270 Hemi Cam Modification & Timing Set

OK I'm looking for some info and some opinions on my 270 camshaft and timing components.


First I have read that the early hemi cams nose can be machined off drilled and tapped then use the LA double roller timing set. So I had a LA timing set given to me that was like brand new so I figured I would use that. I planned on doing the mill work on the cam myself so I pulled the plate and retainer off my 270 cam and put the LA gear in place but it is way to big. I measured the 270 cam snout and it is about 1" and the LA gear is about 1.6". So my first question: what do they do on these cams weld them up then turn them down? Or turn them down then make an adapter to make it fit the LA gear?

After finding this wasn't going to be as simple as milling off the nose and drilling a tapping I'm wondering about just using the original style timing set. I have a NOS chain and gear set that was put on the Hemi back in the 80's, ran for break in then never ran again. It is like new. After looking at it I see no reason why the double roller would be better then the OEM style. I'm not planning on running a flat front cover or a Cheby water pump so keeping the long snout isn't a big deal to me. SO what is your guy’s opinion on the stock style timing set?

For my last question who is the best cam regrinder for these old hemi cams? I found a shop in town that says they can do it but wanted to get some opinions on if I need someone that has experience with the Hemi cams or will any cam shop that makes custom cams be able to set me up? Also what should I expect to pay for a cam regrind? The shop in town said ball park would be around $200.


Thanks

Mopar or No Car

 

I'm running the stock cam&timing chain and haven't had a problem.

Lee

 

Cam grinder I'm pleased with Chris Nielson. Farmington Utah

 

Donnie Johansen will build you what ever you can dream up.

 

Here is my little unit. The cam was done at Oregon Cam Grinders 360-256-7985. Kenny has been doing it since these motors were New and is a drag racer ta boot. He knows his stuff. I've been buying cams from him over 45 years, all either custom grind or his recomendation for performance wanted. He hasn't let me down yet.
The Wizzard

 

My vote also to Oregon Cam. They made me a brand new cam for my 270

 

Most, if not all, of your questions have been answered in the HemiTech series.
Second, had you read throught the Tech or associated web sites you would know that you do not have a 270, you have a 241-260 cam.

Be sure to re-check your dial readings, the LA cam snout is 1.06"...0.060" larger than the mean diameter of the long nose cams.

If you choose to use and regrind this particular cam you have two ways to 'fix' (IMHO, properly) the 0.060" difference:
1. turn down the snout to around 0.800"-0.850", machine a press fit sleeve to cover the snout, turn the OD to the 1.06", and then re-cut the keyway (in the corect location of course).
2. bore out the center of the LA cam sprocket, design and machine a bushing that will press into the sprocket (properly secured of course) and broach it in the correct location for the cam key.

The easy option would, of course, be to just use the oem link belt assembly, or, buy a 270 cam.

Any cam company can regrind your stock shaft, the question is, will they. Not all of the 'big' guys want to do a regrind and some will have self-imposed limits on how much they will cut. There are, in addition, hundreds of 'little' guys doing regrinds. Some of us may have more options, and certainly different options, than the next guy. There is no fixed price between regrinders, retail prices will likely vary from $150 on the low end to several hundred at the top. Shop wisely.

.

 

Thanks for all the input. Yes I ment 1.060" not 1.60" big differance between the two. That would be one heavy cam at 1.6"

Gary, now I'm wonding whats going on with your comment about it not being a 270 I'll go dig back into the tech section. The block is 270 for sure I measured the bore and stroke myself and the numbers stamped on the block indicate 270. I had found comments about turning down he cam but I missed the part about 260.

Thanks again

 

OK, here is one of those 'never say never' deals about old Mopar stuff. It is entirely possible that you have a 270 with a long nose cam, generally, the 270 will be a short nose. Don't forget that cams could be swapped in 1961 as easily as in 2012 so it may not be the original cam.

I scanned through the Tech - Cam section...I had thought that this was previously covered but not much in the Camshaft section so it will be an excellent project for someone to add.

Pic one is front end of a 241-260 cam, pic 2 same cam that has been shortened.

.

 

Thanks Gary

I have 2 270 cams One is at my place and thats the one the measured about 1" The other is at my fathers and still has the plate and retainer on it. Both blocks are poly 270 blocks and from 1955 Dodge cars. I know the one my dad has is the original because the car was bought new in 55 by my great grand dad, then given to my dad in 60 for his first car. He drove it untill the doors fell off then he pulled the engine where it sat in the barn untill I took it all apart and rebuilt it. (My first engine rebuild ever)

Now the cam I have could have been swaped I don't know the history on that one. Were the Hemi and Poly cams differant? I know the Hemi will run with the Poly cam in it because we ran it like that for about 1 hour. Then it sat again for 3 or 4 years, went thru a barn fire and now I'm rebuilding it........again, LOL.

 

The 270 HEMI was a '55 & was a long snout cam. The 270 POLY in '55 would be a long snout & the '56 Poly would/should be a short snout cam, unless they used long snouts on the 56 for some reason.

 

George

Thanks. I thought the 55 Dodges and Plymouths had the long snout cam. I'm think I will just run the OEM chain and use a Mopar performance LA chain tensioner. Anyone use one of these on an early hemi? I think I could just redrill the mounting holes?

 

Been there. Too bad they didnt cover the oil galley holes.

