anyone out there who has used a single bolt cam from comp cams I need some info.

[adk-roadrunner]

So I already have a separate thread about cam bolt size but I feel like I really needed to narrow it down. I am currently building a 440 for my 73 roadrunner which I purchased a cam kit for model K21-306-4 which is a 270h-10 cam . I was getting ready to install the cam and found my stock 7/16-14 bolt would not work as the cam is tapped to a 3/8-16. I called comp and was originally told my cam must have been damaged during production and therefore tapped to the larger size which supposedly is the case with 20% of all Chrysler cams as the other 80% are tapped to 3/8-16. I then went on a search to find the proper size bolt and washer and everywhere I looked I could only find 7/16-14 in the single bolt setup. I actually called 440 source and talked to a very nice guy there who said in all his years he has never seen a single bolt cam for a 440 in any other size than 7/16-14. I called comp again and was told to just go buy a grade 8 bolt at the hardware store and be done with it which the guy from 440 source was kinda unsure about he said at least make sure they are machine grade. I posted my other thread and the few people who gave info seem to say 7/16 and some even went as far as to say when they used comp they used the stock size bolt. So I gave 1 more call to comp and I got more heated than I should have because these guys are just tech line guys but I feel like I'm going bolt crazy lol. They said every one I talked to doesn't know what they are talking about as all of their Chrysler guys are saying 3/8-16 is the size. Actually once I got a guy who was supposed to be a supervisor who said they came both ways but mostly 3/8. I asked him what other people are using and are all the single bolt mopar cams they sell tapped to 3/8-16 he said not sure what they are using but yes all tapped to the same size. I went on to ask if he could just help me find this Chrysler bolt and washer in the 3/8 size and he couldn't find anything. So here is the deal I've had the cam kit for over a year and already installed the valve springs as I had my heads redone so returning or exchanging really isn't an option. I'm probably gonna end up just finding a really good machine quality bolt and washer but I am dying to know what other people are using and if anyone has or ever seen a stock 3/8-16 bolt? Thanks guys

 

[coloradodave]

I'll re-iterate what everybody is saying; Every big block single bolt cam that I have ever dealt with had a 7/16" X14 bolt with the special, thick convex washer that loads the bolt. Here are the torque specs from my 63 service manual for a big block 361. Same for the 383 and 426 wedge:

The second page is from mymopar.com: Check out the B and RB specs below the Hemi stuff.







Engine Bolt Torque Specifications

Engine Bolt Torque Specifications - 426 Hemi, RB, B, LA Engines
These specs are for stock-type bolts with light engine oil applied to the threads and the underside of the bolt head. Moly and other lubes offer reduced friction and increased bolt tension, which will affect the torque figure. If you use aftermarket performance bolts like ARP's, you should follow the recommended torque specifications.
Please note that some specifications are in inch-pounds rather than foot-pounds. Read the charts carefully to prevent broken bolts due to excessive torquing.




426 Hemi Engine Torque Specifications
* Torque values shown are in ft/lbs unless otherwise noted
* Follow factory torque sequence


Fastener
Torque Thread Size
Alternator Adjusting Strap Bolt 15 5/16-18
Alternator Bracket to Block Bolt 30 3/8-16
Alternator Mounting Bolt 30 3/8-16
Camshaft Gear Retaining Bolt 40 3/8-16
Carburetor to Manifold Nut 7 5/16-24
Clutch Housing Bolt 50 7/16-14
Connecting Rod Nut 75 7/16-20
Crankshaft Rear Seal Retainer 30 3/8-16
Crankshaft Bolt (Vibration Damper) 135 3/4-16
Cylinder Head Bolt 70-75 7/16-14
Cylinder Head Stud Nut 70-75 7/16-20
Distributor Clamp Bolt 200 in/lbs 5/16-18
Exhaust Manifold Bolt 35 3/8-16
Fan Attaching Bolt 15 5/16-18
Flywheel Cover Bolt 7 1/4-20
Flywheel Housing to Block Bolt 50 7/16-14
Flywheel to Crankshaft Bolt 70 7/16-20
Fuel Pump to Block 30 3/8-16
Main Bearing Cap Bolt 100 1/2-13
Main Bearing Cap Tie Bolt 45 3/8-16
Oil Pan Drain Plug 20 1/2-20
Oil Pan Bolt 15 5/16-20
Oil Pump Cover Bolt 10 5/16-18
Oil Pump to Block Bolt 30 3/8-16
Rocker Shaft Bolt 30 3/8-16
Spark Plug 30 14mm
Starter Mounting Bolt 50 7/16-14
Timing Cover Bolt - Upper 15-18 5/16-18
Timing Cover Bolt - Lower 15-18 3/8-16
Torque Converter Housing Bolt 30 3/8-16
Torque Converter to Flexplate Bolt 65 7/16-20
Valve Cover Stud & Nut 40in/lbs 1/4-28
Water Pump to Housing Bolt 30 3/8-16
Water Pump Housing to Block Bolt 30 3/8-16






