If you are changing lift and duration its hardly the same lobe. From just a base flow pov there is a big difference between 1000hp in those f-liters vs your goals.
If you are changing lift and duration its hardly the same lobe. From just a base flow pov there is a big difference between 1000hp in those f-liters vs your goals.
The notion that stroke length is the primary factor in camshaft design is... difficult to comprehend.
The ancient (circa 1971 or so) Toyota 2T-C also had a 70mm stroke. So does a current Ducati Supermono. So does a prewar Alfa 308 straight-eight. These are very different engines, and it's a safe bet their camshaft profiles are equally different.
Please explain why you are trying to reinvent the wheel by focusing on stroke length.
I have just now opened this thread for the first time, and only went to the last page to start, and all I can do is laugh.
Like, I cannot take this seriously, *at all*.
DarkMonohue said:The notion that stroke length is the primary factor in camshaft design is... difficult to comprehend.
The ancient (circa 1971 or so) Toyota 2T-C also had a 70mm stroke. So does a current Ducati Supermono. So does a prewar Alfa 308 straight-eight. These are very different engines, and it's a safe bet their camshaft profiles are equally different.
Please explain why you are trying to reinvent the wheel by focusing on stroke length.
Primary? Where did you get that notion? I also mentioned Alcohol. Which none of those engines you selected used as primary fuel. Finally I mentioned turbo charged.
I should have also mentioned long rod.
Each one of those effect flame propagation, which is what I seek to replicate.
If you know of another engine I'd like to look at their profile. Luckily Offenhuaser , er Meyer Drake, er Drake. Cam profiles are kept as masters. By several cam grinders.
Now I recognized the Offy has 4 valves and thus flows more than a 2 valve. But because of no combustion chambers in the Jaguar the Jaguar will flow more than a typical pushrod 2 valve engine without the obstacle of a piston Dome required in a Hemi engine.
Stock engines have more than doubled horsepower using alcohol and turbo chargers.
Then added more than 100 horsepower with a simple regrind.
Look at what Calvin did. Took a stock 175,000 mile 290 hp Atlas Engine and with simple reground camshafts went to 824 hp. Never opened it up.
DarkMonohue said:Please explain why you are trying to reinvent the wheel by focusing on stroke length.
#JustFrenchyE36 M3
Paul_VR6 (Forum Supporter) said:If you are changing lift and duration its hardly the same lobe. From just a base flow pov there is a big difference between 1000hp in those f-liters vs your goals.
The opening ramp radius, closing ramp radius will be effected. In spite of lift and duration.
If all I was concerned about was lift and duration that's a relatively straight forward math problem.
There are plenty of of people who bolt on a turbo on a stone stock motor and double or more the horsepower. Then pick up more than a Hundred horsepower with a simple reground camshaft.
Our own Calvin did it with the 4200 Atlas engine, taking it from 290 hp to 824 hp. Never opened it up
But a regrind is a relatively cheap change. Why not maximize that gain? It's just a matter of master lobe selection?
In reply to frenchyd :
It seems to me you are putting the cart before the horse.
You are not a camshaft engineer. Your corner cam regrinder is emphatically not an engineer. Neither one of you is going to design a lobe.
Your friendly neighborhood regrinder is going to ask what the valvetrain configuration is, what the engine's physical limitations are, what your intended use of your engine is, and what compromises you are willing to accept. Then he is going to pick a master lobe from his inventory and regrind your cams.
Neither one of you is going to get wrapped around the axle over minutia that you cannot control. You're ordering off the menu here.
You will have more freedom of design if you start from billet or weld your cams up before regriding, but cost will be many times higher. Your budget and knowledge level suggest that approach is unlikely.
I have to unsubscribe from this thread to preserve what's left of my mental health. Good luck.
Power goal and useable rpm range destroy any synergy you may have with stroke and fuel.
imo its easier to design a workable cam once you have a baseline on a particular setup. Do that. I think you will make plenty of power on a twin turbo v8 on stock cams.
In reply to Paul_VR6 (Forum Supporter) :
one UTube Channel Tries to simplify things. Roughly speaking 30 PSI on 5.3 liters on a junkyard LS V8 gets over 800 hp ( dyno ) ( alcohol & Tuned)
Yes different combinations effect actual power. Wheel horsepower, dyno Horsepower, and SAE/DIN horsepower add to the confusion.
Then nobody standardizes dyno tests. Wheel, dyno, SAE/DIN ALL RESULT IN DIFFERENT NUMBERS. Not to mention variables like air density and etc.
Overhead cam V12's running on alcohol is a different kettle of fish. The only thing they have in common is the junkyard build.
I'm looking at our own Calvin who does so well at the GRM drags. He runs an junkyard Atlas 4200 and makes 824 wheel horsepower. About 650? hp before the Schneider reground cams. Both cases the engine doesn't come apart and have about 175,000 miles on it.
I keep going back to the 1970's. When I raced my Black Jack spl. I just bought various cams and tried them. ( pre computer days) the most successful camshaft used the lobes for a 255 cu in Offy. Because it had a 4 inch stroke and direct acting valve buckets. The actual cam was actually used on Ford flatheads for Dry lakes racing. But Bruce Crower set it up for my in line six.
