Looking for a cam recommendation mostly stock 73 455 w/ 4 speed
 

Hey folks,

I'm looking for a cam recommendation for my 1973 455 rebuild. The engine is numbers matching to my 1 973 Brewster Green TA I'm restoring with the original four speed.

The engine is at the machine shop now and will have to be bored .030. Other than resurfacing the heads and decking block the engine will be stock. So around 9:1 CR most likely.

I was considering a HR for reliability sake but after a lot of research I've deemed it unnecessary to spend an extra $2,000 on one. Mostly because I want to keep the car as close to factory as possible and I think a good HFT broken in properly will be fine.

Cam choices are all over the place so I need some help!

My car came with the 067 cam and I'd like a little more. But streetability and reliability are most important!

I'm looking at the Summit 2802 or 068. From my research summit cores are made by CMC in Michigan. But if anyone has a more reliable brand to recommend let me know!

Thanks!

I like that Cam with the lift that it has
for a motor of your cid with a 4 speed, but you will need to mill your heads some .045" to get to there recomened 9.5 Comp.

This Cams Exh lift will require different springs and the cutting down of the tops of your heads valves guides to have the retainer to seal clearance to run at least .500" lift.

This machine work should be done anyway so you can run positive type guide mounted valve seals.

With any Cam you choose to go with be sure to step up to full 7/16" rocker studs and poly locks to make the adjustment.

Those 4X heads have been known to crack so on the deck surface be sure to roll over all and any sharp edeges even if you do not mill the heads any take the needed time to do this.

With any Cam but a stocker you need to check your valve geometry.

This is not only to set the valvetrain up for minimum ware, but to actually get the amount of valve lift and performance out of the Cam that you payed for.

If your heads need to have a valve job done then spending another 120 bucks on new 1.77" Exh valves will kick up the compression some and then you will only need to pay for a mill of .035" instead of .045".

This will also increase low lift flow which with Exh Manifolds is the best way to go since log type Exh Manifolds are pretty restrictive , and better low lift flow takes advantage of using the Exh runner area that you do have at a time when it's not saturated with Exh gasses .

If the 4x heads are original 455 heads then you cant get 9.5 comp with a .045 cut using flat top pistons. Those heads are like 114cc to start with.

9:1? I’d recommend the Lunati Voodoo 702.

Advertised Duration (Int/Exh): 262/268
Duration @ .050 (Int/Exh): 219/227
Gross Valve Lift (Int/Exh): .468/.489
LSA/ICL: 112/108
Valve Lash (Int/Exh): Hyd/Hyd
RPM Range: 1300-5500

Summit 2802 is my choice.

Your ’73 D-port 455 with the modifications to the heads the Steved25 recommends will probably net you closer to 8.4 to 1 static compression with .040” quench distance if you ‘zero’ deck the block and use Felpro 1016 head gaskets (.039” compressed thickness). On my 455HO engine the 191 heads were cut for 108 cc chambers and with ‘zero’ deck/1016 gaskets, had only 8.6 to 1 static compression. I’m not sure how much you’d have to cut your 4X heads with 125 cc (?) chambers (7.6 to 1 compression stock factory rating), but make sure your intake ports align properly, or you may have to cut it as well to match the head ports. The 455HO engine has the Summit 2802 cam and it made good power on the dyno (425 hp/530 lbft. torque). The same short block was under a ’70 YH 455 with small valve #15 heads (1.96”/1.66” from a std. ’70 455 B-body) and log manifolds. In this configuration it made 390 hp/512 lbft. torque with 9.95 to 1 static compression and was all done by 4800 rpm. The 068 cam would make 35 hp/45 lbft. less than the 455HO and the 50 hp/60 lbft. less than with the small valve head 455 from previous 455HO/455 D-port dyno experience.

Your 4X headed 455 (462 at + .030 over) will most likely be in the 400 hp/500 lbft. range with the 2802 cam and larger exhaust valves with the 2802 cam and a lighter forged reciprocating assembly with the log manifolds (and 2.5" mandrel bent headpipes).

I attached both 'best' dyno sheets for comparison.

Dennis

6X/4 heads for 93-97 CC. chambers, screw in studs, hardened seats, with basic clean up in ports / bowls, 2802 cam couple degrees advanced
easy peasy still very close to bone stock manners but much more when secondaries kick in

I am in the process of doing the exact same thing to my Brewster 73 D-port auto.

I am going roller. I did the Eagle/Mahle 4.25 stoke kit. I am staying 100% numbers matching on the outside. That being said I also wanted a stock idle. I works with Lee Atkinson to design a cam.