RB/B Engine Torque Specifications Big Block Chrysler 383, 400, 440
* Torque values shown are in ft/lbs unless otherwise noted
* Follow factory torque sequence


Fastener
Torque Thread Size
A/C Compressor to Engine Bolt 30 3/8-16
Alternator Adjusting Strap Bolt 200 in/lbs 5/16-18
Alternator Adjusting Strap to Block Bolt 30 3/8-16
Alternator Mounting Bolt 30 3/8-16
Camshaft Lockbolt 35 7/16-14
Carburetor to Manifold Nut 7 5/16-24
Clutch Housing Bolt 50 7/16-14
Connecting Rod Nut - Plain 45 3/8-24
Crankshaft Rear Seal Retainer 30 3/8-16
Crankshaft Bolt (Vibration Damper) 135 3/4-16
Cylinder Head Bolt 70 7/16-14
Distributor Clamp Bolt 15 5/16-18

 

[lewtot184]

I'll re-iterate what everybody is saying; Every big block single bolt cam that I have ever dealt with had a 7/16" X14 bolt with the special, thick convex washer that loads the bolt. Here are the torque specs from my 63 service manual for a big block 361. Same for the 383 and 426 wedge:

The second page is from mymopar.com: Check out the B and RB specs below the Hemi stuff.







Engine Bolt Torque Specifications

Engine Bolt Torque Specifications - 426 Hemi, RB, B, LA Engines
These specs are for stock-type bolts with light engine oil applied to the threads and the underside of the bolt head. Moly and other lubes offer reduced friction and increased bolt tension, which will affect the torque figure. If you use aftermarket performance bolts like ARP's, you should follow the recommended torque specifications.
Please note that some specifications are in inch-pounds rather than foot-pounds. Read the charts carefully to prevent broken bolts due to excessive torquing.




426 Hemi Engine Torque Specifications
* Torque values shown are in ft/lbs unless otherwise noted
* Follow factory torque sequence


Fastener
Torque Thread Size
Alternator Adjusting Strap Bolt 15 5/16-18
Alternator Bracket to Block Bolt 30 3/8-16
Alternator Mounting Bolt 30 3/8-16
Camshaft Gear Retaining Bolt 40 3/8-16
Carburetor to Manifold Nut 7 5/16-24
Clutch Housing Bolt 50 7/16-14
Connecting Rod Nut 75 7/16-20
Crankshaft Rear Seal Retainer 30 3/8-16
Crankshaft Bolt (Vibration Damper) 135 3/4-16
Cylinder Head Bolt 70-75 7/16-14
Cylinder Head Stud Nut 70-75 7/16-20
Distributor Clamp Bolt 200 in/lbs 5/16-18
Exhaust Manifold Bolt 35 3/8-16
Fan Attaching Bolt 15 5/16-18
Flywheel Cover Bolt 7 1/4-20
Flywheel Housing to Block Bolt 50 7/16-14
Flywheel to Crankshaft Bolt 70 7/16-20
Fuel Pump to Block 30 3/8-16
Main Bearing Cap Bolt 100 1/2-13
Main Bearing Cap Tie Bolt 45 3/8-16
Oil Pan Drain Plug 20 1/2-20
Oil Pan Bolt 15 5/16-20
Oil Pump Cover Bolt 10 5/16-18
Oil Pump to Block Bolt 30 3/8-16
Rocker Shaft Bolt 30 3/8-16
Spark Plug 30 14mm
Starter Mounting Bolt 50 7/16-14
Timing Cover Bolt - Upper 15-18 5/16-18
Timing Cover Bolt - Lower 15-18 3/8-16
Torque Converter Housing Bolt 30 3/8-16
Torque Converter to Flexplate Bolt 65 7/16-20
Valve Cover Stud & Nut 40in/lbs 1/4-28
Water Pump to Housing Bolt 30 3/8-16
Water Pump Housing to Block Bolt 30 3/8-16






