273 Engine intake upgrade turned sour

[Crewdog89]

Hey guys! Well purchased and Edelbrock Performer to go along with my Edelbrock AVS2 650cfm electric choke carb for my 273 just to spice things up a bit. Had the time this weekend to go ahead and swap those out and everything was going well until I noticed once I cleaned out the block to prep for installation I saw the cam….and the metal is basically chipping away. Looked closer at the cam and the west marks are insane and wow did it not look nice at all, at least in my eyes ha. I’ll make sure to get some pictures after I start the work. So basically my happy go lucky day turned into a not so lucky day and now I’m looking at replacing the cam. Now I referenced TMM’s 273 build and although I would love the Isky E4 the set matched with lifters and pushrods is just way over my budget unfortunately. So I was looking at the COMP Cam 270S kit with Lifters which is about $410. Mind you I’m not fully limited on budget but this engine will be a just pleasure cruiser until I start to build and finish the 360 I want in it. So I would like to keep the budget relatively low and then once the 360 is done and the 273 is out I can build her up as a secondary project. Since I am new to building engines I just don’t know where to start. I know I need camshaft, lifters, pushrods, rockers, and a timing set (I’m assuming because if it’s like anything else on this engine it’s going out). I just don’t know what pushrods go well or what rockers to choose. Should I stick with single or move to double for the timing set? It also seems like the pushrods installed are hydraulic even though the rockers installed are mechanical? I could be wrong but I’ll attach a picture maybe you guys can tell. I just wanted to see if I could get suggestions from everyone on a good setup with the cam I listed above. I’ll post questions/options below that I’m thinking and remember I am very new as far as experience. I could tell you how a turbine engine works since I’m around them everyday but automotive engines are a new realm for me so I’m still learning haha Thanks guys!

1967 273 Commando Engine 10.5:1 CR

COMP Cam 270S: .468/.468 270/270 @.050 224/224

Lifters: solid lifters come with camshaft kit

Pushrods: what length do I look for?

Rockers: should I keep stock or get new ones?

Timing Set: single or double?

 

[toolmanmike]

If the lifters are like what you took out, the pushrods should work.

 

[Killer6]

Cam pics 1st. Were the valves out of adjustment any significant amount?

 

[glockr]

Hey guys! Well purchased and Edelbrock Performer to go along with my Edelbrock AVS2 650cfm electric choke carb for my 273 just to spice things up a bit. Had the time this weekend to go ahead and swap those out and everything was going well until I noticed once I cleaned out the block to prep for installation I saw the cam….and the metal is basically chipping away. Looked closer at the cam and the west marks are insane and wow did it not look nice at all, at least in my eyes ha. I’ll make sure to get some pictures after I start the work. So basically my happy go lucky day turned into a not so lucky day and now I’m looking at replacing the cam. Now I referenced TMM’s 273 build and although I would love the Isky E4 the set matched with lifters and pushrods is just way over my budget unfortunately. So I was looking at the COMP Cam 270S kit with Lifters which is about $410. Mind you I’m not fully limited on budget but this engine will be a just pleasure cruiser until I start to build and finish the 360 I want in it. So I would like to keep the budget relatively low and then once the 360 is done and the 273 is out I can build her up as a secondary project. Since I am new to building engines I just don’t know where to start. I know I need camshaft, lifters, pushrods, rockers, and a timing set (I’m assuming because if it’s like anything else on this engine it’s going out). I just don’t know what pushrods go well or what rockers to choose. Should I stick with single or move to double for the timing set? It also seems like the pushrods installed are hydraulic even though the rockers installed are mechanical? I could be wrong but I’ll attach a picture maybe you guys can tell. I just wanted to see if I could get suggestions from everyone on a good setup with the cam I listed above. I’ll post questions/options below that I’m thinking and remember I am very new as far as experience. I could tell you how a turbine engine works since I’m around them everyday but automotive engines are a new realm for me so I’m still learning haha Thanks guys!

1967 273 Commando Engine 10.5:1 CR

COMP Cam 270S: .468/.468 270/270 @.050 224/224

Lifters: solid lifters come with camshaft kit

Pushrods: what length do I look for?

Rockers: should I keep stock or get new ones?

Timing Set: single or double?

