Ok, I have about a week to finalize the specs on my build. I would like to hear your experience on the head and cam specs.

Here's what is in process.
421 Dart SHP block
Callies crank and rods/Weisco pistons. 10.7 CR
HSR on OEM computer/MAF system
1 5/8 headers with single exhaust.
TKO 5 speed/3.27 rear gear

Has to be tunable and very streetable. Cruise rpm ~2K looking for 5800 peak. Target is ~480 honest, net flywheel power with big torque in low and mid ranges.

Choices to be made.

AFR 195 or 210 heads. I am leaning toward the 195's to keep the low/mid snappy but this is a fairly big CI motor and the 210's may be ok.
Comp cams hydraulic roller. I'm thinking 236/242 cam on 108 with ~600 lift. Probably custom grind with short travel, retro-rollers.
I have been advised by 2 different techs at CC to run 248/254 on 110 or 254/260 on 113. It seems this would be too much cam and maybe a bear to tune.

Please share any experience you have with this type build. I have to give my builder my specs in the next few days so he can order the remaining parts while my short block is going together.

Remember, I want this to be almost docile at idle and lower/mid range but surly don't want to be too conservative. As long as it pulls great at cruise and I can tune it reasonably I want all I can get.

 

I like this on a comp magnum high lift lobe with 210's for a broad powerband and great manners. 108 will have some lope. But be tuneable. Going wider lsa will stabilize more but stock maf system will be fine. I did a similar cam in a 383 hsr that drove incredibly well despite the sinister idle.

That cam is a great street setup imo. Lobes arent valve train eaters. Its not large by anymeans and will fit your power band.

You can definately go bigger and still be fine for tuning however your small exhaust wont help the high 240's cams. It would want to spin 6500 rpm which really needs a 220 head and big tube header. My 400 tuned great with a 246/252 on 730 speed density and would be easy on maf but the rpm range is way outside your range and it gives up some bottom end

Afr has a pretty fast port head and a pretty fast burn chamber. They act smaller than other heads out there. 210 is not big at all

 

210's with the 236/242 cam. The manual trans will appreciate the bottom end grunt. It will also minimize bucking/surging at low revs. A friend of mine has an over cammed 355/6 speed and the cam surge under 2500rpm makes him not even want to drive it anymore...

My carbed 396 with Dart 230's and a Comp 254/260 idled at 1200, shifted at 7000. With a 3000 stall converter, it was hard to do a burnout(even in the waterbox!)...weak bottom end! It needed a 4500 stall to make it happy.

 

Thanks guys, this is exactly the input I need. The situations you describe are exactly what I am trying to avoid. And Orr has followed/commented on a couple of my threads on this build and is familiar with what I am trying to achieve. A fun, powerful street car. Something my wife could drive if she ever gets the urge. Most hear I am building a 421 and presume I'm going for broke. That's not my plan. I want to get as close to my power goal as possible with a well behaved combo. Keep the info coming.

Now I am trying to decide which lobe family I should use. As Orr mentioned the Mag/high lift series, and it's a contender. But the XFI's are still in play as are the XE, QXx/QNx, and even the XE marine. I am looking at the .050 dur and then looking back at the advertised and then over to the .200 with an eye on lift with 1.6's. (make sense???) Anyway, I still want to select an aggressive lobe without taking too big of a hit on the valve train/guide life. I wouldn't mind changing springs in 20K miles but need the guides to survive considerably longer. Also, it seems the OEM style roller lifter guide limits lobe lift to ~.360 so I may go with the link bar type to have more options there. Anyone have experience with 1.65+ ratio rockers on the street?

 

Guide life will be really dependent on geometry of the rockers. If setup properly there will be little side loading of guide wall. Get it wrong and you'll wipe them out if you have stiff springs. Afr 8019's shimmed a touch .015-.020" will handle any cam and still can use oem lifters. Thats what i used with my magnum hi lift 230 .603 and 245 .613 lobes.

However a xfi in the .570-.580's range would still make massive power. Given lower rpm range you wont need huge lift but enough to help that 421 breathe up top. Regular xe lobes with a 1.65 could work too and be very nice on parts.

 

Remember.. any of the largest CID small blocks. Will smooth out the larger cams. I'm talking over 415 CID. And get some heads and nothing smaller then 1 3/4 headers..