RB/B Engine Torque Specifications Big Block Chrysler 383, 400, 440
* Torque values shown are in ft/lbs unless otherwise noted
* Follow factory torque sequence


Fastener
Torque Thread Size
A/C Compressor to Engine Bolt 30 3/8-16
Alternator Adjusting Strap Bolt 200 in/lbs 5/16-18
Alternator Adjusting Strap to Block Bolt 30 3/8-16
Alternator Mounting Bolt 30 3/8-16
Camshaft Lockbolt 35 7/16-14
Carburetor to Manifold Nut 7 5/16-24
Clutch Housing Bolt 50 7/16-14
Connecting Rod Nut - Plain 45 3/8-24
Crankshaft Rear Seal Retainer 30 3/8-16
Crankshaft Bolt (Vibration Damper) 135 3/4-16
Cylinder Head Bolt 70 7/16-14
Distributor Clamp Bolt 15 5/16-18

this is correct. i have 2 engle cams, 1 comp cams, 1 mopar performance and 1 clevite cam sitting on the bench. all are 7/16-14. the convex washer won't work properly with a 3/8" bolt. comp cams strikes again! look at any service manual and it will state 7/16-14.

 

[adk-roadrunner]

Lewtot184 can you give me the serial number off of your comp cam with the 7/16-14 and some info on what cam it is. I literally starting yelling when I was on the phone with them earlier because I was so frustrated. I feel like they just aren't listening to me but I don't know who at comp I can talk to that will listen to me. They just keep saying that they have several very good Chrysler guys on staff and they say 3/8-16. I straight up said to the guy your mopar guy doesn't know what he's talking about and he just said I'll forget to let him know that. I asked well are you guys gonna take care of me if what your telling me to do fails and my new engine is damaged and the manager just said if the bolt fails its a bolt problem not ours. I know the 426 hemi had the 3/8 in its single bolt cam and I have found the bolt but not the 3/8 convex washer that goes with it.

 

[khryslerkid]

Maybe you have a hemi cam!

Heck, you even had me checking the Summit 6401 I just bought recently. 7/16x14 and a little sloppy for my liking.

Fastenal has a good selection of speciality bolts and hardware. My work place deals with them for all kinds of unique hardware.
Also Lowe's, Tractor Supply or even online hardware companys should have what you want.
Good luck...

 

[adk-roadrunner]

I'm going to call Mancini racing tomorrow they sell their own version of a single bolt and washer in 7/16 they put together. It says the bolt includes a sturdy washer and I will ask them if its convex like the stock one if not I'll measure the thickness of the stock washer and see what fastenal can offer.

 

[cryplydog]

Adk,why don't you just ask/demand for another cam? good luck

 

[adk-roadrunner]

I'd like to demand a new cam or something to that effect though I'd like to gather some info on other comp cams that people have. I'd like info such as the grind and possibly the serial number which is supposed to be stamped on cam and what size bolt they take. This way when I call again I can give them the serial numbers and grinds of other single bolt cams and ask what bolt sizes and when confirm what I already know that they are 7/16-14 I can ask why mine isn't. At this point if they were willing to possibly just swap the cam with one that uses the right size bolt I'd be pretty happy. If they could offer some better advice than figure it out that would be nice lol it seems to me that when the cam is designed they would really think about the bolt size. Am I the only mopar with this cam lol

 

[khryslerkid]

If you're really stuck with this cam, a good machinist could drill and Tap a 7/16 x 14 for you...

 

[dieseldazzle]

Dude if its 3/8 just drill and tap it for 7/16 rather than raising your blood pressure.

 

[IQ52]

I really like Comp Cams but their tech line guys haven't a clue. I deal only with one of the engineers in the back rooms. The Hemi cams come with three 3/8-16 bolts, all three bolt cams should be 3/8-16 and the single bolt cams come with one 7/16-14. A three-bolt roller cam I ordered came with three 3/8-24 fine thread bolts. I called and asked what was going on. "Duh, we don't know somebody goofed."