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I would keep the stock rockers. Imo adjustable rockers are nice to have even if you switch to a hydraulic cam. If yours are worn (or you're worried about them) I'd call B3 Racing and see about getting them rebuilt or go with the ductile iron rockers from Mancini racing. For timing set I like the billet double roller from Mancini Racing.

 

[Crewdog89]

Cam pics 1st. Were the valves out of adjustment any significant amount?

I’ll try to find some time to get in there and get you some pictures in the mean time I found some pictures online to show what I’m talking about. Most of it relates to the complete wear in the photo outside of the chipping which is relatively similar to the picture of the chipped lobe.

 

[Max1196]

@4spdragtop what you gota say about a Comp 270 used in a 273?

 

[Professor Fate]

Just a gut reaction on my part.
From what I think I understand, you just want to get the 273 going again for a few seasons until you can afford to build your 360.
Do you already have the 360, and just waiting for the funds to build it? If so, this would be my plan of attack:
Yank the cam, lifters, pushrods, and rockers/shafts out of the 360 (keep everything in order- label all lifters as to exactly where their location was) and transfer it all to the 273. The 360 cam, if a 2bbl., is fairly comparable to the 273 4 bbl. cam (410/412 vs. 415/425 lift, 252/256 vs. 248 duration), if a 4 bbl. 360 cam it specs at 430/444 and 268/276- a nice little increase. It all drops right into the 273. Since you will be trashcanning the cam and lifters anyways when you rebuild the 360, why not make use of it now? Save the money for your 360 parts. Repurpose the 273 adjustable rockers (and pushrods?) for your 360 build. Add a decent double roller chainset and button 'er up, easy peasy; and money left over for the future build.
JMO.

 

[Crewdog89]

Just a gut reaction on my part.
From what I think I understand, you just want to get the 273 going again for a few seasons until you can afford to build your 360.
Do you already have the 360, and just waiting for the funds to build it? If so, this would be my plan of attack:
Yank the cam, lifters, pushrods, and rockers/shafts out of the 360 (keep everything in order- label all lifters as to exactly where their location was) and transfer it all to the 273. The 360 cam, if a 2bbl., is fairly comparable to the 273 4 bbl. cam (410/412 vs. 415/425 lift, 252/256 vs. 248 duration), if a 4 bbl. 360 cam it specs at 430/444 and 268/276- a nice little increase. It all drops right into the 273. Since you will be trashcanning the cam and lifters anyways when you rebuild the 360, why not make use of it now? Save the money for your 360 parts. Repurpose the 273 adjustable rockers (and pushrods?) for your 360 build. Add a decent double roller chainset and button 'er up, easy peasy; and money left over for the future build.
JMO.

That would be an amazing idea but unfortunately I do not have a 360 currently. It’s a future build that is simply on paper at this point until I have the time and funds to push forward with it. Right now my sole focus is to make the 273 a nice cruiser and a current project until I can start the 360 build. Thanks for the idea though that would have been a great option!

 

[4spdragtop]

Thanks Graham, I did the exact same setup for our 67 273. Does your engine currently have Commando pistons?
Ours had the 2bl pistons and that cam is way too big for the 2bl. Sounds awesome but no bottom end torque at all. Part of our "demise" was stock converter and 323 gears. I'm no engine builder by any means but in my opinion the heads aremt suited for it either. Comps specs even say "smallest cam for 340/360" or something like that.
In my opinion the determining factors are your current pistons.

@4spdragtop what you gota say about a Comp 270 used in a 273?

 

[Crewdog89]

Thanks Graham, I did the exact same setup for our 67 273. Does your engine currently have Commando pistons?
Ours had the 2bl pistons and that cam is way too big for the 2bl. Sounds awesome but no bottom end torque at all. Part of our "demise" was stock converter and 323 gears. I'm no engine builder by any means but in my opinion the heads aremt suited for it either. Comps specs even say "smallest cam for 340/360" or something like that.
In my opinion the determining factors are your current pistons.

I have verified that I do have the commando pistons

 

[4spdragtop]

Great news! By the sounds of it all you need is cam, lifters and a dbl roller timing chain set.
Heres a video.
PS I will be adding a dual quad here shortly for ***** n giggles. Eventually I will be installing a set of commando pistons

I have verified that I do have the commando pistons

 

[Crewdog89]

Great news! By the sounds of it all you need is cam, lifters and a dbl roller timing chain set.
Heres a video.
PS I will be adding a dual quad here shortly for ***** n giggles. Eventually I will be installing a set of commando pistons

She sounds awesome! Especially since you still had some tuning left to do! Thanks for the help! Should I keep the same pushrods as long as they check out when I inspect them or is it best to just replace?

