. Not the actual specifications and recipe used.
With that much money invested I would want to know. Maybe that's just me.
I'm a word of mouth and end results guy ..... Not really into the particulars of the build... As I know a lot of people are..... I knew from my military jeeper circles that these guys produce quality and all I was asked when I called was how much HP (375-500) I wanted ...... Guess Im not much a a detail guy...... But still wish I had the info to pass along lol ..... Sorry :(
She is pretty though

Sent from my iPhone using JeepForum
 

Attachments

#15 ·
Thanks anyways.

That's thing looks slick.

Love the serpentine set-up and alternator bracket.

I think the only performance part you have that I do is the dizzy lol
 
#16 ·
Well I got the tranny bolted up. Along with a few accessories. Now I need to switch out the leaking Saginaw pump while the gettins good, slap the carb, radiator, and dizzy in and she's good to go.

Motor vehicle Automotive design Automotive exterior Automotive lighting Auto part


I dismantled the old distributor and made myself a priming pump. I may have overdone it but I filled the oil filter with assembly lube/break in oil before I put it on. And used 6 quarts of Comp Cams10/30 break in oil to make sure there was enough running through for the break in.

Tire Motor vehicle Automotive tire Tread Wheel


Still wondering if I want to start it with open manifolds or not. I want everyone to hear it :D I just don't want a tick or rattle to go unnoticed with the 401 music turned up.
 
#17 ·
revelc said:
Thanks anyways.

That's thing looks slick.

Love the serpentine set-up and alternator bracket.

I think the only performance part you have that I do is the dizzy lol
I honestly can't wait to just run this thing I've had the cj since 2009 and have MAYBE 4 months drive time.......

Yeah that's the bulltear system I'm going to do there double oil filter sys this summer as well

This is the list of every thing I've put on the engine.....

Quick Fuel Technology
Street Carburetor 680 CFM VS
Part#: SS-680-VS

Holley 2 110 GPH "BLUE" ELECTRIC FUEL PUMP WITH REGULATOR

Edlebrock Performer Intake (Powder Coated)

Aluminum Valve Covers (Powder Coated)

MSD Blaster 2 Coil Hi-Performance

MSD Pro-Billet Ready to Run Distributor

MSD Ignition Control 6A

Moroso Blue Max Race 8mm Wire Set

Professional Products 91102 AMC Harmonic Dampener

Bulltear AMC Serpentine Aluminum Pulley Conversion Kit

Oil Pan w/ Custom Built 3/8 Aluminum Skid Plate (Hurculined)

Headman Hedders Wrapped and Coated with Design Engineering Black

Milodon 16271 Performance Aluminum High Volume Water Pump for AMC

Northern 19 X 24" Double Pass Race Pro Aluminum Radiator w/Right Side Inlet/Outlet

Summit Racing Street & Strip Electric Fan, 16 inch, 2,010 cfm
(Pusher)

Flex-a-lite Low Boy Electric Fan, 16 inch, 2,500 cfm
(Puller)

Daystar Polyurethane Motor Mount Black

Centerforce 700730 BILLET STEEL FLYWHEEL

AGR Performance Super Pump Power Steering Pump

Sent from my iPhone using JeepForum
 
#18 ·
Post the vid of first start!!! Can't wait!

Sent from my iPhone using JeepForum
 
#19 ·
Captainak said:
I honestly can't wait to just run this thing I've had the cj since 2009 and have MAYBE 4 months drive time.......

Yeah that's the bulltear system I'm going to do there double oil filter sys this summer as well

This is the list of every thing I've put on the engine.....

Quick Fuel Technology
Street Carburetor 680 CFM VS
Part#: SS-680-VS

Holley 2 110 GPH "BLUE" ELECTRIC FUEL PUMP WITH REGULATOR

Edlebrock Performer Intake (Powder Coated)

Aluminum Valve Covers (Powder Coated)

MSD Blaster 2 Coil Hi-Performance

MSD Pro-Billet Ready to Run Distributor

MSD Ignition Control 6A

Moroso Blue Max Race 8mm Wire Set

Professional Products 91102 AMC Harmonic Dampener

Bulltear AMC Serpentine Aluminum Pulley Conversion Kit

Oil Pan w/ Custom Built 3/8 Aluminum Skid Plate (Hurculined)

Headman Hedders Wrapped and Coated with Design Engineering Black

Milodon 16271 Performance Aluminum High Volume Water Pump for AMC

Northern 19 X 24" Double Pass Race Pro Aluminum Radiator w/Right Side Inlet/Outlet

Summit Racing Street & Strip Electric Fan, 16 inch, 2,010 cfm
(Pusher)

Flex-a-lite Low Boy Electric Fan, 16 inch, 2,500 cfm
(Puller)

Daystar Polyurethane Motor Mount Black

Centerforce 700730 BILLET STEEL FLYWHEEL

AGR Performance Super Pump Power Steering Pump

Sent from my iPhone using JeepForum
If the shop that built your engine did the valley oil mod I'd say you have a near bullet proof setup. I hope the rest of the Jeep is ready for all that power. I'm really impressed with those HP numbers using a Performer intake.

What exactly do you plan to do with it?
Hot street?
Show Jeep?
Trail rides? If your off roading you need to rig a kill switch for those nice electric fans if you pass through some water.

Sounds like you have a really solid build. I bet you can't wait for your down time/drive ratio to improve :D
 
#20 ·
I did have the t-18 rebuilt and swapped out the Dana 20 for a rebuilt jeepster dana 20 with twin stick conversion for front only wheel drive.... I went with the Centreforce Dual friction clutch plate and converted to hydraulic clutch as well....

