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11-20-2015, 01:32 AM | #1 |
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High compression question.
Does high compression (155lbs) require a step hotter plug, or should a standard plug do the job? How about the distributor advance plate setting? More advance or less advance? This is a stock C59A with milled heads.
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11-20-2015, 01:45 AM | #2 |
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Re: High compression question.
Why a hotter plug ?
If youre running the engine harder a colder one maybe ? |
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11-20-2015, 02:32 AM | #3 |
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Re: High compression question.
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11-20-2015, 02:39 AM | #4 |
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Re: High compression question.
Start with the standard ones and check how they act then.
Depending on if you run it hard and get issues with selfignition you might need colder ones. You can swap in colder plugs untill you get issues with fouling or hotter until you get selfignition. Somewhere in betweeen is where you want to be ! |
11-20-2015, 02:57 AM | #5 |
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Re: High compression question.
High compression you want less total advance.
Martin. |
11-20-2015, 06:47 AM | #6 |
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Re: High compression question.
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Yes, higher compression ratios usually need slightly less spark advance than lower ratios. This is especially true at high speeds. |
11-20-2015, 07:48 AM | #7 |
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Re: High compression question.
My 40 coupe has 160# cranking compression, I built that engine 40yr's ago, got over 100G on it. I had a lot of pinging problem, running crab dist, I kept welding up the advance slot weights to about 17-18* total, played with vacuum retard, screwed down about half way. Run the cheap gas, no ping, will scream to 5000 like nothing. Walt
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11-20-2015, 09:32 AM | #8 |
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Re: High compression question.
My thinking is that the engine will never need more than factory advance max degrees.
It may need to come in sooner or later but never above max. The basic configuration of the engine never changes , ie: same valve type, and engine design. Do anything ya want but its still a flathead... Heres an extreme flathead from Ken Makuch https://www.facebook.com/ken.makuch....type=2&theater 180 mph with no blower!!! Twin 4 barrells 780 cfm each...... |
11-20-2015, 10:27 AM | #9 |
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Re: High compression question.
That's one nasty sounding flathead.
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11-20-2015, 11:12 AM | #10 |
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Re: High compression question.
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11-20-2015, 03:54 PM | #11 |
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Re: High compression question.
The curly pipes must quiet it down a lot.
For making that much hp, it sure isn't very noisy. Even as it is, those guys are going to have ringing ears without ear muffs. |
11-20-2015, 04:36 PM | #12 |
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Re: High compression question.
Tim, it's the same engine with the 4 97's, I've had everything on top from 2 carbs-3carbs- 4bbl, McCa Super charger, I did break a second ring land on one piston at about 50G, I couldn't get one 1/8 piston so I bought a new set, the new set was .002 bigger so I just hone .002 and had a new engine again, It has the same main bearings for 40 years, I did put a new set of rod bearing in with the pistons. I've done a lot of long trips, T5 trans and 9in. rear with 3:50 gears, 60mph 2000rpm, that's probably saved the engine on long trips. Walt
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11-20-2015, 05:32 PM | #13 |
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Re: High compression question.
what are you guys doing to get such high compression numbers? please be specific, if you would.
thanx, tom |
11-20-2015, 06:22 PM | #14 |
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Re: High compression question.
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11-20-2015, 06:51 PM | #15 |
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Re: High compression question.
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11-20-2015, 07:28 PM | #16 |
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Re: High compression question.
276ci, 3-5/16x4, not relieved, 40thou piston clearance, this is in my 40. I have 2 of these engines, I have a 3rd, in my dragster, 286ci, less comp ratio, big reliefe , 2.600 intake valves, Potvin 425 cam, this engine is a screamer. I have one 276 on my test stand for sale, I,ll post it on the sell section. Walt
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11-20-2015, 07:33 PM | #17 | |
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Re: High compression question.
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How much horse power is that thing making? Sounds quite fit. Martin. |
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11-20-2015, 07:39 PM | #18 |
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Re: High compression question.
I thinks its 300 horse power , first time i have ever heard about 300 HP with out a blower. Theres a couple threads on the hamb board about Ken and this engine . They have done a ton of camshaft work etc...
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11-20-2015, 08:11 PM | #19 |
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Re: High compression question.
Cool, thanks for the info. I'll have a sniff around the HAMB.
Martin. |
11-20-2015, 08:48 PM | #20 |
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Re: High compression question.
Although some may disagree, I don't believe 200 HP is obtainable with out extensive block modification. Going back ti the 50's when guys like Bob Francisco and Ray Brock built an dynoed an engine in Hot Rod nag they couldn't get over 200 hp with out Nitro. In a week or two a 294 with Eaton blower will be on the dyno in CT. looking forward to the results.
As for max advance in a flathead: this is a trick question. Max advance depends on the combustion chamber configuration at WOT and Cruise load. I and others have found that between 18 and 20 is max at WOT and even a slight retard at hi revs. In cruise is another problem, Here the AF and cylinder turbulence and spark plug location will determine the amount of advance is needed. Yes this can be averaged out for a so-so advance curve that works OK, because the factory tuning methods of the 40' through 80's did it that way. Today we hav engine management systems that can improve on them and have a cleaner running to boot. We just have to have an open mind, and it's not just "good enough" We can make it better, we just have to thimk??? |
11-20-2015, 09:41 PM | #21 |
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Re: High compression question.
I have a cheapo compression gauges that reads high. I mean, "astound your friends" high. I've demoralized my son showing him my '93 Tercel 4-banger has higher compression than his 300hp Nissan.
I never lend it out. Lonnie |
11-20-2015, 10:10 PM | #22 | |
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Re: High compression question.
Quote:
There are formulas you can find on the internet that you can plug various parameters into and find horsepower required to go so fast in a car with a certain drag coeffecient and traction. If you don't know certain parameters, there are"help" features that you can guestimate with and come pretty close. Oh, and in the HAMB thread of 3 years ago or so, he showed a picture of the supposed cam he was running and I made comment that it was a roller. He said it was a flat lifter grind. He either got his pictures mixed up or he was lying. The picture was of a roller cam. Aside from that, 300 hp is quite possible (definitely not cheap) with either a flat lifter or roller cam. |
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11-21-2015, 01:08 PM | #23 | |
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Re: High compression question.
Quote:
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11-21-2015, 06:07 PM | #24 | |
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Re: High compression question.
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Not a good way to do it engineeringwise. The assembly when laid out on a table looked similar to a horseshoe. |
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11-22-2015, 07:56 AM | #25 |
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Re: High compression question.
The horse-shoe roller lifter, or at least what we called "horseshoe lifter" was popularized by Racer Brown many years ago. It does not use a connecting bar to hold the lifers but rather the sides of the lifter body extend slightly beyond/below the diameter of the cam follower and become the guides to maintain the lifter in line with the lobe, by using the lobe as the central point. Of course a failed valve or spring causes a problem. But then that is a problem no matter which or what style lifter is in use.
Unblown and without "power adders" such as Nitrous or chemical fuel enhancements or valve layout changes, 300 HP is far removed from reality. And, I do not care how much is spent. |
11-22-2015, 10:23 AM | #26 | |
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Re: High compression question.
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Quote:
I agree , thanks for the lifter thoughts.... |
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