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| What Hydraulic Cam - long read! https://www.slantsix.org/forum/viewtopic.php?t=60531 |
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| Author: | 65 dartman [ Fri Dec 02, 2016 6:41 pm ] |
| Post subject: | What Hydraulic Cam - long read! |
Long read here - The background: I had a older gentleman stop by my house a week or so ago asking for some guidance on selecting a cam as he had heard from someone else I was a Mopar guy and knew a bit about slants. Anyway, he had just picked up a slant motor at an auction from an out of business machine shop and was wanting to do something different in an old street rod rather than go the small or big block route. From what I gather, someone had machine work done at some time and never picked it up. He said it was the block, head, hydraulic rocker arms, new bearings, etc. I asked did he mean adjustable rocker arms: he said he certainly knew the difference and these were non-adjustable. Anyway, he was asking my help in choosing a cam for a decent street motor. I asked what had been done and according to the paperwork he showed me, the block was cut 80 thou, overbored 30 thou and the head milled 10 thou. And the paperwork said it was an 83 slant six FWIW. I told him I'm really not too knowledgeable on selecting a cam but to join the forum and get some answers straight from the engine gurus here. He said he doesn't do the internet. So I'm trying to help him out I asked for some more info as I'm sure it will be needed. He came back this afternoon with more info - the Nr 1 piston is in the hole about .090, it has 30 thou oversize piston and the head chamber volume for Nr1 and 6 is 53 cc. He said he will be building custom headers to fit the chassis and a 4 barrel. I asked if he was going to use an automatic - no sir - it will be a 4 speed out of an old Volare or Aspen another friend has. I have no clue on what to tell him. So - based on the cam selection from Oregon for a hydraulic cam, what might be a decent cam for his motor? |
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| Author: | DusterIdiot [ Fri Dec 02, 2016 7:47 pm ] |
| Post subject: | Not that long.... |
That really isn't a long read.... There are more variables to fill in... here... What is his intent? (just street rod, no drag racing, lopey idle, ???) Is he going to do more to the engine? ...he has stock valves... Currently if he just uses what his measurements are... 53 cc Comb Chamber Deck Height .090 3.43 bore Just based on that info and a standard felpro gasket he is at 9.58:1 static compression... this isn't bad... but it's between say the 10:1 hihger compression style of build (bigger cam to bleed down the cylinder pressure.... and a little high for the AG Ted build wanting lower compression and more torque from an RV cam.... If he leaves things alone except for getting O/S valve installed, and V-8 springs for higher lift, and the guides milled down to prevent issues with having higher than 'stock' lift... Given that he will be using a wide ratio A-833OD out of that F-body, he can have a slightly more aggressive cam than the automatic guys can use, but he will want to put a set of 3.55's behind it and he may not like the wide rpm drop between upshifts... Back to the cam selection... If he gets the breathing stuff taken care of above... and still retains the same numbers... we are batting 9.58:1 static compression.... using a Dynamic Compression Ratio calculator to 'shop' for a cam that would put this combination in the 8:1 DCR range for use on pump gas.... Looking over OCG's list, most of their hydraulic cams are based on Chevy grinds... but that being said... some have a longer exhaust durations for use with headers, and could help if he intends to use the stock valve sizes and a homemade header setup... We could get an easy 8.14:1 DCR if he were to use something like grind 1333 but order it with a 108 lobe separation (212/218 dur @050... lift = .447/.455) degreed in at 104 centerline... which the durations aren't really wild so it will have good street manners.... More 'lump'... grind # 31 225/225 @.050 Order LSA at 108 centerline at 102... lift at .498 would give 7.96:1 DCR.... this cam would perform a bit better with O/S valves and 10:1 SCR at a 104 centerline.... There are more 'combinations' to try, and hopefully there is someone who has done a hi-po juice engine... I'm skipping to the top of the heap as I've got an 11:1 block set to take Dennis's old juice cam that's about 292/292/108 with a .558 lift.... LOL... |
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| Author: | 65 dartman [ Sat Dec 03, 2016 7:39 am ] |
| Post subject: | |
Thanks for the response! I thought I had all the bases covered with the questions I asked him about. I will see if I can get a hold of him and see what I can find out. |
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| Author: | 65 dartman [ Fri Dec 09, 2016 4:31 pm ] |
| Post subject: | |
UPDATE: The gentleman I'm trying to help came by the other day, so I asked him to get me some more info (as per Dusteridiot). He again brought the paperwork he received with the engine by today and if I had looked closely, I probably would have had most of the answers already. The original guy who dropped the motor off for machine work provided a set of 1.70/1.40 stainless steel, a set of single spring 340 V8 valve springs and a set of valve guides to the machine shop. Also my new friend said someone has done some work to the head, which he assumes was done before the machine shop got the block and head as it's not listed on the paperwork. I asked about a head gasket and he said the buy included a FelPro gasket set that had been opened for the valve seals. I asked if he would be interested in a stock steel head gasket which would raise the compression ratio to maybe around 10 to 1 (my guess). He bought one as I have several spares. He will be coming back to get an extra 65 ball and trunnion 833 and bellhousing I have as his deal for the Aspen transmission fell through. He saw my triple Weber set-up I have mocked up on a spare engine and his offer was respectably turned down although we might deal on an early Hemi he said he has. He said there will be no racing, just a nice sounding rod that runs decent. He said he's already installed a B Body rear end with a 3.23 gears. So with this new info I'm guessing the recommendation for the cam would be the #31 225/225 @.050 or possibly even something different. Any thoughts are appreciated. |
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| Author: | DusterIdiot [ Fri Dec 09, 2016 5:16 pm ] |
| Post subject: | Yep... |
Quote: So with this new info I'm guessing the recommendation for the cam would be the #31 225/225 @.050 or possibly even something different.
