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Re-grinding cams
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Author:  1930 [ Tue Jan 28, 2014 5:59 pm ]
Post subject:  Re-grinding cams
Oregon cams is a name I found on this forum as having done work for at least one slant six member. I called them this evening and they told me that they could re-grind my new cam ( still inside my engine at this point ) into whatever profile I would choose for 75 dollars ( give or take ) plus shipping.

Any thoughts/opinions on this?
Author:  mattelderca [ Tue Jan 28, 2014 6:25 pm ]
Post subject: 
Don't forget to get new lifters. Sounds like a deal to me!
Author:  DusterIdiot [ Tue Jan 28, 2014 6:49 pm ]
Post subject:  Yep...
They can regrind the lifters too at a few bux a lifter...they support our habit and work closely with a fair amount of us within driving distance of their shop.

-D.Idiot
Author:  Aggressive Ted [ Tue Jan 28, 2014 9:06 pm ]
Post subject: 
Go for it! I have one of their 791 cams thanks to DI. Before I got it, I had my original cam reground at Delta Cams per the specs below in Tacoma if you live up here. It's a torque cam for tall gear ratios and tall tires and excellent mileage.
Author:  1930 [ Wed Jan 29, 2014 2:53 am ]
Post subject: 
Great, sent a P.M to Doctor Dodge, am awaiting a response. Is there any calculator avail to me ( and where would I find it ) that I can put in some numbers from my vehicle and it will spit out the absolute best grind for my truck and what I would like to do with it.

I am looking at sites like comp. cams and evidently they are only going to use my numbers to show me the closest best cam that they offer, If I can get this custom grind made than I know I am not held back by anything such as what is avail and re-popped.

I spoke with Ken last night at Oregon cams and although he is all the way on the opposite side of the Country if you guys have dealt with him and know that he does good/accurate work than the shipping is not an issue with me.

If any of you guys has someone locally that is closer to Florida than please let me know!

Id rather go with a trusted facility than one near-by me just cause its near-by.

Although I did not just out-right ask Ken did not give me the impression that he had any sort of cam calculator and he did admit to being not so computer savvy when I asked him for some possible specs he could recommend and then possibly e-mail me.

I am checking out the engine Faq ect but and I might just be confused but I am assuming that my truck and every vehicle is different, because of the weight of my vehicle and tire size/gear ratio Id like to optimize on this cam swap.
Author:  Aggressive Ted [ Wed Jan 29, 2014 8:42 am ]
Post subject: 
Someone asked the same question the other day. For a truck or heavy car and DI mentioned the cams, My 254 from Delta, Doc's RV10, and Comps 252 and I am sure Oregon has a similar cam, just look at their matrix under CAMS in the Engine FAQ. All those cams build torque at low rpm to move your vehicle. These cams have a short overlap and build more cylinder pressure. Racing cams have more overlap and develop power at a higher rpm. You don't want that for a work truck.

So look for a moderate lift, short overlap and increase your compression (at least 9 to 1) and recurve the distributor.
Author:  Doc [ Wed Jan 29, 2014 10:24 am ]
Post subject: 
Quote:
Great, sent a P.M to Doctor Dodge, am awaiting a response. Is there any calculator avail to me ( and where would I find it ) that I can put in some numbers from my vehicle and it will spit out the absolute best grind for my truck and what I would like to do with it...

...Although I did not just out-right ask, Ken did not give me the impression that he had any sort of cam calculator and he did admit to being not so computer savvy when I asked him for some possible specs...

...I am checking out the engine Faq ect but and I might just be confused but I am assuming that my truck and every vehicle is different, because of the weight of my vehicle and tire size/gear ratio Id like to optimize on this cam swap.
You ask a common question that has no easy answer. (sorry)

The first place to start is with a Dynamic Compression (DCR) calculator, like the one on the KB website. Understand the relationship between Intake valve closing point and DCR and that will help with choosing the "best" cam. Getting to 8.0 DCR with your combo is a great "first step.

There are many other factors involved and lot's of "math" to do in order the find the "best" cam but the biggest problem is getting all your actual vehicle data to "plug-in" to the formulas.
Things like head port size, (flow cfm) actual converter stall speed, correct vehicle weight, fuel quality, operating RPM (gear ratio & tire size) are all numbers you need in order to get a good "prediction" on a cam grind.

Then the collected info must be compaired to actual cam lobe profiles that are available at a grinder's shop. All cam grinders seem to have their own "lobes" (masters) so more research is needed on those.

All this can be a bit overwelming for the person that just wants the "best cam" for their vehicle.
DD
Author:  Rick Covalt [ Wed Jan 29, 2014 12:27 pm ]
Post subject: 
Many of us on the East Coast have used them and they are great to work with and fast on the turn-a-round time. I have had 4 different ones done and all were great experiences. The last one I had done, I told them exactly what I wanted and the master they had was just slightly off from my wishes. But they contacted me and asked my blessing on it before they proceeded. Good company to work with!

