Lifted79CJ7
I'm with Dusty!! You got us all worked up, then nuthin'!! I can't wait to see this engine..... :? :t: :lo1l:
Jack
J20
Sorry for the delay. Still no pistons. I've been working with Performance American Style for a custom ground Crane hydraulic roller cam shaft. (went with a custom ground Crane hydraulic roller cam) Elliot got me thinking about a custom grind. ( Ordered the Edelbrock Pro Flo EFI from Bulltear 3 Jan 2005). Then a NV4500. That should about do it. Should produce enough torque to move the J20 down the road.
Dusty
Have you built your NV4500, if not i would SERIOUSLY consider chasing down the Fully splined OD outputshaft for diesels and V-10s but depending on the t-case you be scouting fot the right input gear, your going to have more torque than a V-10 and V-10's have problems rattling OD off of the stock shaft occasionally. The full splined output shaft is $150 or you can ussually find a rebuilt tranny with the upgraded shaft, also look to a Dodge tranny it might be your best friend, but that depends on the t-case you intend to run.
J20
Dusty, Thanks for the data on the NV 4500 output shaft. I got basic cam specs today. They are as follows: Crane hydraulic roller for .050 .458 Intake lift @ 204 duration. .462 Exhaust lift @ 214 duration. Good for off-idle to 4500 rpm, cruise at 1900 - 2400. Exactly where I want to be. Roller will allow very fast valve action allowing higher mixture velocity, allowing a denser cylinder pack - equal to one or two ounces of boost?
newt
Your cam sounds very similar to the Crane 260 I'm going to be using. The following are DD2K results that you may find interesting for comparison. The TQ ###s should make me very happy.
401 w/ stock bore, stroke and heads, 9.5:1 comp, air gap dual
plane intake, 650 cfm TBI, and small tube headers. Crane 260-2 cam (456/484 lift, 204/216 duration, 112 LCA).
>Here's what DD2K says:
>
>Crane HMV-260-2
>
>RPM HP TQ
>2000 173 454
>2500 219 459
>3000 266 466
>3500 303 455
>4000 342 449
>4500 322 375
>5000 315 331
>5500 296 282
>6000 260 227
J20
Just a side note: The formula I posted earlier for calculating HP is working according to DD2K.
2000 173 454
>2500 219 459 = (2500x459)/5252.101 = 218.48
>3000 266 466
>3500 303 455
>4000 342 449
>4500 322 375 = (4500x375)/5252.101 = 321.29
>5000 315 331
>5500 296 282
>6000 260 227
Remeber, torque is measured, HP is calculated. Pretty cool :lo1l:
J20
Good news! Custom Engine and Machine (the machine shop doing the machine work here in Great Falls, MT) called today and stated the pistons and rings are in. Mike also finished off-center grinding the crank to a final 3.820 stroke. I'll post the exact piston specs from the build sheet in a day or two. Custom ground Crane hydraulic roller cam and matching lifters should be here in two weeks. I ordered the cam through Performance American Style, a very professional outfit. Took the time to work up exactly what I wanted and bested Summit Racing's price for cam and lifters by about $90. Stand by for piston specs.
J20
I’m providing this data in an effort to make it easier for anyone else who wants to do a similar build. Keep in mind there is head work involved, you have to remove about 5cc from each combustion chamber, if you decide to use this stroke (3.820), bore (4.190) and piston combination.
Wiseco Piston Inc. built the pistons (they are beautiful). Job Number 8622, piston forging F6369ZA. Bore size is 4.190 @ a suggested clearance of .0040. Compression height is 1.275. Wrist pin S451, pin diameter .927 (sbc) pin length 2.950. Ring type 1/16, 1/16, 3/16. I think the ring land and grove width and grove root diameter match a sbc 400 bored .060 over. The piston has a .206 dish measuring 33 cm cubed. Intake valve pocket diameter is 2.2 at 18 degrees and exhaust is 1.8 at 18 degrees. The pistons are closely weight matched at 466.6 – 468.4 grams. Pistons came with a matching set of very nice rings.