Going with a 4.00" stoke or
the 3.875.

 

Yup dyno don shorty would be nice here. Big inches is alot of airflow. Require cams you think are to big and heads you may think are to big if you are used to common 355-383s like most of us here

 

Yep...and they dont sound or feel like a small block any more...thats the part I love!!
but ya have to move up in the cam size..heads...and exhaust..and they love EFI.

Takes a few bucks but you can make a easy 600hp driver. Before power adders.

 

Yes, the headers are a hold back- for now anyway. May upgrade the entire system later.

I'm just trying to get the top end and cam sorted out. And Arctic, if you're asking, it's a 4.155 x 3.875 motor.

AFR 210's seem to get the nod.

The "latest" rec. from comp is the XFI lobes, 236/242 on 113. I still like the XE high lift lobes better. Even if they require link bar lifters. I just can't seem to get over the wide lobe center Comp recommends. I get that it pulls the overlap down but "how much is too much"? I'm thinking 65-70 overlap would still pull enough vacuum for brakes/accessories with the large CI. That could still be done with closer to 108/110 LSA. David Vizzard makes a firm point about tight centers with big CI-. Giving the valve a head start on the piston. Makes sense to me. On the flip side the wide center puts the exhaust valve early. Late intake & early exhaust causes problems on both ends. But then DV isn't tuning EFI- 104 would net about 82 overlap with 236/242 lobes. I give a lot of weight to your experience in this area. Tuning that is. I don't feel required to make it run in closed loop. Not emission tested here so pretty much anything goes.

Lastly, the lifter type also has to be decided. OEM style Comps or LS1s should do the trick. And the link bar are also in play if I go with over .360 lobe lift.

Does anyone have experience with the "short travel" type lifter? They are available in both types and are within budget. (which by the way has been blown out of the water lol ie doubled) The way it was explained to me they are basically a solid roller with a hydraulic cushion. "0" lash and they never pump up. But do they need periodic adjustment and are they worth the extra $$?

 

I ran 78 deg advertised overlap on a 383 in closed loop just fine but went open loop because i had a minor issue with restart leanout while o2's were not ready yet lol i believe i know how to fix that issue now tho

Case in point is you can get away with alot more cam and tune fine but is it worth while for your goals? Stockish like sound and driveability?

Comp throws xfi lobes on 113 for any efi build because they must still think wide centers are needed for o2 sensor systems. Its not. You i wouldnt go tighter than 108. 109-110 is a good compromise for alittle less lope at idle and def less chance of minor cam surge with stick shift. After having a 233/233 112 cam in a 400" motor and now 246/252 113.5, its a big difference in idle manners but both drive very well in my automatic. The 233 with afr 195's was all brute force 0-5500 rpm and had excellent manners. A tight lsa you will hear the cam but it will be a fantastic driver with only 236 deg

If budget is tight, save it by going oem ls7 lifters and magnum high lift lobes. Or even base xe lobes with 1.65 rocker

 

Thanks for specific numbers and description.

Yes, I feel the recommendations are conservative. 236/242 @ 113 should net 64* (at advertised) overlap and 110 pushes it up to 70*. Still not a whole lot. But the my tuning experience is with about 42* OL.

Please clarify what you mean by "it's a big difference in idle manners" with the two applications you mentioned. I don't really care about the "sound" but manners, very much. It seems the tighter LSA would cause more lope at idle due to the OL but off idle torque should be better. Again, maybe I am thinking this too much. Blowing the tires out doesn't really get me anywhere and maybe a bit more RPM would let her wind out better. And if this ol man can't tune it right I am even worse off.

 

Original build small cam

Big cam

By manners they both were stabil and idled well but big cam needed more idle rpm and def had noticeable lope and alittle more volume to sound.

The more stockish idle sound would be a low 230's on a 113-114 but it would give up some mid low end power. Not a big deal because 421 cubes will already make way to much torque as it is lol.