Rick
Author:  DusterIdiot [ Wed Jan 29, 2014 4:21 pm ]
Post subject:  x2!!!
Quote:
The first place to start is with a Dynamic Compression (DCR) calculator, like the one on the KB website. Understand the relationship between Intake valve closing point and DCR and that will help with choosing the "best" cam. Getting to 8.0 DCR with your combo is a great "first step.

There are many other factors involved and lot's of "math" to do in order the find the "best" cam but the biggest problem is getting all your actual vehicle data to "plug-in" to the formulas.
Things like head port size, (flow cfm) actual converter stall speed, correct vehicle weight, fuel quality, operating RPM (gear ratio & tire size) are all numbers you need in order to get a good "prediction" on a cam grind.

Then the collected info must be compaired to actual cam lobe profiles that are available at a grinder's shop. All cam grinders seem to have their own "lobes" (masters) so more research is needed on those.

All this can be a bit overwelming for the person that just wants the "best cam" for their vehicle.

Doc is right, although some of us do have some software that when we have time can take your data and "run it" and help dial some theorhetical things in...that being said...90% of us are mechanical cam users as they have less "front end" set up with the price to be paid in having to lash them every so often (but at least you know when to do it and can keep an eye on lobe wear if something goes wrong)...So I have very limited experience in picking a hydro cam (I actually have a high compression engine in mothballs that I was installing a very large juice cam into as a learning process to working with one...)

So if it seems a little overwhelming, you can post your overbore, deck height (how far down the piston is from the deck of the block at TDC), then we can guide you through doing a CC of your head (for calcs and to see if a bit more needs to be taken off to get your goal)...that would get a static compression ratio...then we can compare some common cam profiles and use their info and your SCR info to get a DCR, then you can put it all into action...

-D.Idiot
Author:  1930 [ Wed Jan 29, 2014 4:45 pm ]
Post subject: 
Ok thanks alot guys, thanks for the info and at this point I will digest it and see what might be next for me.

I think this weekend I will get access to the cam and see how far off it is assuming still it is off.....assuming it warms up that is.

Ill be sure to post pics if I get that far
Author:  Doc [ Wed Jan 29, 2014 5:13 pm ]
Post subject: 
Yes, collect as much info as possible from your current engine combination, before purchasing replacement parts or making changes...
Degreeing your current cam, before removal, gives you a lot of good information. (and practice)
DD
Author:  1930 [ Wed Jan 29, 2014 5:48 pm ]
Post subject: 
Quote:
Yes, collect as much info as possible from your current engine combination, before purchasing replacement parts or making changes...
Degreeing your current cam, before removal, gives you a lot of good information. (and practice)
DD
Thats a good idea, will work on that as well.
Author:  1930 [ Thu Jan 30, 2014 3:24 pm ]
Post subject: 
I spoke with Ken again this afternoon and had a few more questions. As far as cam goes this is the profile he suggests, I wanted to hear what you guys thought.

Evidently the cam was designed for the 300 Ford six that someone had in their truck and owner wanted to pull a big horse trailer.

Duration 252 Intake and 260 Exhaust

Duration at 50 Thousands 203 intake 210 Exhaust

Lift 401 Intake 417 Exhaust

Might use a 110 lobe separation but after looking into the stock hydraulic specs and seeing the original 225 cam called for a 105 lobe separation he suggested going with a 108 lobe separation

I cant quite put my finger on how they re-grind the cams to make them larger without adding to the tip of the cam cause obviously if this was done then the cam would never fit in the bore, anyone know how its done and can offer an explanation. Curious

Id like to also understand better how this profile stacks up against the stock hydraulic profile of 255 Intake and exhaust, 188 duration with a 378 lift. 105 lobe separation.

Id like to understand why this new profile would out-perform what was their originally.

According to Ken this cam profile which was manufactured with torque in mind would prob. not affect fuel mileage in the least. Any other thoughts on this?
Author:  Joshie225 [ Thu Jan 30, 2014 3:46 pm ]
Post subject: 
The way a slant six cylinder head flows (rather well on the exhaust compared to the intake) you actually want longer duration on the intake lobe. If you're sticking with stock size valves you want a 107-108° lobe separation. So if we swap the intake and exhaust lobes and get the compression up to a true 9:1 it should run quite well. The increased performance comes from opening the valves farther and having them open longer, but if you don't increase the compression ratio and close the intake valve later you will experience a loss of low speed torque. Board member DadTruck did a lot of work sciencing out the camshaft for his truck so you might look for his posts on the subject.
Author:  Doc [ Thu Jan 30, 2014 4:03 pm ]
Post subject: 
Quote:
... I cant quite put my finger on how they re-grind the cams to make them larger without adding to the tip of the cam cause obviously if this was done then the cam would never fit in the bore, anyone know how its done and can offer an explanation. Curious ...
The cam grinder will regrind the cam with a smaller "base circle".
Doing that will allow for a "bigger" lobe.
The downside is that this can impact the hydaulic lifter's plunger's position or "pre-load". (plunger moves up in the lifter)
You can off-set this by grinding some material off the head and / or block deck surface.
DD

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