Lets add up the numbers. AMC theoretical deck height is 9.208, center line of crank to top of cylinder. Started with a 3.68 stroke and a theoretical 2.247 inch rod journal. Off-center ground the crank rod journal to 2.1 gaining .147 inch of stroke. 3.68 + .147 = 3.827. Mine came in at 3.820. So, center of rod journal at bottom of stroke to top of cylinder is 9.208 + (3.820/2, because half the stroke is above center line of crank and half below centerline of crank) = 11.118. Now, Stroke + rod length + compression height is 3.82+ 6.00 + 1.275 = 11.102. 11.118 - 11.102 leaves about .016 when piston is at TDC. I know the numbers on paper may/will not match what I get when assembled which is what I get to do next. I get to put it all together and make sure it all fits. I also get to make sure there is at least .060 clearance between connecting rod and bottom of cylinder and camshaft. Waiting on camshaft. Should have ordered it earlier. Then the rotating assembly - crank, rods, piston, balancer, flywheel and pulley - gets ballanced. Mill the timing gear for camshaft keeper (a must with the roller cam, prevents cam walk), do the valley oil mod and I should have a completed short block.
Mudrat
WOOOF!!!!! I want to see pics and hear an audio clip when that bad boy lights off!!!
What does Dyno PC think your going to get for HP and TQ??
Good luck!!
Mudrat
hohner0006
I am interested in doing this to my 401 but i'm looking for 600+ HP at higher RPM's for drag racing in the mud. I want to go up a class but I'll be competing with 750 - 850 HP F*rds, D*dges & Ch*vies. I will use my cj7 through a t400, 3,000 stall, D20, 4:56 gears, MSD dizzy and 6T box w/rev limiter, Predator carb, dual plane intake, ported heads and run 13 x 37 x 15 Boggers. My biggest hurdle is that I must pull 15" of vaccuum at 800 rpm. I know I'll have a 1,500+ weight advantage on the fullsize guys so I won't need as much HP. A lot of what you guys are discussing seems more for low rpm torque not high rpm HP. What suggestions would you give me on my build-up? Thanks, Hohner0006(I'd post a pic of my cj if i could figure out how!)
J20
My goals/objectives for this build was to significantly best the performance of the ch*vy HT383’s 435 ft-lbs torque at 3500 rpm and 340 hp at 4500 rpm. One sure way to accomplish this is to utilize a stroke longer than 3.75 inches and a bore bigger than 4.030 as there is no substitution for cubic inches given normal aspiration. DD2K says I’ll best the HT383 numbers with no trouble. Had I needed/desired more than 500 ft-lbs of torque or more than 600 hp at any given rpm I would have selected the ch*vy big block. At the risk of offending all, I do not believe the AMC V-8 is a suitable platform for more than 600 hp given normal aspiration and pump gas (especially if you have to maintain 15” inches of vacuum at 800 rpm. That is a very severe cam limitation). I say this because the deck height is simply not tall enough at only 9.208 inches to reliably/realistically fit more than a 3.9 inch stroke while keeping the piston pin out of the oil control ring and with a 4.75 inch bore center the AMC V-8 block is limited to about a 4.25 bore. Given these limitations the maximum cube is about 442 and that is way out there on the edge. An AMC block so configured will not live long because the cylinder walls would be so thin and rod angle too great (A few pages back we listed calculations for my rod angle at 18.6 degrees. Seventeen degrees is the established optimum and over 19 degrees creates exponentially increasing amounts of side-load force). To further justify my position, lets look at a few built examples. The ZZ502 delivers 502 hp at 5200 and 567 ft-lb of torque at 4200 rpm. This is a middle of the road build utilizing a 224/234 hydraulic roller cam and 850 cfm carb and produces about 1 hp per cube at peak and a little over 1 ft-lb of torque per cube a peak. The world power 509 cubic inch Merlin big block ch*vy will produce 540 hp at 5500 rpm, more aggressive 236/246 hydraulic roller cam produces about 1.06 hp per cubic inch displaced. Lets look at the Huntsville 406 ch*vy smb all-out racing motor. Produces 575 hp and 431 ft-lbs of torque at 7000 rpm, 12.9:1 compression (pump gas is out) with Demon 750 cfm double pumper and produces 1.42 hp per cubic inch displacement (15” of vacuum at 800 rpm, I don’t think this engine will run at 800 rmp). Also note the cost per hp goes from $14 per horse ($7,460) for the ZZ502 to $19.65 per horse ($11,300) for the Huntsville 406. Engines running at 13,000+ rpms are very doable but very expensive.