 

Let me just say. The mechanical roller cams off today and the poly locks do not require adjustments like they did 40 years ago.once they are set you're good for a year at a time. And even at that time all you're doing is a checkup. I have run mechanical roller cams only for the last 25 years. And I've never had any need re adjust mint. The only time I play with them is too widen the lash for more bottom end.or tighten the lash for more top end.and that's just playing around.

if you want to go mechanical roller. Then go yeah I'll spend a little bit more cash up front but there a lot more fun and make more power.
you don't have to run bronze gears on your distributor. Because you can have cast gears pressed on to a bullet roller cam.that's what I have them do.take care of thwm and that last a lifetime....

I had a guy at my last job working in the aerospace industry. He was a machinist. Try to tell me that a hydraulic roller would always make more power than a mechanical roller...I don't know what he was thinking...maybe some more schooling would help.

 

Thanks for the video clips. And BTW Orr, you're a mad man. When you walked around to the engine bay and I saw those two turbos on top I had a big ol grin. lol. You can write "twin turbo" but seeing it and how it's routed and set up is different.

Not to jack my own thread but I noticed what looked like two different exhaust approaches. I know the turbos change the game but on the first one it looked like maybe a typical 1 in 2 out setup and the second had a couple of resonators in the back. I'm wondering if you ran twin pipes to the rear or just Y in Y out. That had to be a wild routing either way. I have to do something with mine eventually but don't want to lose ground clearance on it. Suggestions?

 

Right here, I'm using Comp Cams short travel lifters and I love them. As far as valve adjustment, they recommend 1/8 of turn for pre-load. And no you do not have to readjust them like solid roller. I have had them in the car going on 2 yrs. now with no issues.

 

Yeah first turbo build had a single 4" split into dual 3" tail pipes over axle. Then i went dual 3" with bullets. New build with new heads and cam for some reason was much louder. Must have been more air flow from all the new parts. I added two mufflers to the 3" dual system. Now i am workin on a single 5" for flow reasons

Nice thing about doin single to rear axle then splittin into dual tailpipes is you can run 2 mufflers back there to quiet things down without hurting anything

So with 13 deg more duration and over .107" more lift, car changed characteristics at idle. Def more lope. Not to jack my own thread but I noticed what looked like two different exhaust approaches. I know the turbos change the game but on the first one it looked like maybe a typical 1 in 2 out setup and the second had a couple of resonators in the back. I'm wondering if you ran twin pipes to the rear or just Y in Y out. That had to be a wild routing either way. I have to do something with mine eventually but don't want to lose ground clearance on it. Suggestions? was lower but still enough for brakes. Idle speed wanted to be 950-1000 while other cam was ok at 850-900. But with converter stall being same, same gearing and etc, driving felt similar. Despite the big difference in head size and cam size, driving around felt similar. Heavier part throttle dare i say the big head combo felt more alive? Hard to measure since turbos kill performace when off boost. Turbine restriction just doesnt make a motor feel near as strong as you'd expect. So maybe there would be a driving difference if i ran no turbo and just headers?

Either way you should do everything you want below 6k rpm with a 236 and 195-210cc head. 88blackz51's build is pretty much what you need imo

 

https://www.thirdgen.org/forums/alte....html?styleid=

 

Are you using the OEM "dog bone" retainers or retro link bar type?

 

Here's what the combo is looking like.

Afr 210's 1050-8049 (75cc with 8019 spring pkg)

Comp cam QXI lobes- These are less aggressive than XFI but have a lot more lift.

Intake #13451 289A 237@050 158@200 .394L 1.6=.632L
Exhaust #13453 293A 241@050 162@200 .398L 1.6=.637L

The last decision is the LSA and ICL.

112 vs 110 LSA and advance. Comp recommended 112 with 2-3 advance.

112/110 would yield 67 overlap at adv/ 15 at 050, and a dynamic compression of 7.88.
valve events would be;

IO 34.5 EO 80.5
IC 74.5 EC 32.5

I believe the 112LSA is ok but think it may want a little more advance.

110/108 would yield 71 overlap. Would this make it any harder to tune? Any input?