My heads came in at 111cc’s and the pistons measured a 7cc dish. I went 4.185 bore

I’m at 8.6:1

I attached my cam card.

I had additional criteria to run my lifter dog bone setup to dramatically reduce the roller setup cost.

Stan

Stan,

Did you use the Ford dog bones and LS lifters? If so. How thin did you have to clearance them?

You could also use 4X heads with a secondary stamp of 3 or 7 which are big valve/101 cc if you wanted to keep the stock looking heads with the correct head code.

Ponchjoe,

I am making custom dog bones to eliminate the ford parts. Working on eliminating the spider also.

https://forums.maxperformanceinc.com...d.php?t=847708

Read the newest posts above.

Stan

What a timely post. My new to me car has a car show cam. Its aweful to drive as it causes the engine to chug, buck, and just run shixxy in first in 25 mph neighborhoods. Soot over the back of the car etc. But when you hammer it , it gets rubber in 3 of the 4 gears. Seller said Lunati 10704. The OP has almost the same combo as mine except I have 4X 7h heads with 1.77 exhaust valves, RA 3 style manifolds, Pypes duals and 3:42 gears. I never took the Summit 2802 as a real solution until I read this thread, but am considering one for now. FWIW, this is a good engine that keeps the car going down the road until I decide on a forever engine. I aint getting any younger....

Twister I don't think your motor meets the 9.5 minimum compression recommendation that Lunati states is needed with that Cam .

Your 4X heads have hopefully been set up for that Cams amount of valve lift.
Also very darn helpful with Cams like this ( especially with not enough compression!) is to set up your HEI in this way that Jim Hands found works out the best.

With stock 4X 455 heads you aren't going to make enough compression for much of a camshaft upgrade. Decked/squared and tight quench with a decent cut on the heads I'd go with an 068 camshaft and top it with USA made lifters. Use stock springs, stock retainers, keeps and stock stamped steel rocker arms. Keeping the weight down above the lifters is a critical if you want it to live for a long time.

Folks use WAY too much spring pressure on these engines plus heavy parts combined with off-shore lifters so we see a lot of problems with camshaft lobe failures, all easily avoided by using better parts and stock spring loads. There is NEVER any need to spin a mild 455 build high enough you need 120-160lbs seat pressure and 350-400lbs over the nose spring pressure, but I see it done with nearly ever build someone posts about.

I've been publically critisized many times for running a LOT less spring pressure than most others, but guess what? ZERO issues with cams going flat or any other problems in that area. I'm also NOT a big fan of any of these aftermarket roller rocker arms, unless you step-up and buy good USA made stuff. All you do with most of them is introduce a LOT of failure points and I've seen enough of these roller tip and full roller junk rockers grind up over the years to avoid all of them.

Same with timing sets. Everyone jumps all over these "double roller" sets like a dog on a steak bone, then cheaps out and buys cast iron sprockets with 3 keyways. They are about 10 percent as strong as a good Cloyes factory set and woln't last for chit in long term service. If you go that route at least get a Cloyes with an IWIS chain so you sleep a little better at night. Here I just source NOS factory sets off Ebay and I sleep really good because I know they will go at least 100,000 miles and I can go on to worry about other things.

Anyhow, the 068 gets my vote and they are still available at the moment USA made from Melling. Rumor is that ALL of the USA made flat cams are going bye-bye, so you might not want to wait too long to get one in your hands. Same with lifters. They are going to disappear soon as well. I'm in the middle of two engine builds here and having one hell of a time finding USA made parts to put them together with.......FWIW.......

Thanks for all the recs I’ll prob stick with a 068 cam.

Based upon my own low compression stock-head 455 in a '73 Trans Am (clone), I'd suggest the 744 cam, if you can find one. I think Butler may still have some.

My cam isn't a 744, but it is somewhat close. Dyno chart attached, from a DynoJet chassis dyno (wheel HP/TQ), and the run was done on 87 octane.



I sent you a message.

Lee Atkinson

Just an update I've decided to go with a full roller cam for reliability sake.

Butler recommended this cam it's similar to the RAIV but it seems TOO big for my CR.

https://butlerperformance.com/i-3164...%3Fq%3Dbp802xx

I'm leaning toward this one instead on a 112LSA.

https://butlerperformance.com/i-3164...tegory:1459685

Thoughts? I'll be running a 1.6 roller rocker as well.

I would do the milder roller cam you posted which is similar to the RAIII 744 / 455 SD 323 cam.

Or go with a cam Lee recommended.

Ain’t nothing wrong with the 068 with 1.6 rockers either if you don’t go roller.

068 if all you want to do is a cam change.....
Low lift cam so springs are not needed......
If heads are coming off , to raise compression, then look to a Custom Cam