Back to our beloved AMC V-8 before I get inundated with hate mail. If we limit the stroke to 3.82, keeping the piston pin out of the oil control ring, and bore to a more reasonable .060 over 4.225 we will end with 428 cubic inches. If be build for an aggressive 1.5 hp per cubic inch displaced (I’ll give an advantage to the AMC heads and increase the ratio above the Huntsville’s 1.42 hp per cube example) we have the potential for a theoretical 642 hp. BUT we are not running on pump gas as our compression ratio is at least 12.9:1 and I don’t think 15” of vacuum at 800 rpm is possible given the very aggressive cam we would have to use. If we devalue the hp by 12% for a 10:1 compression ratio we end with 564 hp, well below 600 hp. If we add a supercharger…., the rules change. I believe if your looking for more than 600 hp in a normally aspirated, reliable, stay together for more than a few runs down the strip AMC V-8 - you won’t find it. You’ll be better served with a big block ch*vy. Okay – hit me.
jeepsr4ever
That is a interesting point but lets not forget about extra's like block filler. We have a guy here in town runs a 870hp 401 (not sure on overbore) with a supercharger and block filler up to the edges of the water ports. He runs cool all day! And its reliable!
Its true the blocks can only handle soo much for soo long, they arent 1000hp blocks BUT they can handle alot and cubic inch per horsepower is incredible with these engines. I do understand what your saying. a 426-426-428-436-438-500-523-528 cubic inch AMC can and has happened with great results
hohner0006
I appreciate your honesty and bluntness. In the long run , it saves me a lot of time and money! I thought since 406 ch*vies run so damn hard at the track, the same potential would apply towards the 401 AMC. (Just at a higher cost) You seem VERY knowledgeable, so expain how even a bbc or bbf can make 850 dynoed HP and still pull the 15" of vaccuum? Obviously the cubic inches helps but , like you said, the cam limits your full potential. By the way, you are allowed any race fuel except alcohol or nitro blend. Most are running 114 octane but 1 is running 116 vp fuel.
Based on your views of the AMC engine, tell me what you feel I could build for a reliable go fast engine and at what hp range it would take to move a 3,000# jeep 150' quickly. At least quickly enough to run with the 5,000# + big hp trucks. It will give me something to shoot for or reach a decision to abort the whole project. Thanks, Hohner
J20
You are undoubtedly correct about the many possible methods of obtaining more than 600 hp from the AMC V-8 if you use some or a combination of the following: supercharger, special high octane fuel, non-street typical compression ratios, stroker crank (I think you can buy up to a 4.135 inch crank for the AMC), highly modified heads/intake manifold or a very radical camshaft and are willing to accept the significantly increased cost and significantly reduced engine life that will come with some of these combos. You do raise a valid point I failed to consider as my focus is primarily on a 100K+ mile build. You open the door for numerous very potent prospects. Lets consider the supercharged 870 dynoed hp example. Lets say a GM 870 blower is employed and adds a healthy 8 lbs of boost. This will increase fuel/air charge in cylinder about, depending on barometric reading, (8/14.7 = .544217) 54% with subsequent proportional gains in horsepower. Given this scenario, I believe a supercharged 401 can easily hit the 870 hp mark, normally aspirated at 550 hp + 54% + high octane fuel = 870 hp (I realize there is not a 1:1 correspondence between % boost and % hp). Keeping it cool under a continuous 870 hp load will prove very difficult. A 523 cubic AMC block is possible if a 4.135-inch stroke and 4.50 bore is utilized. This combo can be done with a stock 5.85 inch rod connecting rod, a reasonable compression height (maybe a little short with a compressed ring pack) but the cylinder wall finishes at only .25 inch, block filler a must. Rod angle will be over 19 degrees, 20.69 degrees. Stroke divided by 2 then divided by rod length is 4.135/2 is 2.0675/5.85 = .3534, inv sin = 20.69 degrees. A little to much for my comfort. Could use a longer rod and sacrifice ring pack. Hohner, I’ll bet this really has you confused. I would appreciate (read this as need) the opinions of others who are running high horse AMC V-8s. Thanks.