 

Just want to add my $.02..........my understanding....and experience with the several Dodge and Chrysler hemis and polys I have...is that up through '55 they used long snout cams and '56 models got the short snout. So far, I have not experienced any variation from that with my engines.

Ray

 

I'm sure where they created mounting ears on the '56 270 block they would have also created a short snout cam also. Probably drove the bean counters nuts!

 

trying to find a '56 270 just to get the block with the mounting ears has driven me nuts too

I once drove hundreds of miles to pick one up, advertised as having been removed from a '56 Dodge......and it was.........trouble was.....it had been installed some years before and was a 259 from a '55 Plymouth, water pump yoke mount and all..........

The girl (yes, a girl/woman) selling it didn't know the difference and assumed since it came from a '56 Dodge it was a 270. Her bad. The fact I didn't get photos of it, or the block stamped codes, before making the trip was MY bad

Live and learn.

Ray

 

I know this is a bit off topic, but I am wondering about lifters for the Red Ram Hemi (or D500).

Has anyone tried adapting the Crane roller lifters to their engine? The Crane parts are for the LA series of Mopar small block V8s. Doc Frohmader used the Crane hydraulic roller lifters in a little Dodge Hemi build he did a while back. He has an article at:

http://www.webrodder.com/article.php?AID=171&SID=60&CID=15#

The roller lifters would allow a bit more aggressive cam profile that would still be user friendly on the street. The lifter (pairs) had to be modified for the Dodge lifter bore spacing, but according to the article the Crane rollers would drop right into a DeSoto Hemi.

Just wondering if anyone has some experience with this?

 

Tom

Thats what I had in mind. Is not covering the oil galley holes a problem?

Never mind I see you welded ears on to cover the galley holes. I think I can handle that. Basically I just plan on placing my 270 plate up to the tentioner plate and drilling new holes and filling in the blanks.

 

I know that most folks will call me crazy, or even something more descriptive, but in my years of screwing around with EarlyHemi engines I have found waaay too many short nose, low deck Dodge cams to attribute them solely to a 1956 Poly engine application. Yes, I know what is said in the various books and manuals but the sheer number of cams that have crossed my path seems contradictory. I simply can't be that lucky. However, for the sake of harmony, I'll follow the 'group-think' on this forum.

.

 

The stock rollers from the roller LA will fit the DeSoto, shortening for Dodge & lenthen for Chr.

 

Charlie, have you read through Tony's DeSoto project thread? Might be helpful.

 

Hey 73RR......I'll take your word for it.....experience frequently trumps theory

Ray

 

Gary

I don't think any Mopar guys on here would tell you that Mother Mopar ALWAYS did anything one way or another. Some times I think she did these things just to keep us on our toes. So do all the long snout cams have the 1.0" mount and all the short snouts have the 1.06" Or do some of the long snouts have the 1.06" also. Because I got the impression that all you had to do to the long snout was to machine it down and drill and tap it.

What is the advantage to running a double roller over the stock chain? These Hemi sprocets and chain seam pretty heavy duty to me.

 

Hmmmm...In '56 the 270 & 315 Polys are listed as available, the 270 in the Coronet & the 315 in the other cars. Perhaps they ordered a bunch of cams ahead of time & orders just didn't match up resulting in an overage of cams that couldn't be used, where production was high blocks for everything else. By "cross paths" are you talking nos cams laying around? or used?

 

I just read that one this morning and man that is some good info.

I do want to ask in regard to the roller lifters is it a performance thing or is it a durability thing. Realistically if your were building a mild street Hemi with cast pistons (so limiting valve lift) would going to a roller make that much difference in performance? Part of me wants to see if I can make Magnum rollers work in a Dodge Hemi but then I think it looks like allot of work. LOL

I'm really leaning toward just sending my cam out to have it reground and using a new set of LA hydraulic lifters. Using my NOS stock Hemi timing set and calling it a day.

 

Think it's more of the double roller being better than the OEM chain on modern V8s instead of vs the wide chain on the Hemis. Of course you also get an aftermarket set up that can be installed advanced w/o much effort.

 

I can see that some of the LA's I took apart had a plastic top sproket. And I could almost lift the chain off without pulling the cam bolt.

 

The pastic coated teeth on those sprockets may have worn a bit, but most of that slop is due to stretching of the Morse chain. Many heavy duty applications used the double row roller setup (Chevy truck V8's for one example, in addition to Mopar) .....I believe they are seen to be stronger by virtue of the link design/dimensions and do not stretch as soon, or as much, as the Morse style.

A really good example of stretch problems with Morse style chains was the odd-fire Buick V6.....fired 90-150-90-150 etc. causing (I think) an uneven loading on the cam as the lobes opened valves then loafed, then loaded again and so on. I had several of those engines some years ago and they ate timing chains at two or three times the rate of 'regular' engines.

Ray

 

Will LA hydraulic lifters work Okay in the 241 270 low deck Dodge?

 

There is at least in theory a reduction in oil temp because the friction of the nonrollers are eliminated. Think I read that 20% of oil temp is from the flat tappet lifters in that type of set up. It also eliminates the need for ZDDP in the oil. The Mustang engine went up some thing like 5-20 HP in '85 with no other obvious change except rollers vs the '84 engine. Rollers are supposed to allow the engine to wind up a bit faster but might not be noticable.