273/ 2 barrel camshaft options

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AJ/FormS said:
Just so you know;
a 273 is just the equivalent of a big-bore 318.
So, anything off a 318 , except the piston assemblies, will swap over.
Except the 65 and older heads, sorta need the matching bolt-angle intake. So then;
if you intend to put a 4bbl on it, at some time in the future, IMO, I would start with 1966>69 closed chamber heads. If you go with the open chambers and a bigger cam, then the cylinder pressure will fall way too low to be fun.

as for cams;
> on a low compression engine, with an automatic, if you install a lopey cam, you will be sorry, see Post 13, above.
> if you change the cam, I highly recommend to tighten up the LSA(Lobe Separation Angle) in an effort to keep the cylinder pressure up.
> IIRC, the factory gasket was 020 thick, with an appropriately-sized borehole. Those are no longer available, off-the-shelf.. the closest available is 028, and the bore-hole is huge. the new gasket is thus 6.3 compared to about 3.5cc/atock.
This one single change will drop a true 8/1Scr 273 to 7.76 and the pressure is expected to drop to 130, from 136psi. It may not sound like much, but that is the same as installing a cam of 8* more intake duration, which is more than two cam sizes bigger. Bad trade-off.
Closing up the LSA from the factory 112* to 108, with no other changes, on the 7.76SCR engine, is predicted to jump the pressure back up, to 133 Good Deal. and the bonus is better fuel-economy. Now, if you advance this cam to in at 102, this will reduce your Powerstroke back to what you now have, but increase your pressure to 134, over the factory, 129(with the 028 gasket). This is another good deal.
The point I am trying to make is this;
the factory 2bbl cylinder pressure is already extremely low. and it's only gonna get lower after the gasket swap. That's bad. Adding a bigger cam with a later-closing intake event, is gonna drop the pressure even lower.
If your engine needs pistons anyway, and you need a cam
now is the time to pump the compression ratio up, and neatly get around the problems.

As an example, building to a true 9.5 Scr, will allow you to slide a cam in there of about 10 degree later Ica(intake Closing Angle) and the pressure might jump to 161psi. Excellent deal.
Ten degrees is about equal to 4 sizes, going from a 112Lsa to a 108. That's a lot.
and, on a 108LSA, the compression /power degrees end up about the same as you have now, But the overlap jumps to 46 from 28. If you put headers on that, those extra 18* will make a nice little power bulge starting in the midrange. and the pressure increase will make the bottom-end feel about 22% stronger.
Again, the point is this, careful selection of parts at this stage, can make or break the combo.

Putting that same bigger cam into a 7.75 Scr engine is predicted to lower the pressure to 117psi, and the engine will feel about 15% LESS powerful, on the bottom, as it does when stock.
That's a bad trade! This will require a much higher stall convertor, and likely, a deeper rear gear, just to get moving as it once did.
and/but
46* of overlap is about what the 340s had, so, not much of a lope to it, but maybe enough to satisfy your hunger, lol.

Oh and to answer your question about the cam lobes falling into the pan, yes, that is a possibility. In my case, I was willing to take that chance.
The post you are referencing, was about what I did.
As stated, your results may vary.
"My first thoughts wouldn’t this just continue to break down quickly and send shrapnel through the system into the block and bearings and so on?"

Several decades later, I did lose a cam that way.
However, I run very little preload on my hydraulic lifters, and the ticking began almost right after an oilchange. This was back in about 2004 when the oil companies took the zinc out of the oil, and failed to send me a memo.
Anyway , I figured it out pretty quick, slammed a new cam into it, changed the oil and filter again, added a bunch of supplement, and hoped for the best.
The following winter, I took the engine down, cleaned it out, made some compression/spring changes, and slammed it all back together.
Back then, my car was a DD, so every fall, I took the 360 out for freshening, and swapped in a 318 for the winter; sometimes with an automatic, and sometimes with a manual, sometimes with an overdrive, whatever I was planning to run the following summer. and I changed the rear end ratios around pretty regularly as well. By 2005 or 2006, my kids had all grown up and moved away, so I bought another DD, and the 360 has been under the hood ever since........ with no more cam-trouble.
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I corrected a couple numbers at the start of your post.
 