Mudrat
hohner0006 wrote(I'd post a pic of my cj if i could figure out how!)
I'll let the big block techeeeeeess handle the HP side. To post pics, you need to have them somewhere that you can link to. Either your own website/address or an image host. A lot of us use Webshots, or Ripway
What you need to do is while you are writing your post, use the buttons at the top of the posting block. You'll see them listed from B for BOLD to .
To show a picture the format would be 
with NO spaces between the start and finish [img] blocks. To show a link like I did use [url= the link] text . You can also change text color and style the same way.
More questions, just ask.
Mudrat
Mudrat
newt
This is all very interesting, but why do you want to use the 401? I would think it would be much cheeper and easier to run a BB in your jeep and be competitive (I would have thought an auto would be a better tranny choice too). Also I don't think your dana44s will hold up to that kind of power.
hohner0006
To run the CJ I have to run corporate matching motor trans & trasfer case combo. This is what I like about Jeep/AMC, it lets me run my choice of a t400, tf727 or AMC 999. Also, D20, D300, 208 t-cases. BUT I have to run the AMC engine. IF I built up my J4000 (title weight at 5,350#) I would then have the engine choice from the Buick side of GM since 350 buicks were used in production. (I already got a ruling from the Race board that denied me the use of any other GM engine line other than Buick in the p/up and a denial to apply this engine into my CJ since none ever left the factory with one in the engine bay.) My next choice could be the XJ series that had the POS GM 2.8 v-6 in it. I can put a potent 406 stroker or BB in it but their design involving no real frame (uni-body) could lead to structural problems even with a full cage with a high HP SB or BB. If I have to go through this much work I might as well buy a paddle car and not worry about any rules at all. Look up www.southdakotamudracers.com under "classes" at the Super Stock rules as this is my guideline for building up my cj.
So maybe you can see why I want/have to build a potent 401 for my cj. I want the flexibility in my driveline choices and the lighter weight. I know my D44 may be my weak link but I can always put moser or MW axles in it or go to the D60 (add 350+#). I just need to get the engine buildup decided so I can get started on it first. The rest I can get done during the off-season.
J20
Another key consideration for Hohner, in your desire to go 150 feet quickly is that the longer you make the stroke the longer it will take to get the engine to what ever operating rpm delivers max hp. A shorter stroked large bore engine will rev very quickly and develop hp very fast at the expense of torque. (shorter leverage arm/faster motion). The big block crowd simple overcomes this obstacle with sheer brute force via additional cubes. Your gains will have to come via superior volume metric efficiency and gearing as the AMC V-8 is simply not cable of the cubic inch displacement of the big block given 4.75 bore center and a 9.208 deck height. The ch*vy big block has a 9.8 inch deck height and greater bore center. I would recommend to you that you focus less on actual hp and focus on your hp to weight ratio and line up the hp/torque curve with your gear ratios. You have a significant weight advantage, you say 1500 lbs? If so, you can achieve the same results with 600 hp as the bigger rigs can achieve with 850 hp. Your lighter vehicle with quicker to accelerate engine and proper gearing should prove a winning combination.
