01-19-2020, 06:25 PM | #1 |
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Which Cam
I am building a 81A block. Cam choices, because I have them, Schneider 248 and a Isky 77B. Car is a 40 sedan with 3/78 gears, Merc crank, single 97. Stock iron heads. I know the 77b is almost as stock, but would someone who knows these cams describe the nature of the 248 compared to the 77B?
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01-19-2020, 06:49 PM | #2 |
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Re: Which Cam
Well, the duration is the same for both 220 degrees at .050 -- the 77B only lifts about .325, while I believe the 248F lifts .350. When I sent to Schneider's site - they showed two different lift options . . . one about .320 and the other .350. Truth be told, I'd probably not run either of them - they are very mild cams (but hey, I know - you have them). I'd much rather see you use an Isky 1007B - would sound good and run well . . . and to me, I like BOTH in a period car.
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01-19-2020, 07:19 PM | #3 |
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Re: Which Cam
Any one that has ever “honesty “ used one would recommend an L-100
Cheers Tony |
01-19-2020, 07:56 PM | #4 |
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Re: Which Cam
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01-20-2020, 10:00 AM | #5 |
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Re: Which Cam
Having used "Many L-100 cams, I can "Honestly" say: they don't work very well in a relatively stock engine. Having too mucj duration and overlap, which kills low end torque. These cams need some displacement and compression o replace that. They run well in bigger engines. However if you want a beter cam try the Isky 1007B. But I gess if you already have these other cams, either on should work OK
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01-20-2020, 11:51 AM | #6 |
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Re: Which Cam
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01-20-2020, 01:49 PM | #7 |
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Re: Which Cam
Thank you for your advice and perspectives.
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01-20-2020, 06:37 PM | #8 |
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Re: Which Cam
I would think any cam would run well in a 284 ci engine. But in a stock engine you have to be conservative.
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01-20-2020, 08:36 PM | #9 |
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Re: Which Cam
I understand Ol Ron's comments much better after reading the first half of JWL's book "Flathead Facts".
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01-20-2020, 08:48 PM | #10 |
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Re: Which Cam
I have the 1007B, but it will be a few months before I can get the engine up and running. Hope it works on a stk engine (C59A) with just a 0.060" overbore.
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01-20-2020, 11:52 PM | #11 |
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Re: Which Cam
The best modification you can make to a stock or mild modified engine is piston to head clearance. This increases the turbulence in the chamber and better combustion. This improved fuel mileage and better throttle response. Plus, it's not that expensive.
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01-21-2020, 04:03 AM | #12 |
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Re: Which Cam
Good to know. I have the factory relieved heads. I think compression ratio is about 7.3:1 with my 0.060" o reborn according to the big chart someone made a while back.
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01-21-2020, 07:53 AM | #13 |
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Re: Which Cam
Those charts are for reference only. You actually have to measure the chambers to determine the CR. In my book I measured a dozen or so heads and they were all over the place. Another consideration is the difference between Static and Dynamic compression. This is determined by the closing of the intake valve. An L-100 cam drops an 8: 1 CR to around 6:1. Good reason to have more cubes.
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01-21-2020, 12:44 PM | #14 |
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Re: Which Cam
Post was off topic . . . so I deleted it. Sorry bout that!
Last edited by Bored&Stroked; 01-21-2020 at 03:43 PM. |
01-21-2020, 01:43 PM | #15 |
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Re: Which Cam
Ok guys and gals, a simple attempt to gather info to assist me in choosing between two cams, seems to have become a tutorial on building an engine. I'm sure many need and value this information, but I am familiar with the issues brought to light and familiar with building V8 flatheads. My only request, was for a cam comparison. Can we stick to the question asked.
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01-21-2020, 05:13 PM | #16 |
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Re: Which Cam
OK. I don't see why anyone, after looking at the specs of all cams available for your engine, would even consider the 77B. I went through this a couple of years ago when I was deciding whether to put an Isky MAX-1 in the '51 Merc engine I put in my '51 Ford Club Coupe. After a bunch of research (including this site : https://www.tildentechnologies.com/C...erformance.htm, I decided to keep the stock 8CM cam. From the overall experience since then, I believe I made the correct choice.
Also, I am in complete agreement with "Ol' Ron" about taking care of the heads FIRST. |
01-22-2020, 11:00 AM | #17 |
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Re: Which Cam
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01-22-2020, 11:40 AM | #18 |
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Re: Which Cam
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01-22-2020, 12:19 PM | #19 |
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Re: Which Cam
Yes, you could check it, but why do it twice. Suggest you view my tutorial on the original Techno site where i moderated for Bill.
https://web.archive.org/web/20160318...g/clayhead.htm Wait for photos to load, as they are archived. |
01-22-2020, 02:17 PM | #20 |
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Re: Which Cam
Russ/40. Great information on measuring valve to head clearances. Thanks for posting it.
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