AJ/FormS said:
If you look in the old Mopar Performance catalog, you can see the .008 advertised numbers, compared to the 050 numbers.
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But how many of us have one of those catalogs. Really, other than having that information available for those like yourself, It doesn't matter to 99% of the general public. :poke: :lol:
 
Bewy said:
The cam in post #14 is quite small, may not have have as much 'oomph' as the original cam. That is because solid lifter cams with 018" lash are equivalent to about a hyd cam 9* shorter at 050. So equivalent to a 189 @ 050 hyd cam; equivalent meaning, gives equivalent performance.
Also, using a re-ground cam might lead to lash adjustment problems because the base circle of the cam is reduced in size; consequently, lifters sit lower & rocker adjustment screw needs to be screwed in further to get the correct lash. Ok if there is enough thread on the adjuster.....

I agree with others that the Isky E-4 cam is best. Isky cams are good. If you do not want lifter/lobe failure, have your old lifters re-faced; they look in reasonable condition. Do not buy new lifters, they fail.
NEVER, EVER USE USED LIFTERS ON A NEW CAM....NO MATTER HOW GOOD THEY LOOK.
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Hello and good morning, thanks for taking the time to participate here, until I hear from the machine shop on the block and heads I’m at a standstill. But I am leaning into the option of the isky vs grinding the existing cam for the exact details that you mentioned.
Bewy said:
The cam in post #14 is quite small, may not have have as much 'oomph' as the original cam. That is because solid lifter cams with 018" lash are equivalent to about a hyd cam 9* shorter at 050. So equivalent to a 189 @ 050 hyd cam; equivalent meaning, gives equivalent performance.
Also, using a re-ground cam might lead to lash adjustment problems because the base circle of the cam is reduced in size; consequently, lifters sit lower & rocker adjustment screw needs to be screwed in further to get the correct lash. Ok if there is enough thread on the adjuster.....

I agree with others that the Isky E-4 cam is best. Isky cams are good. If you do not want lifter/lobe failure, have your old lifters re-faced; they look in reasonable condition. Do not buy new lifters, they fail.
NEVER, EVER USE USED LIFTERS ON A NEW CAM....NO MATTER HOW GOOD THEY LOOK.
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Hello and thank you for taking the time to share some very useful info. Until I hear from the shop on the condition of the block and the heads, I’m at a standstill. The isky does seem to be the ideal solution, but as member 4spdragtop had commented, would this fall into “over cam” too much for the simple 2 barrel 273 to handle? What else would I need to do and or change in going with the isky?

Am I understanding that it would be as simple as having my existing lifters refaced and then just installing the isky cam? Will I need to replace springs, push rods and or valves?

This setup would perform ideally to factory specs of what the engine has been its whole life if not better?

Does anything need to change with the timing, cam or crank gears or chain?

I apologize for my stupidity here and for the 21 questions. Thank you again for your time!
 
Bottom line is, if you want to order an off the shelf solid lifter cam for your mild 273, the E 4 will work fine. If you want something smaller, you will need to have one custom made. No real issue, just another step to take. Will your engine know the difference? Probably not enough to notice. I advanced mine a few degrees and it has good power throughout the range. It is topped out at about 5,000 but there's no need to twist it any higher.
 
toolmanmike said:
Bottom line is, if you want to order an off the shelf solid lifter cam for your mild 273, the E 4 will work fine. If you want something smaller, you will need to have one custom made. No real issue, just another step to take. Will your engine know the difference? Probably not enough to notice. I advanced mine a few degrees and it has good power throughout the range. It is topped out at about 5,000 but there's no need to twist it any higher.
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Hey there, after some further digging, I see that you crossed this bridge back in 2016 so I hope I haven’t worn you and the community out with a rinse and repeat of the topic.

Would you be willing to educate me further on the process of installing the isky cam?

Have the machine shop install the cam bearings and the isky E-4 cam.