My recommendation. Use your 401, off-center grind crank - stroke to 3.82, use a good ch*vy 6 inch steel h beam connecting rod, get some good pistons with high compression ratio, open up the heads (Edelbrock AMC performer heads?), have an aggressive cam custom ground (roller or otherwise, Performance American Style can/will help), consider fuel injection, do whatever oil modifications you see fit (consider the Miladon (sp) dual feed system? There are members on this list very qualified to talk to this). Build to operate at 7500 rpm and kick ASS! :lo1l:
Elliott
J20 wroteOkay – hit me.
A nitrous fed 700hp 401 has been running reliably enough for Dave Allen in his race Cherokee ( http://www.daveallenracing.com ), reliably enough that he built a 2nd for his CJ. GM blocks are soft compared to the 401, there is a reason they need 4 bolt mains. If big HP wasn't possible, reliably, of the AMC then I don't think Herman Lewis would have much of a reputation and I don't think ICH would have built the aluminum block for 800+hp on the very same cylinder centers with short compression height pistons.
MC ran some auto cad on the stock 401 block and it sure looks like it could be reliably wet sleeved for 4.374" liners to match up with a 4.15 Moldex crank that ICH uses in the tall deck height aluminum AMC 500ci.
Now, I'm not much on math, but I am a betting man and regardless of rod angle crap I've read about (that seems to be largely ignored by ICH among others, ICH Bracket Master 500 runs 19.55* with only 0.192"s more deck height and 6.2" rods) I'd say a fire breathing 500CI could be built on the 401 core with 6" rods that would pump out over 600ft/lbs easily without race fuel even, much less gas or a super charger.
The AMC block has the same cylinder centers that the Mopar 440 has, how far do they get built? Taller deck height, granted.
The stock 401 has a rod angle of 18.30, with 4.15" throw on a 6" rod for the 500 CI you'd have about 20.20, only slightly steeper then the Bracket Master. Yes, you'd likely need a oil support rail 1.120-1.238"CH piston, but they run those in stroker Mopars... and the Bracket Master 500.
I'm not sure that +.65* of rod angle is anything to sneeze about even with a short compression height piston if you only need 10:1 compression to turn 650+ ft/lbs on pump gas. A 200,000 mi street motor, probably not... but who seriously builds a performance motor to last 200,000 miles? :idea: Just my .02 and I haven't built any 401 that even desktop dynoed over 500ft/lbs for 5-6 years. You have enough nickle in that AMC block to throw what ever you want at it in my opinion. I wouldn't hesitate to put it up against any big block out there.
J20
Elliot, glad you wrote, what took so long? If your building a long life motor you need to consider rod angle because the ovalating forces exerted on the rod mains will literally tear the rod main apart if the rod angle is too great as rpm increases over 4500, I think 19 degrees is the limit for a long life motor (over 100K miles). Forged steel rods, balanced and blueprinted components are a must for applications exceeding 19 degrees and 4500 rpm. As for the high nickel content of the AMC block, it is not that much higher than others, try a punch test and you’ll find little difference. A trip to your local machine shop will reveal little difference in the machining or hardness characteristics of the AMC block vs. others. The Mopar 440 is a strong motor but there is a reason it is no longer is production or a first choice race application engine – it simply does not have the endurance or reliability of others (I'll catch H*ll for that one). Having said all that, I do not dispute the ability of those (and they are much more knowledgeable than I) who get upwards of 450 cubes and over 600 hp from the AMC platform. My point is that the AMC block, from an engineering/construction standpoint better correlates with the small block ch*vy than the big block ch*vy and we can’t realistically ever expect to exceed the potential capability of the ch*vy big block. We can however easily exceed the potential capability of the ch*vy small block.
I will concede that what I am building and the builds Elliot speaks of are vastly different. If the big block ch*vy crowd applied the same proportional gains they would hit the 600 cube mark and generate 200 hp more (at a minimum) than the 500 cubic inch AMC. See my point? To achieve big block ch*vy performance levels the AMC user must push the platform to greater extremes, greater extremes increase the probability of failure given the same conditions. If you are willing to accept those increased risks, by/buy all means build away.
