anyone have a .513 lift cam and stock heads?

-
I think that much lift is on the VERY ragged edge of what stock heads can handle. I think you'll need to cut down the guides. I think you'll also want a stronger spring.
 
Lunati doesn't allways list there spring to go with there cam. OR maybe they don't have a spring for it. That is what I noticed from there web site at least.
 
Look on the lunati site and pull up the cam card. It should have the spring on the card.

I'd bet they recommend the double spring similar to the 995 comp spring.

Probably about $100 set. Another 40-50 for retainer and 20 or so for locks. Use 10* locks if at all possible. Better than the 7* pieces.

You're on the ragged edge for stock rockers. No chance stock springs work with that cam
 
With that much lift you'll want to step up to stronger springs i would think,the factory rockers i'm not a fan of them the ratios are usually off,i like having an adjustable valvetrain.if you can get some of the factory adjustables for cheap money you can go that route,or bite the bullit and get some nice roller rockers,as for that cam i'm running it in my 360 right now and i'm very happy with the results,only i'm running Edelbrock heads..But i've used 3 different voodoo cams all with great results...
 
You will need to upgrade the springs, possibly as said to doubles that require the guide work and spring seats to be cut. I would not run factory stamped rockers with a double spring. Go sintered iron for the bare bones budget approach.
 
You could use the 273 adjustables.

I have a set, $100 plus shipping

If you know what length pushrods you need, I may have a set. The adjustables like the stock 273 pieces use a different PR ends (cup/ball)than the stamped steel rockers (ball/ball).
 
If the cams hydraulic mopar performance has rockers that fit stock shafts that are beefed up in the pushrod cup and the pivot area
 
doofsduster70 said:
can i get those from say sealed power? what year 273 did the come in ?
Click to expand...


I don't believe they are available from anyone anymore. Look up a 65-66 273 with Mechanical camshaft. Crane and MP units are in the 275-300 range for new ductile iron set ups.

The MP units will start popping with the double springs. It's the ragged edge.
 
I havent fired it up just yet,but it really isnt too big of a cam.It has less duration at .050 lift than the mopar 509,and the intake lift is only .494,so i dont see any problems with clearnace issues.I did order edelbrock torker valv springs,so i wouldnt need the extra machine work.They are single with a damper,and the specs are close to the same as what lunati calls for.Oh,and they were only 69.00 compared to the lunatis 110.00 at the time i purchased them. http://store.summitracing.com/partdetail.asp?autofilter=1&part=EDL-5777&N=700+0&autoview=sku Oh,im using my factory non adjustable rockers until i get some better roller rockers or something,and i dont forsee any problems with them.
 
I measured a set of 73 340 heads, casting 587. They wouldn't allow for more than .480 lift when the retainer hit the valve stem seal.
 
You can always use a checker valve spring with the retainer you plan to run and measure the travel you have until the retainer touches the valve guide. If you subtract the minimum allowable clearance required between the guide and retainer at full lift from the total travel distance, this will give you the max allowable lift with your combination of parts. I would check a few valves to make sure the machining is constant. You will likely be very close to the limit. If you machine the guides now you will be able to swap to higher lift cams later without pulling the heads. I believe you can also use a better quality valve seal. Something to think about.

Use adjustable rockers to avoid the pushrod breaking the rocker. It has happened to me as well.
 
You must log in or register to reply here.
-

Back
Top