(No machine work of any kind is being done at this time, just thorough cleaning and reassembling)

Reface and use my existing lifters.

Any other parts that need to be replaced and or adjusted in doing this install?

This setup won’t hurt and or “over cam” the remaining components in the engine?
As of right now, EVERYTHING is going right back in where it was after cleaning. The only parts being replaced will be bearings and gaskets as far as block related items, as of now.

Again this will be a basic daily driver on weekends and the occasional cruise.

I appreciate your patience! Thank you!
 
coast2coastkidd85 said:
Hey there, after some further digging, I see that you crossed this bridge back in 2016 so I hope I haven’t worn you and the community out with a rinse and repeat of the topic.

Would you be willing to educate me further on the process of installing the isky cam?

Have the machine shop install the cam bearings and the isky E-4 cam.

(No machine work of any kind is being done at this time, just thorough cleaning and reassembling)

Reface and use my existing lifters.

Any other parts that need to be replaced and or adjusted in doing this install?

This setup won’t hurt and or “over cam” the remaining components in the engine?
As of right now, EVERYTHING is going right back in where it was after cleaning. The only parts being replaced will be bearings and gaskets as far as block related items, as of now.

Again this will be a basic daily driver on weekends and the occasional cruise.

I appreciate your patience! Thank you!
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If you have never built an engine before you should "read until your eyes bleed" on the subject. You will need the knowledge to do it right. Or, just have the machine shop assemble it for you. You can have the lifters refaced as long as they are good to start with and the shop that does it does the work properly. A good double roller timing set is needed and there are many threads about that subject here. You should degree the cam in to make sure all is perfect there. That procedure is something you will need to study and understand before you do it. You will also need to buy, borrow, or rent a degree wheel and a dial indicator. You can just install it marks up but not knowing if it's right or not. SOmething else the machine shop can do for you. If you want to do this to learn and may be build some engines in the future, study up before attempting any of it. If you just want to frshen up the engine for your cruiser, You might just want the shop to do it for you.
 
I agree the E4 cam is a good choice for an off the shelf cam. I wouldn't go any higher than low 4's in lift because as mentioned, you can overcam that engine easily since you seem to be trying to keep it fairly stock. I'm a solid cam guy for my toys, so, I personally would keep that. If you can get those lifters refaced without losing any hardening, I would probably do that too unless you can find some quality new lifters out there. Maybe contact Esky for their opinion? Don't get carried away with heavy springs on a street car. You'll still want some good zinc oil regardless to keep the lobes happy. If you never done it, have your machine shop install and degree the cam along with a good quality double roller timing set.
 
As the vaaast majority have indicated, myself included, the E-4 cam would be an ideal choice.
Manufacturers produced engines with different ratings; high output, or high performance versions, 2bbl & 4bbl etc. So the E-4 would be a nice step up, with no problems.
Majority of lifter/lobe failures in recent years is from poor quality lifters: wrong radius or poor metallurgy.....or both. So having your factory lifters re-faced will avoid that problem; if your engine builder disagrees, find another engine builder.....
New valve springs are a good idea. If you re-use the existing springs, you might get valve float. The E-4 has about 0.020" more lift so that in itself than the stock 2bbl cam, so that will help ward off valve float if you use the old springs. Really depends on how 'tired' the springs are.
The two centre exh springs are the ones that often lose tension from the heat concentration from the centre exh ports. Any spring that is shorter in free length has lost tension...
 
Ok, first your compression ratio on an early 273 is about 9:1. You do not need "better" heads, pistons, or anything else for your 273. Second, for a 2 barrel 273 the small Racer Brown cam is perfect and a small step up from the stock 2 barrel cam. I have an extra new custom Racer Brown cam just like the one Eekvonzipper used. Notice the duration @ .050 is 200 degrees. It is a better choice for a 2 barrel engine and still quite nice for a 4 barrel intake and carb. Eric has a nice build, he started as a rebuilt 2 barrel 273 and just added the stock 4 barrel AFB and 65 intake. You can get a set of 16 new solid lifters for $50 and a true roller timing set for $80 from Hot Heads, the early Hemi racing people. I would also suggest running at least stock 360 valve springs and Felpro positive viton valve seals with the above cam. I'd also get your distributor recurved by Halifaxhops.