If you look at the lobe from the side it looks like it's got fat cheeks compared to most racing cams which have almost straight shot to the top of a plateau.
Stock both the early 6 cylinder Jaguar and all V12's have the same TeePee looking lobe. Tiny duration and only .375 lift. The prime use of those engines is in big heavy 4 door sedans. The 60,000 that went into the XKE are basically the same and the same for the later XJS, XJ 12, XKEV12. They are all basically the same.
DarkMonohue said:In reply to frenchyd :
It seems to me you are putting the cart before the horse.
You are not a camshaft engineer. Your corner cam regrinder is emphatically not an engineer. Neither one of you is going to design a lobe.
Your friendly neighborhood regrinder is going to ask what the valvetrain configuration is, what the engine's physical limitations are, what your intended use of your engine is, and what compromises you are willing to accept. Then he is going to pick a master lobe from his inventory and regrind your cams.
Neither one of you is going to get wrapped around the axle over minutia that you cannot control. You're ordering off the menu here.
You will have more freedom of design if you start from billet or weld your cams up before regriding, but cost will be many times higher. Your budget and knowledge level suggest that approach is unlikely.
I have to unsubscribe from this thread to preserve what's left of my mental health. Good luck.
Please look at a Ford Flathead camshaft for racing. The Flathead, like the Overhead camshaft is direct acting. Camshaft on valve with only a tappet between. Most of those lobes are copied from the Offy engine. Anyplace that grinds camshafts for Flatheads will use those masters.
There were 121,000 Jaguar V12's made. Slightly over 50% came here to America. How many million Chevy V8's? So yes if you want a common engine or settle for whatever someone wants to grind. Do exactly as you suggest. That is the normal way.
But both Piper and Kent Cams in England will beat whatever you get. But they don't mess with turbo's or alcohol the way Americans do. So if I have them regrind I'll lose that knowledge.
Back in the 1970's it was buy a set of cams try them, buy another set. Repeat, repeat. I eventually wound up using the lobe from the 255 Offy It's not just lift and duration LSA it's also the lobe profile.
I too had a hard time getting my head around that. I mean at 7000 rpm we're talking nano seconds here. Less time than an eye blink ( (typical eye blink 400 nano seconds).
frenchyd said:DarkMonohue said:In reply to frenchyd :
It seems to me you are putting the cart before the horse.
You are not a camshaft engineer. Your corner cam regrinder is emphatically not an engineer. Neither one of you is going to design a lobe.
Your friendly neighborhood regrinder is going to ask what the valvetrain configuration is, what the engine's physical limitations are, what your intended use of your engine is, and what compromises you are willing to accept. Then he is going to pick a master lobe from his inventory and regrind your cams.
Neither one of you is going to get wrapped around the axle over minutia that you cannot control. You're ordering off the menu here.
You will have more freedom of design if you start from billet or weld your cams up before regriding, but cost will be many times higher. Your budget and knowledge level suggest that approach is unlikely.
I have to unsubscribe from this thread to preserve what's left of my mental health. Good luck.
Please look at a Ford Flathead camshaft for racing. The Flathead, like the Overhead camshaft is direct acting. Camshaft on valve with only a tappet between. Most of those lobes are copied from the Offy engine. Anyplace that grinds camshafts for Flatheads will use those masters.
There were 121,000 Jaguar V12's made. Slightly over 50% came here to America. How many million Chevy V8's? So yes if you want a common engine or settle for whatever someone wants to grind. Do exactly as you suggest. That is the normal way.
But both Piper and Kent Cams in England will beat whatever you get. But they don't mess with turbo's or alcohol the way Americans do. So if I have them regrind I'll lose that knowledge.
Back in the 1970's it was buy a set of cams try them, buy another set. Repeat, repeat. I eventually wound up using the lobe from the 255 Offy It's not just lift and duration LSA it's also the lobe profile.
I too had a hard time getting my head around that. I mean at 7000 rpm we're talking nano seconds here. Less time than an eye blink ( (typical eye blink 400 nano seconds).
Hey! You aren't reading/listening again!
If we are still talking about a Challenge car (LOL, you arent.) Then no one that you talk to about grinding cams is gonna know anything about Kent or Piper.
They are gonna look in their catalog and pull out what best fits your engine.
If you are paying full race prepped racecar money, maybe they will listen to you waffle on and on about which is better.
In reply to Mr_Asa :
The car entering the Challenge will have a second life post challenge when I am not limited by budget. Right now I'm solidly under $1000 and there is only a remote chance I'll have enough left to regrind the cams.
However if I do have room in the budget, right now I'm inclined to use my local guy because of cost. Before I do, I'm going to have a clear idea of what will work. Because the cost of regrinding is the same no matter what lobe or specs are used as long as it fits inside the existing cams. I know he still has those Offy Masters because he regularly does Ford Flatheads for local hot rodders.
No I will not use Piper or Kent cams. Round trip air fair and any import duty on top of their premium makes that too expensive.
Crower is the leading candidate who will be grinding them post Challenge. Their familiarity with Group 44 is as close as I'll come to blind trust.