 

[4spdragtop]

Thanks, thats an old video, I have an idle one somewhere. They should be cup/ball pushrods. Give them a good check visually and also roll them on something for perfect straightness. Make sure the adjusters in the rockers are snug, they have an interference fit.

She sounds awesome! Especially since you still had some tuning left to do! Thanks for the help! Should I keep the same pushrods as long as they check out when I inspect them or is it best to just replace?

 

[Crewdog89]

Thanks, thats an old video, I have an idle one somewhere. They should be cup/ball pushrods. Give them a good check visually and also roll them on something for perfect straightness. Make sure the adjusters in the rockers are snug, they have an interference fit.

An interference fit?

 

[4spdragtop]

interference fit means it's more snug/tight feeling.
Heres an idle video

An interference fit?

 

[66fs]

Get the E-4 cam and lifters. Racer Brown can also grind a nice cam for a 273. Might want to get a set of 340 valve springs or equivalent to get the most out of the E-4 cam. Everything else should be fine. Use a good double roller timing chain. I might have a Racer Brown solid cam and lifters close to the Commando cam in my stash.

 

[toolmanmike]

interference fit means it's more snug/tight feeling.
Heres an idle video

I'm surprised that 270 doesn't have a little lope to it.

 

[a-bodyguy]

To much duration for a 273 small valve heads and 273 manifolds for pleasure cruiser imo
low end torque is your friend

 

[4spdragtop]

Theres a lope Mike, unfortunately the "sound/looks " is the best part of it lol. I'll take a better video with DQ. Intake and carb are off right now. I was chasing a timing issue for a while too.

I'm surprised that 270 doesn't have a little lope to it.

 

[4spdragtop]

Dbl post

 

[toolmanmike]

Theres a lope Mike, unfortunately the "sound/looks " is the best part of it lol. I'll take a better video with DQ. Intake and carb are off right now. I was chasing a timing issue for a while too.

SOunds like you got that resolved. Your other "driving " video sounded strong!

 

[toolmanmike]

Schneider Racing Cams has quite a few LA solids. They get big pretty quick but the 2 smaller ones would be good for a street 273. A step up from the Isky E4. Schneider Racing Cams

 

[BillGrissom]

It appears the photo at the bottom of post 5 is the camshaft lobe of concern (don't know what "west marks" refers to). No expert, but it doesn't appear like normal wear and perhaps is a void in the original casting. You would think Quality control at the factory would have caught it after machining, but might be the OE camshaft from 1960's before automated video inspection, and Billy-Bob on the inspection line might have been focused on quitting time. If the lifter doesn't touch the void, it might work fine (has for decades?), but appears you want to up-cam regardless.

Your idle sounds fine to me, indeed more stumbly than I prefer, but many here desire a poor idle, like a "race engine", which pours out noxious fumes from excessive intake-exhaust overlap. Owners can legally do that now, but risk public outrage which may limit our classic car hobby, as was done for "rolling coal" in diesels and loud mufflers. I installed a hydraulic RV/Torque camshaft in my 1965 273 with Rhoads leak-down lifters (poor man's VVT), for smoother idle and better mileage. Ball & Cup pushrods for a 1970's 340 T/A fit and the adjustable rockers let me ideally adjust preload on the lifters.

 

[mygasser]

if it's just to get by for now just get cheap summit brand replacement cam/lifters and basic roller t/chain set. it'll be just fine with the least amount spent until you start along the 360 road. you don't need the cost of a billet t/set for sure.
neil.

 

[ChargerKG]

A Manifold thread turns to Cams. I love it. Still have not installed my Isky but I know it will be monster. Was told this should not be annoying with 904 and 3:23s. Will benefit with more stall. The car is just so pleasant to drive as Chrysler intended I am waiting to swap when I can massage the heads. Stock 273-4 except Edelbrock Streetmaster 318, Electronic Ignition (no performance gain over dual point), New Edelbrock 500 cfm.