 
Bewy said:
As the vaaast majority have indicated, myself included, the E-4 cam would be an ideal choice.
Manufacturers produced engines with different ratings; high output, or high performance versions, 2bbl & 4bbl etc. So the E-4 would be a nice step up, with no problems.
Majority of lifter/lobe failures in recent years is from poor quality lifters: wrong radius or poor metallurgy.....or both. So having your factory lifters re-faced will avoid that problem; if your engine builder disagrees, find another engine builder.....
New valve springs are a good idea. If you re-use the existing springs, you might get valve float. The E-4 has about 0.020" more lift so that in itself than the stock 2bbl cam, so that will help ward off valve float if you use the old springs. Really depends on how 'tired' the springs are.
The two centre exh springs are the ones that often lose tension from the heat concentration from the centre exh ports. Any spring that is shorter in free length has lost tension...
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Wow! Thank you so much for the detailed explanation, I felt I was losing this battle after some of the feedback I received, in a good way of course! I am not an engine builder but I am mechanical inclined so I appreciate the group’s intentions on doing it right. Thank you so much for explaining the potential of the e4 and the existing components. I plan to discuss these exact details with the machine shop, at their discretion of course, and go from there.

As toolmanMike said, it may be in my best interest to have the critical portions of the engine assembly done by the machine shop. I was just hopeful that would be something my daughters and I could enjoy togeather. But! I am not discouraged by that, there is still PLENTY for us to build together. More to come once I hear from the shop.

Thank you everyone so much for your time and efforts, unless someone else has a 2nd opinion, I will start discussing the Isky cam with the shop and may call isky on where and how to get my lifters refaced.

Oh! I understand getting new springs and a timing set, but with the e4 what about push rods or any other related components? Thanks again!
 
66fs said:
Ok, first your compression ratio on an early 273 is about 9:1. You do not need "better" heads, pistons, or anything else for your 273. Second, for a 2 barrel 273 the small Racer Brown cam is perfect and a small step up from the stock 2 barrel cam. I have an extra new custom Racer Brown cam just like the one Eekvonzipper used. Notice the duration @ .050 is 200 degrees. It is a better choice for a 2 barrel engine and still quite nice for a 4 barrel intake and carb. Eric has a nice build, he started as a rebuilt 2 barrel 273 and just added the stock 4 barrel AFB and 65 intake. You can get a set of 16 new solid lifters for $50 and a true roller timing set for $80 from Hot Heads, the early Hemi racing people. I would also suggest running at least stock 360 valve springs and Felpro positive viton valve seals with the above cam. I'd also get your distributor recurved by Halifaxhops.

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Hi there thanks so much for taking the time to share! This is completely different from what I’m reading the groups interest in using the isky e4, but I am learning and willing to consider any option. I will do some further reading and discuss the Racer Brown cam options with the machine shop.

I was unaware of Hot Heads and the option in using 360 valve springs. (Those will direct fit replace my 273 springs?)

Thanks an again and I’ll be in touch as more progress develops.
 
Comp Cams #901 springs are a popular street replacement. Without me going back to re-read your description, was the rusty cam you took out a solid lifter cam? The lifters you are getting refaced were obviously from that cam so the pushrods can be reused. Let's talk about lifter refacing. Does the machine shop do that operation often and has the right machines to do so? The lifter faces are ground with a crown and not just machined flat. THe lifter crown and the taper on the cam lobe makes the lifter spin in the bore and prevents premature wear. A lifter with a bad crown (or no crown) won't spin and will flatten the cam lobe in a real hurry.
1723121465166.png
 
toolmanmike said:
Comp Cams #901 springs are a popular street replacement. Without me going back to re-read your description, was the rusty cam you took out a solid lifter cam? The lifters you are getting refaced were obviously from that cam so the pushrods can be reused. Let's talk about lifter refacing. Does the machine shop do that operation often and has the right machines to do so? The lifter faces are ground with a crown and not just machined flat. THe lifter crown and the taper on the cam lobe makes the lifter spin in the bore and prevents premature wear. A lifter with a bad crown (or no crown) won't spin and will flatten the cam lobe in a real hurry.
View attachment 1716286720
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Yea the rusty cam is a solid lifter cam, original. As of right now, I have not discussed nor do I know if the machine shop offers any lifter services. But I will discuss that with them in time.

