Thoughts on my CAM selection for my 400ci Engine Build
 

Hi everyone, I'm new to this site and was hoping I can get some feedback on my engine build. I'm mostly looking for some feedback or possible suggestions for my CAM.

I'm going with '68 #16 heads 2.11/1.77 valve heads (75cc) and trying to bring my compression ration down around 9.3:1 so I can run pump gas (91/93 octane)

1966 Pontiac GTO
-‘73 400 ci block going to be bored out 0.30 over from 4.12 to 4.15
-Tri Power Carbs being put together by Pontiac Tripower
-‘68 #16 heads 2.11/1.77 valve heads (75cc)
-14cc dish pistons
-Ram Air Exhaust Manifolds
-2.5" Exhaust with Flowmasters
-4 Speed Muncie M20

I decided to stick with a hydraulic flat tappet cam and have been recomended Crower 60919 Hydraulic Flat Tappet Cam (Duration: Int/ Exh 304/316, Duration @.050” Lift: Int Exh 231/240, Lobe Lift: Int/Exh .313/.313)

I was advised this setup would get me around the 360-375 HP range.

I've read this is a good CAM for a 455 or stroker and wondering if it will work for my setup while trying to achieve the 9.3:1 compression.

Any feedback is greatly appreciated.

Thank yoiu in advance

What do you have for rear gear ratio?

Note that in the high comp era that factory cams with durations like that your Looking at with that Crower where not used with less then 10.5 to 1 true compression and with a minimum of 3.90’rear gears.

Keep in mind that it’s far better to be under Cam’ed then over Cam’ed in terms of average street performance as long as the amount of cylinder pressure does not make for ping or knock conditions.

The average 68 to 70 400 motor rated at 350 hp had a true 9.5 compression and used the factory 067 Cam which had 197/212 @ ,050” with only .407” lift, and on top of that exhaled thru log type manifolds.

If you want to run that Crower cam with a compression ratio that will work with 91 octane and not have a car that’s a Dog below 3500 rpm then you want to run Rhoads lifters to off set that!

To end up with your goal of a 9.3 compression with your 406 cid motor you will need a total of 100 CCs when your piston is at TDC.

75 CCs of chamber volume plus a 14 cc dish gets you to 89 CCs.
Now add 9.4 CCs for a Fel Pro 1016 head gasket and your at 98.4 CCs.

Add another 4. 43 CCs of a deck clearance of .020” and your at a total of 102.8CCs.

Now lastly add in 1.2 CCs for compression ring land volume and your at 103.8 CCs total.

Looks like your 3.8 CCs over where you need to be if your heads do CC out to 75.

To get to your dead on target compression of 9.3 you will need to mill the heads .022 or get pistons made with only a dish of 10.2 CCs.

Hi Steve, unfortunately I haven’t checked my rear gear ratio and have no idea what my gears are in tranny. As of right now all I know it’s a 4 speed Muncie M20. I’ll check on the rear gear ratio when I get home.

Thank you


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That cam is not a good choice for your combination.

This is what Butler had recommended to me for my build which is very closely matched to yours, 14cc dish, 9.5cr with Manual Trans, 3.55 gears. G70-14 tire size.

“This is a very nice street cam. great power and sound (the most we’d run with a 400, power brakes, etc):”

https://butlerperformance.com/i-3164...tegory:1234796

master kit:

https://butlerperformance.com/i-3164...tegory:1234796


Butler Performance
2786 Hwy 43 North
Lawrenceburg, TN 38464
Toll Free # 866-762-7527
Email: info@butlerperformance.com
www.butlerperformance.com

I run a ram air iv style cam like that 60919 Crower in a 400 with 16 heads and right at 10:1 compression. I agree with Paul. It would likely be a little much with lower compression. With 10:1 compression, 3:55 gears and an M20 4 speed, it runs pretty hard. It really could use 3:90-4:10 gears, though. I don't think I would go bigger than something like a 2802 summit cam (224/234 .465 .488 114).