 

I am old school from the 80s but with 421 CIs you could get away with 230 CC heads and 1 3/4 headers. Those are big block CIs and you should look at what a L78 396 came with in the 60s and they idled great, I know, I had one or two. A friend had a 67 vette 427 435HP three 2s and it idled good except 3 carbs are a nightmare. ORR89 and some of the other younger (engineers) will probably tell you that you are leaving some on the table even if wanting good street manners. It will be a torque monster though, my 406 makes over 500RWT with a mild solid roller, decent idle and 235CC track 1s. Very good problems to have. I almost forgot, I have a 9 bolt also and they are the strongest production rears made for our cars but after 6 months you will start hearing noises back there so expect to make a change there fairly soon as well. I went with a Ford 9 from www.autoweldchassis.com and couldn't be happier. Your going to make torque like a BBC. Back in the day if we were spinning too much out of the hole we would get the next bigger cam untill tire spin was controllable. So stupidly simple a problem solver where tire spin is concerned but it works perfectly.

 

Probably wont see much of a difference tuning wise, if you can tune the 112 the 110 wont be too much different. It will be lopey compared to the 112, but manageable

Seems like alot of lobe, not sure how they stack up in valve control vs something like xfi, as they are newer lobes. Be interesting to see how they work

I dont think it needs much advance, 2-3 deg sounds right.

 

Thanks for the feedback Orr. The QXI lobes are supposed to be stable as far as valve control goes. A tick less aggressive than the XFI's but as you noted, more lift. Somewhere between them and the XE high lift as far as ramp up. Do you think they are a good choice? I'm going to stick with the 112LSA for tuning and to move the torque curve up.

And Abray, you are right, I probably will leave some on the table. I too had a L78 375/396. Factory stock solid lift with those huge rectangular ports. Ran like a stout 350 up to about 4000 then it really came on. Your point about the cam/lower end torque is a good one. I am just a little out of my experience with tuning the EFI. I've done the "too much cam" route before and maybe I'm a little too conservative.

As far as the rear mine has the 9 bolt. It's been freshened up a couple years ago with bearings, rebuilt posi and girdle. But it will not handle too much abuse as you pointed out. I lean toward the 12 bolt but the 9" can't be beat either. It'll be the weak link and probably the last driveline item. The list goes on and on...

I need to finalize my specs so the builder can get the rest of the parts in route. If anyone has more input on the cam selection, now's the time!

 

IF comp says they are less aggressive than XFI then go for it. Its not necessary for your build, but certainly will help that motor breath with the heads and short duration. Just make sure you dont have to cut the base circle down too much to fit them in the long stroke motor. Those lobes probably are better on LSx cores or bbc cores. Other than that, you should make amazing power with such mild manners.

 

I will check that out. They didn't mention "having" to do a reduced base circle to fit the lobes but they can be cut on a .900-.950bc. I'm going with the link bar lifters so it doesn't have to fit the dog bones. And the builder believes it will all fit with a standard base cam. Callies rods are profiled for clearance too. But that is great input. Thanks man.

 

Yeah my cam is bigger and fits fine around the callies rods in mine. I just dont know what my base circle is probably .950-1.00"

 

We are in the same boat and you are probably close to my age or remember that era. I had a 66 SS Chevelle that was a 396 350HP but I turned it into a 475 horse monster. I listened to Van Halen 1 for the first time in that car when he first came out then the second Boston album almost a year later. I don't know anything about tuning either but I have a feeling we both need to learn REALLLL BADDDDD. I miss my 3 barrel holley. Dont forget about the rear end lesson I learned the hard way. 9 bolts are great but the old school rears still rule. We need to get ORR89roc to give us older guys a list of the stuff they use to tune so we can go to the websites and start teaching ourselves. These guys probably dont remember when there was only 3 channels on TV and remote controls were the closest kid to the ****.

 

I actually do remember manually operated black and white tv sets lol antennas too lol

Anyway be aware of oil pan to crank interference. May not have a problem with callies cranks but view Confuzed1's thread dart lil m 409 build. He had issues with stroker pans hitting crank.

 

One of the areas of concern for my build is the oil pan clearance both inside and chassis fitment. Going with one of the Milodon deep sump pans. Not a big kickout or anything but it does have some control baffles. I'm just as worried about it interfering with the exhaust crossover. May need some mods there.

As far as Van Halen1. Yeah when I hear some of the tunes on the radio my ear waits for the volume to go down for the track change lol. If you had some 6x9's and a clarion under dash graphic equalizer- you were big dog!

 

Yep, we were the remote

 

Thats an issue for sure, just about any aftermarket pan wasnt designed for the ypipe to go infront of the oil pan. Confused1 had that issue as well.