Now my weak point....

"Loose" drive lines, AMC 20 and Dana 30 Axles (came with but have single axle conversion, true-trac front and Detroit back lockers, 4:11 gears)

Next step......

Currently on the hunt for (not in a hurry)
1: Front End / Axle
Military CUCV Trucks type
M1028 or M1031 (ambulance)
Dana 60
Open Knuckle
Trac-Lok limited slip locker

2: REAR
Military CUCV Trucks type
M1008
Dana 60
GM 10.5"
Corporate
14 Bolt
Full-Float, Differential with No-Spin lockers (Detroit Locker)

3: Will do the trusses and disc break upgrades

4: have not decided to do the superlift 4 link suspension or the cj to yj conversion......

5: I'll convert to the Mil hummer bead lock set up and will go with mil spec hummer 36.5" tires that are readily available in lots or individual for about 150 a piece

This is a trail/hunting and had the cam set to be able to sand dune with high rpms, as well "summer toy"......I have no singular interest

Ill also try a couple shows this summer .... Jeep Jamboree in OH and the Bantam Festival in PA

What about your rig?? What mods or purpose are you building yours for

Sent from my iPhone using JeepForum
 
#21 ·
2: REAR
Military CUCV Trucks type
M1008
Dana 60
GM 10.5"
Corporate
14 Bolt
Full-Float, Differential with No-Spin lockers (Detroit Locker)
Probably just a typo, but that Dana 60 doesn't belong there. These are the same axles you find under a K30 Chevy pickup, with the addition of the Detroit locker. It's hardly worth trying to find a CUCV to steal the axles from.
 
#22 ·
CSP said:
Probably just a typo, but that Dana 60 doesn't belong there. These are the same axles you find under a K30 Chevy pickup, with the addition of the Detroit locker. It's hardly worth trying to find a CUCV to steal the axles from.
Actually the dana 60's under a CUCV are 14 bolt identified and the come with 4:56 gear and Detroit locker already installed........ There are plenty around I'm just waiting to find the "buy me now price"

Sent from my iPhone using JeepForum
 
#23 ·
No, the front axle is a Dana 60. The rear axle is a GM full float 14 bolt. It's not a 14 bolt Dana 60. There is no such thing. All Dana 60s have ten bolt covers.

I used to own an '85 M1028 with the communications cover on the back, so I'm very familiar with the running gear.
 
#24 ·
Ohhh ok I got you..... I just copied pasted from another forum!!! I love these forums! Because there really are a lot of ppl with a wealth of knowledge. Thanks!

Sent from my iPhone using JeepForum
 
#25 ·
Captainak said:
I did have the t-18 rebuilt and swapped out the Dana 20 for a rebuilt jeepster dana 20 with twin stick conversion for front only wheel drive.... I went with the Centreforce Dual friction clutch plate and converted to hydraulic clutch as well....

Now my weak point....

"Loose" drive lines, AMC 20 and Dana 30 Axles (came with but have single axle conversion, true-trac front and Detroit back lockers, 4:11 gears)

Next step......

Currently on the hunt for (not in a hurry)
1: Front End / Axle
Military CUCV Trucks type
M1028 or M1031 (ambulance)
Dana 60
Open Knuckle
Trac-Lok limited slip locker

2: REAR
Military CUCV Trucks type
M1008
Dana 60
GM 10.5"
Corporate
14 Bolt
Full-Float, Differential with No-Spin lockers (Detroit Locker)

3: Will do the trusses and disc break upgrades

4: have not decided to do the superlift 4 link suspension or the cj to yj conversion......

5: I'll convert to the Mil hummer bead lock set up and will go with mil spec hummer 36.5" tires that are readily available in lots or individual for about 150 a piece

This is a trail/hunting and had the cam set to be able to sand dune with high rpms, as well "summer toy"......I have no singular interest

Ill also try a couple shows this summer .... Jeep Jamboree in OH and the Bantam Festival in PA

What about your rig?? What mods or purpose are you building yours for

Sent from my iPhone using JeepForum
Well. This thread is getting off topic. But I'm cool with that.

Your not going to have many original parts left on that thing lol.

I'm hoping my 31" M/T's don't require me to upgrade my axles.

They are literally the only original drive train components left. From the Radiator to my new driveshafts its all new or NOS.

I have the stock AMC 20 in the rear and a 44 up front that I welded for take offs in 4x4 and pulling myself over obstacles.

Yours sounds like a beast.

But the main purpose is to have a fast go-anywhere workhorse for my missions work abroad. And if I get to surprise trucks and Hondas on the streets here too it's icing on the cake.
 
#26 ·
Got a small tach, coolant, a few odds and ends.

When I tried to mount the exhaust manifolds I found that the old bolts from the 360 don't fit. No part stores carry them. So I guess I'll head to ACE and get some grade 8 bolts with some anti-seize.

My priming shaft tool a while to work I had to fill the filter with the rest of my assembly lube and run the drill for about 5 minutes before I put it in high speed mode then after about 20 seconds it bogged down.

I found a new headache though. The dang dipstick tube was a pain to install and when I tried to put the dipstick in it won't go all the way down. I think it went in wrong and either became bent or its hitting the windage tray. CRAP!
 
#27 ·
I have the same issue with my dipstick and was the same on my rebuilt 304..... I'm gonna whack .5" off mine to see if it stops

Sent from my iPhone using JeepForum
 
This is an older thread, you may not receive a response, and could be reviving an old thread. Please consider creating a new thread.
Top