To my knowledge only Isky lists the Jaguar V12 and they offer 5 different grinds only 3 which can be regrinds.
Oh and for those who are concerned about springs. The stock springs should be fine, Isky sells a set that are better. And then if I should decide to go over 10,000 rpm Cosworth sells the same size spring. ( formula 1) Although they buy them so I have another source to ferret out.
Paul_VR6 (Forum Supporter) said:mke said:frenchyd said:Paul_VR6 (Forum Supporter) said:I have a marketplace notification setup for v12, I kinda want one now
Too bad, I coulda brought you one during the Christmas break. I went through PA to pick up my fender flairs.
Should I be looking around for you? Any preference, Pre HE, HE? Running, turns over? Parts? Budget? Looking for a car with it?I wasn't paying any attention to locations and had it in my head Paul was in England until I saw just PA .....30 miles away. I may have just found my new dyno shop
Edit: wait....is there a dyno at the shop or do you have a place you go to?
We don't have one we usually use NGP in Aberdeen they have a dynojet and we get good access.
For the v12 I'd like a car around it, figure it won't run as there is a book called Jags that Run to fix that part.
There is a 610 page free download that goes over the Jaguar V12 and the president of the local Jaguar club just published a free down load on the EFI for the Pre HE.
We're getting into the spring and summer period when prices on complete cars running or not gets silly. Fall and Winter are the best time.
I've always found the best deals on complete cars either by word of mouth or by attending local Jaguar clubs. Typically when they are Advertised , Facebook, Craig's list etc. they tend to be highly overpriced and if you check back later they get much more flexible.
However given where you are located rust free is going to be real hard.*. Do not attempt to "fix" a rusty one. If the area around the windshield or back window is rusty, ••••• don't. The floor/ trunk ? Borrow my Rotisserie and have at it. Suspension mounts, front crossmember? Run away!!!
May I suggest you watch the south western states for rust free cars. Texas to southern California. July August and September are when they sell cheap. The interiors will be shot. ( I lucked out on mine and it had good interior, all it needed was some Leatherique. ) Come back to the rust belt if yours like a good interior.
I have a fb marketplace search saved. As far as I can tell I may be one of the worlds most prolific tuners of heron head cars, mostly by accident. You are definitely over thinking it. John at Dougherty cams would be the guy I would send you to. He does a nice cam for us that makes huge gains vs stock while still giving good driveability on the lower compression cars and works good with alky and turbo as well. I know he has done regrinds but may or may not do yours.
In reply to Paul_VR6 (Forum Supporter) :
Guilty as charged. I always over think things. My job requires a tiny fraction of my brain to do so waking hours I'm thinking. Often about the race car.
When buy then try was the way racing was done I used to find time to watch the way cams were re- ground.
Basically a set of intake and exhaust lobes are set on a pattern bar, clamped together and then traced onto the camshaft with the grinder. Most of the work is in the set up and then checking and re checking.
I suppose the high volume grinders have a machine that does that rather than the hand set up the smaller guys who do it along with other machine shop work.
Most people defer to "experts". But what expert is doing what I plan on doing?
The average buyer of camshafts uses their butt dyno if it feels faster they are happy. Rarely do they actually compare other by racing or even a dyno session. If The Dyno session gives an bigger number they are happy.
The very few that race seldom know what the real reason for their success or failure. It could be the driver, the tuner, dozen or more design features. A combination of some or all of the above.
I did my research on selecting the turbo's. I was careful to ensure they would work where I would race. Now the only thing left is the camshaft. I know my local guy isn't an expert on turbocharged JaguarV12's running E85. But nobody is.
So I have to figure it out.
The big thing is the good cam grinders already have a master that is workable for your setup and no design is needed. This is how we end up with some really cheap cams that work surprisingly well. For you "good enough" is well beyond what's needed.
In reply to Paul_VR6 (Forum Supporter) :
I know of a 73 XJ12 Sedan that needs rescuing. Doesn't run but body and interior is nice.
Sounds like the perfect dumpster fire if it's cheap enough.
In reply to Paul_VR6 (Forum Supporter) :
Lol I'll text you the link.
Edit*
Nevermind it sold
In reply to Paul_VR6 (Forum Supporter) :
That's a classic elegant car. Solid body is real important. Plus it's got carbs. If you'd rather play with EFI I've got several sets of that I'll trade for the carbs.
yupididit said:In reply to Paul_VR6 (Forum Supporter) :
Lol I'll text you the link.
Edit*
Nevermind it sold
What were they asking for it?
In reply to frenchyd :
$2000.
In reply to yupididit :
Probably a very fair price but not one I'll buy.
Thanks.
In reply to frenchyd :
It solf already. The interior was restored and the body was rust free with great paint. Just didn't run and needed a suspension refresh. 2k was a very good price for the car. If it was an xj coupe I would've been so over it.
In reply to yupididit :
That's a really great price. Doing the interior alone would cost more than that. Is the 1973 still the big grill or did it have the big bumpers? 'Cause the big grill is among my favorites.
As a V12 coupe those are selling for near 10 times that.
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