Yes, with the shim gasket he will be up to about 10.03:1 SCR and an 8.03 DCR if he centerlines it as I describe, based on the new information... he will have to make sure that both the deck and head mating surfaces are very flat before using the shim gasket.With a good 4 barrel and headers that will make a very nice combination...in a light rat rod... it will be fast....and fun.... if he does the 833 non OD transmission with 3.23's it will work fine.... if he decides to use the OD transmission the OD gear will not be very useable unless he goes for a set of 3.55-3.91... the non OD will also have an acceptable rpm drop on upshifts, the OD will need a bit more RPM to keep things in the mains in higher gears.... FYI. |
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| Author: | 65 dartman [ Tue Jan 24, 2017 12:47 pm ] |
| Post subject: | |
New Update: Got a call the other day from the wife of the guy I was helping with the cam selection. He suffered a massive heart attack a couple of days before Christmas and passed away. She found some of the paperwork the other day about the motor with my name and number on it so gave me a call to see if I was interested in the motor. She said the guy helping her get rid of everything said the motor is completely disassembled. I will be picking everything up this coming weekend. |
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| Author: | DusterIdiot [ Tue Jan 24, 2017 5:45 pm ] |
| Post subject: | Sorry.... |
Sorry to hear that and my condolences on the loss of another enthusiast. Hope the transaction goes well for you. It is better to help out their life partner than to see them just call the junk remover and it all goes into the scrap pile... |
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| Author: | 65 dartman [ Fri May 12, 2017 2:01 pm ] |
| Post subject: | |
Finally, an update: I finally was able to make it down to look at and pick up the slant stuff a couple of weeks ago - For the most part the lady's schedule didn't match mine. The guy helping her sold pretty much everything else except the slant stuff. I would have been interested in one of the early Hemi's but that's the way it goes sometimes! But anyway, I now have the block, crank, head, new 30 over pistons already installed to the rods, steel head gasket I sold him as well as the early A 833, oil pan, timing cover, other odds and ends for the engine and new/re-ground hydraulic cam, pushrods, lifters, etc. I assumed since the paperwork said it was an 80's motor that's what it was. The bock and head are mid 70's vintage - casting number on the block is 2806830-6; head is a drool tube head (forgot to write its number down). the crank is a forged crank I figure from the same block. The cam is an Oregon grind #31 with a lobe separation of 108, lobe centerline intake 102 exhaust 114, which is what I passed on to the gentleman from DI. OK, got a couple of questions that I'm not 100% sure about: In re-reading DI's comments about the cam, should it be degreed at 104 on the intake since the head does have 1.70/1.44 OS valves, has had some mild porting done, and from the specs, it appears that the motor should have at least 10:1 SCR. From what I read in searching this, the hydraulic rockers, pushrods and lifters should work just fine in a non-hydraulic motor. Am I missing anything else I should be aware of? The plan is to use this motor in my 65 Dart wagon with my non-OD early A 833. My rear end could be an 8.25 with 3.21s or an 8.75 with either 3.23s or 3.55s in it. No racing, just a cruiser with 20/30% stop and go and the rest highway, |
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| Author: | DusterIdiot [ Fri May 12, 2017 4:37 pm ] |
| Post subject: | Yep... |
Quote: My rear end could be an 8.25 with 3.21s or an 8.75 with either 3.23s
Either will work great for street and cruising.... If you aren't particular about your mileage then the 3.55's would make for a lot of fun but will wind a little higher if doing a stint on the highway.....One other item to be concerned about, if the current engine in your car is a pre-68, then you will either need a 1968-1987 flywheel for the crank on the new motor, or your will have to have a machine shop hone the centerbore in your current flywheel to fit the late crank... Make sure to loctite your crankflange to flywheel bolts, you're going to make a bit more torque than the stock engine.... |
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| Author: | 65 dartman [ Fri May 12, 2017 6:07 pm ] |
| Post subject: | Re: Yep... |
Quote: Quote: My rear end could be an 8.25 with 3.21s or an 8.75 with either 3.23s
Either will work great for street and cruising.... If you aren't particular about your mileage then the 3.55's would make for a lot of fun but will wind a little higher if doing a stint on the highway.....Quote: One other item to be concerned about, if the current engine in your car is a pre-68, then you will either need a 1968-1987 flywheel for the crank on the new motor, or your will have to have a machine shop hone the centerbore in your current flywheel to fit the late crank... Make sure to loctite your crankflange to flywheel bolts, you're going to make a bit more torque than the stock engine....
There is no engine/transmission in the wagon currently and since I have 3 early flywheels, it should be no problem to get my machinist to take care of the center bore in one of them. Good tip on loctiting the flywheel bolts. I hope to start assembling this motor soon.
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| Author: | Rick Covalt [ Sat May 13, 2017 5:07 am ] |
| Post subject: | |
Don, PM me your address, and I will send you a locking ring for you flywheel bolts, for the parts you gave me a while back. Rick |
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| Author: | 65 dartman [ Sat May 13, 2017 7:16 am ] |
| Post subject: | |
Quote: Don, PM me your address, and I will send you a locking ring for you flywheel bolts, for the parts you gave me a while back.
Hi Rick - I have one that I bought from you quite awhile ago. Maybe I'll be able to use it if I get off my tail, get the motor and wagon done! Thanks for the offer though!Rick Don |
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