Once I speak with the machine shop I’m going to discuss all of the groups suggested options with the machine shop for the comp cam springs, the 360 springs, the isky cam and the racer brown cam and timing set. I’m learning that bringing a 273 back to life can be “expensive”… as any build can be of course. But all positive motivation nonetheless. Thanks!
 
coast2coastkidd85 said:
Yea the rusty cam is a solid lifter cam, original. As of right now, I have not discussed nor do I know if the machine shop offers any lifter services. But I will discuss that with them in time.

Once I speak with the machine shop I’m going to discuss all of the groups suggested options with the machine shop for the comp cam springs, the 360 springs, the isky cam and the racer brown cam and timing set. I’m learning that bringing a 273 back to life can be “expensive”… as any build can be of course. But all positive motivation nonetheless. Thanks!
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The 273's can ge a little more spendy to do. The pistons are more money that just off the shelf 318 pieces. The cam's and lifters are more because they aren't a generic off the shelf part. The rest is really the same. Pistons from Egge and Kanter (if they are still in business) and cam and lifters from Isky, Racer Brown, or have one ground by Oregon Cam are some choices.
 
toolmanmike said:
Comp Cams #901 springs are a popular street replacement. Without me going back to re-read your description, was the rusty cam you took out a solid lifter cam? The lifters you are getting refaced were obviously from that cam so the pushrods can be reused. Let's talk about lifter refacing. Does the machine shop do that operation often and has the right machines to do so? The lifter faces are ground with a crown and not just machined flat. THe lifter crown and the taper on the cam lobe makes the lifter spin in the bore and prevents premature wear. A lifter with a bad crown (or no crown) won't spin and will flatten the cam lobe in a real hurry.
View attachment 1716286720
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IMG_8522.jpeg


IMG_8611.jpeg
 
toolmanmike said:
Refaced?
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Not that im aware of. Those are pictures of the lifters AS IS when I disassembled the engine. None of those have been looked at or seen by the machine shops as of yet. Again the engine was “rebuilt” in 1985… I have no information on it after that other than it ran for a year or two and was then parked for 20+ years…
 
toolmanmike said:
The 273's can ge a little more spendy to do. The pistons are more money that just off the shelf 318 pieces. The cam's and lifters are more because they aren't a generic off the shelf part. The rest is really the same. Pistons from Egge and Kanter (if they are still in business) and cam and lifters from Isky, Racer Brown, or have one ground by Oregon Cam are some choices.
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MOPAR = $$$$$ in general.
 
coast2coastkidd85 said:
Hi there thanks so much for taking the time to share! This is completely different from what I’m reading the groups interest in using the isky e4, but I am learning and willing to consider any option. I will do some further reading and discuss the Racer Brown cam options with the machine shop.

I was unaware of Hot Heads and the option in using 360 valve springs. (Those will direct fit replace my 273 springs?)

Thanks an again and I’ll be in touch as more progress develops.
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I have an Isky E-4 cam in my 273, but it is a 4 barrel carb and a 4 speed. Hot heads are into early Hemis from the 50's. It just so happens MOPAR small blocks use the same solid lifters and timing sets as the early Hemis. Hot Heads sell quality parts at really good prices. I learned this from my experience with early Chrysler and Desoto Hemis. All small block springs can be used in a 273. 360 springs are a bit stiffer, so they work well without going to 340 springs that have a larger OD and have a much higher spring rate. The Racer Brown custom cam is much closer to the 273 2 barrel cam and is also acceptable for a 4 barrel setup if you decide to upgrade later. That is what Eekvonzipper did with his 273 Barracuda.
 
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