 

Hi. First things first before you buy any parts. To do a 421 correct you need the right rod to clear a standard base circle cam. You dont want a pencil cam as it gets unstable at high rpms with factory type lifters.Only one rod I know fits the shp block with no clearancing. Crower stroker rods and the billet units as well. Callies makes an xd rod but they are expensive as anything. If your going with an shp block then I assume you want to use the factory dogbones. With a bigger lift cam factory type lifters may hit the lobes. I had to go with crane units as they are for bigger lift cams. You can get away with 11.1 and ross makes the only off the shelf piston . In regards to lift numbers, the 8019s are only good to .650 lift. If you want a good street runner the 236/242 cam is excellent with a miniram. You may also want to think about the cam as well. Any cam you get, and if you use the crower stroker rods you can use a standard base circle cam, but at this level id seriously consider picking a cam then having that company have I cut on a billet core. Its an added expense but worth it. I see you putting this together yourself. If you need someone to do it I can refer you to someone who is doing mine amd it actually am expert in building these big inch strokers. Plus any parts you buy are below cost . Take care.

 

Well the block and RA are already here. It's a callies crank and rod set, not sure of the model but the rods are stroker clearanced. I understand they do clear a standard cam. The builder is a well respected company who supplies race engine across the country so I am confident in their ability. Their only short coming is that they don't typically spec street EFI type builds so that is why I look for so much input. Also, the 3rd gen chassis is outside of the typical race car requirements. The plan is to use the link bar type short travel lifter simply to avoid any retainer interferance issues. They are high $$ and so is a lot of this build. The bottom end will support a lot more than I am asking for. Thanks for the input and offer but this build is in good hands.

 

Ok . Just giving you a heads up. Most stroker rods will clear the block with some clearancing but almost all rods wont clear a normal base circle cam. Only the xd or crower ones do. 421 is a different animal all in itself. Absolutly no space. I just purchased a canton power pan. With that big a stroke you want as much control of windage as you can get. Im building one now. Check my thread on it.

https://www.thirdgen.org/forums/engi...cs-within.html

 

Thanks for the link. Awesome build. You have a bolder approach or are not looking for as much street-ability as I am. Candy A$$ is what my builder commented about my cam choice. lol. They wanted me to run a 254/260!

 

Ok here's the status as of June 22, 2014. All components are at the builder. The last major piece was the cam. I left the lobe selection to my builder/Comp cams but I think it is QXI lobes 236/242. I went with the AFR 210's and the small OD Pac springs (8019?) The only components left is the push rods since they will be selected when setting up the valve train. I took my 350 to their shop right before Christmas '13 so it has been over 6 months in the making. They were swamped with off season builds which gave me time to change the 383 plan to a Dart SHP based 421. The final decision was made at the end of March so needless to say it's been a test of patience for me. When I told them I was "in no hurry" I still thought I'd make ThirdGen Fest lol. Oh well I'm sure it'll be worth it in the end but I wish I could have started tuning before it got 95* with 90% humidity.

The plan is to take some pictures along the build and I will share them as well as the final-final specs when complete. A chassis dyno is also planned when I get a base tune down and I live less than 5 miles from a great 1/8mi track. All of this info will be posted as it becomes available.

 

Stumbled upon this thread. I sold my 421 recently that had 195 comp ports but it had too much low end. They were changed with 220's. Intake was a miniram and came was 236/242.

Go with the 220's my friend!

 

I was planning to go back with headers all buttoned up, bang on tune and an x-pipe. I was confident that the little heads would have made 450 rwhp/490rwtq.

The car was faster then a 520 rwhp GT500 after the FAST was cleaned up a tad more.

New owner has 220's and if all goes right he should be around 475 rwhp.

Area under the curve is what make these big small blocks kick ***!!

 

Just a fyi. Since you got some good money in the engine dont skimp on pushrods. .080 wall is ok. I went with a set from smith brothers .118 wall I think. AFRs your stuck with the 5/16 unless you machine the heads to fit bigger. They will go over your combo on the phone to get you what you need. A little insurance for your top end. You must be getting excited as your so close now. Im almost there too. What are you looking at exhaust wise? I have a practically brand new set of stainless works long tubes with the 2 1/2 collector and off raod pipe to connect to cat back I may go 3 inch because of the nitrous. Whats your fuel system look like? Take care

 

Yeah we went with thick wall Prods. Don't know the wall thickness.