The cam in your link is quite different from the cam the OP is inquiring about.... Wrong link?

I just finished a similar build and had it dyno'd, so I can show you what I did.

-400 +.030
-#13 heads with mild port work on intake only. CC'd at 77cc's.
-Icon flat top pistons
-Zero decked block
-Compression ratio ended up being exactly 10:1
-Crower 60243 cam (228/235). This is the next size smaller Crower cam then the one you are considering.
-Rhodes V-Pro lifters
-Performer RPM intake
-Pro System 4150-style carb
-1.5:1 roller rockers
-RARE long branch manifolds

It made 394 HP at 5700rpm. I do not know what the peak torque was because he didn't pull it below 4000rpm on the dyno. It probably would have made 25-30 more HP with long tube headers. I had the RAIV cam in the engine before and did not like it (same as the 60919 you are considering)

I'd go with a Voodoo 703 or Ultradyne that is close.

http://forums.maxperformanceinc.com/...d.php?t=817331

https://www.lunatipower.com/voodoo-h...8-268-276.html

Advertised Duration (Int/Exh): 268/276
Duration @ .050 (Int/Exh): 227/233
Gross Valve Lift (Int/Exh): .489/.504
LSA/ICL: 110/106

i think you’ll be happiest in the low 220 range on the intake @ .050. have you run the numbers on a dynamic compression calculator?

The Lunati VooDoo 703 would work great in your 400 installed at 104° Intake Centerline. The Crower 60919 RA IV copy is a great cam in a 9.5 to 10-1 compression 455+ engine, but way too much camshaft for a 400 unless it has 11 to 11.5-1 compression. The camshaft that Butler recommended RWFisher is not even close to the same camshaft as the 60919, even though they appear similar at .050". The Butler camshaft has waaayy less seat duration than the Crower 60919.

This cam^^

Just so everyone will know, Lunati is out of flat tappet Pontiac cam cores again. They have a few of their standard grind cams still on the shelf but nothing in stock to grind custom specs. I have two on order for customer's engines as we speak and they have no ETA.

Attachment 578524

This is the UD cam I use in my 400, seems lively everywhere and pulls off idle through 5500. Idle is a little smoother than I wanted. The butler cam seems similar with a little less lift but more .050 seat time. Does anyone have the cam card for that butler cam?

I have sold quite a few Wolverine (Camshaft Machine Company) 744 High lift camshafts
for 400 cid engines and they have a nice noticeable idle and run well to 5500 rpm.

I no longer sell camshafts but I believe those cams are still being made with slight changes to them. 224/236 at .050 and about .480 lift.


Tom V.

The Butler HFT cam linked in post #5 above is made up of Comp XE lobes number 5445 & 5208 shown on page 14 in the link below.
These lobes are custom ordered by Butler with a 112 Lobe separation.

https://www.compcams.com/lobe-catalog


( Information provided in this post does not represent any endorsement for the cam. And unless specified it is not based on personal experience and is offered for general interest only )

.

There's always a better cam !
I like the 60423. A good compromise between the 224 and 231 cams.

Thank you everyone for the replies.
I just got back from a trip and found out my gear ratio to be 2:56. Based on my engine build do you still think a cam’s such as a crower 60243 or Voodoo 703 would work?

Thank you

Let me put it to you this way, once the factory got forced into the emission and Cat era and those crappy gear ratios, when you look at the 400 4bbl motors, none of them used anything larger then the 066 factory Cam!

Granted these motors I mention had less compression then you will have, but that compression gain is not enough to make up for those lazy 2.56 gears!

You have to get up to at least 3.23 gears, and 3.42 or 3.55 would be a whole lot better even if you want my 2 cents!

Also 400s love to rev, so if your putting good Rods into your build to do that don't neuter them by having to stuffing in a Cam that can barely make it to 5200 rpm and has already nosed over hp wise by 4500 rpm!

This is yet another reason for getting the rear gear ratio up!

man the wolverine cams were nice pieces back in the day
i did not know they were around anymore