Gimme your cam opinions for 273 ASAP

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4spdragtop

4spdragtop

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Ok, I had started another thread where Dad and I were into his 273 and we are going to change cam/lifters timing chain and gears. Heres some info on the engine. It is/was a 273 4bbl commando. Date code on the block is 5 6 66. All the internals of his original commando engine were put into this engine. Everything EXCEPT the pistons. The prev owner if I remember correctly said we are probably running around 9, maybe 9.5:1 compression as the new pistons arent dometop. I phoned 3 companies today and here is there recommendations for solid cam and lifters

Comp cams. " go with magnum 270s. Entire kit with timing chain/gears is # SK 20-246-4 Price is $335.00. This is the only option due to the compression that dad is running and we will have to go with 2000 rpm stall"

Isky cams " E4 grind, and cam is #390144, lifters #3102H $320" NO timing chain and gears, that has to be bought elsewhere.

Edelbrock, NADA, they dont have any cams for the 273.

The reason we are limited with cam choices is due to the current compression, as well as the stall, we have an option of the factory orginal..which I believe is 1200 RPM, or another one which I believe is 2000 RPM. Dad doesnt want a race car, plus we dont want to get into changing pistions right now. He wants to have it on the road in a month or so. What does everyone think?? Oh plus if we go with Comp Cams they only ship UPS and most of you know what I think about them SOB's!!

Here is the link to the other thread I started
http://www.forabodiesonly.com/mopar/showthread.php?t=179525

Thanks for the input!

4spdragtop
 
The Isky E-4 is probably as close to the original factory 4BBL cam as you will find.
 
4spdragtop said:
Comp cams. " go with magnum 270s. Entire kit with timing chain/gears is # SK 20-246-4 Price is $335.00. This is the only option due to the compression that dad is running and we will have to go with 2000 rpm stall"
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I will say this about the comp kit, the timing chain that comes with it is not a double roller unless they have changed things up. I bought the cam kit for my car and had to order a new chain and sprockets, becuase I wanted a double roller.

Might be worth asking about.
 
You've GOTTA have solids??.....you could change the pushrods, keep the adjustable rockers and open up a lot more choices on cams.
 
grimreaper said:
The Isky E-4 is probably as close to the original factory 4BBL cam as you will find.
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That's what I found too. I like my E-4 but it doesn't have much lope if that's what you want.

Oldschoolcuda said:
Personally have 20-246-4 solid comp cam you listed in my valiant & love it.Understand shipping issue & since you are going solid route here is another option. FBO will grind a cam for you to racer brown specs. Here is website with specs listed.

http://www.4secondsflat.com/Racer_Brown_Cam_Specs.html

Oldschoolcuda
Click to expand...
Do you have a video of your car/ I'd love to hear that cam.

Here's mine. Sorry for the poor video.
[ame="http://www.youtube.com/watch?v=v555B5_uBJ4"]HP273- Isky E4- Accurate LTD exhaust - YouTube[/ame]
 
You can use the 273 adjustable rockers but will need special length pushrods as the plunger is higher in the lifter with hydraulics.

A second voice on the Comp timing chain. I got a Comp kit and could not bring myself to using the supplied chain....had to go down to NAPA and get one spec'd for a 340 to be satisfied.
 
I phoned a local speed shop here, his recommendation as far as comp cams and going hydraulic is to go with comp cams XE268H. Dad and I dont really know which way to go??? Stick with the solids or go hydraulic??:banghead:
 
Screw it all, how about a full roller setup (cam, lifters and rockers)!
 
I stick with my original recommendation.
 
4spdragtop said:
I phoned a local speed shop here, his recommendation as far as comp cams and going hydraulic is to go with comp cams XE268H. Dad and I dont really know which way to go??? Stick with the solids or go hydraulic??:banghead:
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I think that would be a little big. Remember, hydraulics that are similar in grind to solids are always "bigger" by virtue of the valve lash on a solid helping to lose about 10* of cam timing. Again, it sounds like the little 268 solid would be perfect. Why are you beatin your head against the wall? The decision isn't difficult. Simply use a little solid cam like the engine came with and it will run great. The 268S is light years away from the original grind and will be a big improvement too.
 
Steve if he's going this far why not go to Kantor and get the dome tops, put the original block back together with an original equivalent cam and make that thing run like it did when it was new. Then he would have a nice ride with decent power and numbers matching everything.
 
Exactly Stroker. No sense in over engineering the build. There is no perfect cam but for this application there are a few good choices. If you stay with a solid cam nothing changes but the cam and lifters (and a timing chain and gears if needed). If you want a hydraulic you will need different pushrods in addition to the cam and lifters. Keep it simple with a driver car where optimum performance isn't an issue. tmm
 
StrokerScamp said:
I think that would be a little big. Remember, hydraulics that are similar in grind to solids are always "bigger" by virtue of the valve lash on a solid helping to lose about 10* of cam timing. Again, it sounds like the little 268 solid would be perfect. Why are you beatin your head against the wall? The decision isn't difficult. Simply use a little solid cam like the engine came with and it will run great. The 268S is light years away from the original grind and will be a big improvement too.
Click to expand...

Hey Rob, I just flipped thru their online catalog and I cant find the 268S?? And I just noticed there is a note with the comp kit that you cant use the stock springs.....here is where I bang my head:banghead:
 
Erson - E420305 ; Comp - 20-246-4 (Magnum 270s) if you have headers or 20-233-4 (XE268S) if you don't
 
None of these should use stock springs. But, they all can use the Comp 901-16 perforamnce spring... That's a drop on part.
 
4spdragtop said:
Hey Rob, I just flipped thru their online catalog and I cant find the 268S?? And I just noticed there is a note with the comp kit that you cant use the stock springs.....here is where I bang my head:banghead:
Click to expand...

I wouldn't reuse the springs you have anyway. Here is the cam.

http://www.compcams.com/Company/CC/cam-specs/Details.aspx?csid=669&sb=2

Simple for the springs. Simply find one that fits with no mods (single spring with damper) that has about the same seat and open pressures as the dual spring. You're not going racing so you don't need a dual spring. I would bet the Comp 901-16 would work fine. There's always a way. I have run the 901 spring before on a small solid with good results. Them springs don't know what kinda cam they're on top of.
 
I should have mentioned the valve springs. It's always a good idea to use the recommended springs for the cam you use. The original springs are 25+ years old
and should be freshened up with new. tmm
 
As someone else (I think sireland) said in the other thread, I wonder what the rest of the engine looks like? I mean.....not wishing you an omen, but if you're going in as far as a cam change........
 
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