Next two three-bolt cams, 3/8-16 threads.

 

[adk-roadrunner]

I have a brand new snap on tap and die set but haven't used it much or ever had the opportunity to tap a new size bolt hole what size drill bit would I use to open it up for the 7/16-14 from 3/8. I actually thought about this but sometimes I have a hard time giving in especially when I know the information I have is right.

- - - Updated - - -

Hey IQ52 do you actually know someone or have a contact there if so could you possibly ask them about my issue? I've called comp cams 4 times now and have got no where. I wish I had a way to talk to someone who isn't a techline guy.

 

[lewtot184]

Lewtot184 can you give me the serial number off of your comp cam with the 7/16-14 and some info on what cam it is. I literally starting yelling when I was on the phone with them earlier because I was so frustrated. I feel like they just aren't listening to me but I don't know who at comp I can talk to that will listen to me. They just keep saying that they have several very good Chrysler guys on staff and they say 3/8-16. I straight up said to the guy your mopar guy doesn't know what he's talking about and he just said I'll forget to let him know that. I asked well are you guys gonna take care of me if what your telling me to do fails and my new engine is damaged and the manager just said if the bolt fails its a bolt problem not ours. I know the 426 hemi had the 3/8 in its single bolt cam and I have found the bolt but not the 3/8 convex washer that goes with it.

the cam i have is a 282 magnum solid, 21-247-4. new and unaltered.

- - - Updated - - -

these cam grinders buy cores from a 3rd party and finish grind the lobes to their specs. could be the core suppliers screw up, but i still hate comp cams. i've never had any aftermarket part cost me more money and misery than comp cams; edelbrock is second. i firmly believe if it wasn't for all the grand and glorious free ink they get in magazines they'd be long gone. they'll sell more product from a favorable write up or test than from advertising. and, you never here of a publication make a negative remark about a big advertiser; could be a collusion and we're the suckers!

 

[dieseldazzle]

The guys at oregon cams have saved me on many cams that I picked up for free because someone boogered up the cam bolt. It costs shipping but they handle it cheap.

oregon cams just google them bunch of old grumpy dudes but they do you right

 

[coloradodave]

adk-roadrunner: Copy the info I posted above from the FACTORY service manual and email it to Comp Cams requesting an explanation and a reply. Or, determine that it actually IS a big block cam and get yourself to any automotive machine shop and get it PROFESSIONALLY drilled and tapped.
I think we've beat this dead horse to death...Oh, BTW, you're welcome!

 

[adk-roadrunner]

Actually I already have sent a copy of a factory service manual stating the bolt size to them on their tech help page and got no reply. It is definitely a big block cam. What I am looking for is experience that others that have used comps cams with single bolts IE bolt size. At this point I think only one person has actually posted their cam info with bolt size. If I didn't already say THANKYOU I definitely appreciate everyone's help.

 

[dieseldazzle]

Id be worried about other aspects of the cam bro. Once you tap it make sure you degree that prick

 

[Hemirunner]

I really like Comp Cams but their tech line guys haven't a clue. I deal only with one of the engineers in the back rooms. The Hemi cams come with three 3/8-16 bolts, all three bolt cams should be 3/8-16 and the single bolt cams come with one 7/16-14. A three-bolt roller cam I ordered came with three 3/8-24 fine thread bolts. I called and asked what was going on. "Duh, we don't know somebody goofed."

Next two three-bolt cams, 3/8-16 threads.

We had that happen on a couple of them with 3/8-24 threads and they traced it back to an obscure cam core provider that had tapped a batch that way.

adk, ask for Chris Pageant at Comp.

 

[adk-roadrunner]

Yup will need to be degree'd for sure lol. I honestly don't think I would ever give them any of my money again. Thanks hemirunner I will give a call tomorrow and see if I can talk with him god I hope so lol.

 

[adk-roadrunner]

hey Hemirunner thank you very much for your help I just got of the phone with your buddy chris. He is having me send my cam directly to him at comp and he is going to get it drilled and tapped to 7/16-14 for me. I am very excited to finally get somone who would help me he did state that all of their single bolt cam cores are 3/8 but he could tap mine for me. I gotta go get this thing boxed up and shipped out asap.