It's in and running. So far it is exactly what I planned. Idles great @ 800 with 12" vacuum so all accessories are good. A/C cruise all work just fine.

Exhaust? That was a PITA but ended up with Hooker shorties, custom 2 1/2 mandrel bent straight back to the y pipe. Then 3 1/2 from there. Still have my Flowmaster dual outlet muffler for now. Sounds bad a$$! BTW sand blasted the headers and pipes, coated them with VHT ceramic paint and it's holding up great.

Have only been tuning cruise and idle so far. last WOT was @ 14:1 AFR (OOPS!) so I've got some work to do there. But it's still strong.

I can't wait to get her dialed in and to the dyno. Will keep you posted!

 

Awesome! I got my 427 (SHP block) running also. I just need a wide-band. I wonder if we will put down similar numbers.

 

Dunno I haven't been to the dyno yet. Still getting the tune down. Cruise is good and WOT richening up nicely. BTW ended up building a 414CI. Decided not to bore the new block, didn't seem worth it for 6CI. I really like this combination so far. Very streetable with the 236/242 cam it idles good. 12Hg vacuum @ 800RPM pulls from 1500 to 6000 pretty hard. It'll lug a little lower but not quite down to idle in high gear. I can't wait to get some numbers at the dyno and track. My goal is an honest 360WHP average from 4500-6000 (shift range) with a totally streetable package. It should hit ~400 at peak. I think I'm close. I figured 10lb per HP would make a nice driver.

Also, finished the exhaust with 3 1/2 over the axel and a Dynomax straight through round muffler. Man does this thing sound sweet. Maybe a tich loud at times but overall good. It's amazing how much force the exhaust coming out of the tail pipe has. I thought it was smoking but it was just blowing dust up!

 

Sounds great. What are you using for efi computer? I really think you are about 100hp short on your estimate. I feel you should def put down 450+ easy with a good efficent convertor. I know you have you exhaust all set but you may want to up at least the mid pipe to 4 inches. Im selling my stainless works long tubes and off road pipes because I feel this type of cubic inch needs a 3 inch collector min and 4 inch collector back for max power. Your wheel estimate is something the healthy smaller cubic inch motors would see. Your in a another league when you go 400inch plus. Crank should be at least 550hp min. What convertor are you runnin? I may have my vigilate 2800 up for sale. Looking to go with a triple disk so I can lock it up on the bottle.

 

I'm running stock 165 MAF computer with custom tuning and Wide band. As far as converter? Well it's a TKO 5 speed with Centerforce DF clutch lol. Yeah my power goal is minimal and I hope you're right with your estimates. My goal is a great running street motor. I'm not starry eyed on peak numbers- just a good wide power band. And when I say "honest" power, I mean in street trim, full exhaust and all accessories, Power steering, AC etc. Right now the one item which may hold me back a bit is the stock throttle body and MAF not to mention the factory intake ducting. Near future plans may include a 58mm throttle body and possibly EB flash if the MAF seems to be holding me back much. If I make my goal or better I'll probably leave it on the stock ecm. It's a hoot to drive as it is!

 

Looks like a great build you have there. Did you get it on the dyno yet?

 

Congratulations on the road based tuning! Sounds like the engine is running good.

I am in the same boat. Presently adjusting the engine dyno based tune for the street.

Best Regards,

Bruce

 

Haven't dyno yet but went to strip to do some tuning. Ran 8.1 on motor with easy launch. Speed was 89mph so pretty good on power. Should be around 390whp average power. There's more to be had I'm sure. Will update soon.

 

what are you running for a distributor?

 

Stock for 89 distributor & module with msd coil, cap and wires. I've considered running the msd dist but couldn't really understand what the advantage would be. May use a msd Box at some point. You?

 

I was trying to find what to use since my 86 dizzy wont fit. Thanks

 

Happy New Year!

I use an MSD Pro Billet distributor and Digital MSD-6A ignition box.

Not sure if the MSD distributor is worth any power?

Best Regards,

Bruce