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mikeT
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Working on my 292 project i have a Howards cam #290862-10 How do you think it will work in my combo? fenderless truck hot rod will weigh 2700lbs? ford 8.8 with 4.10 posi rear T5 trans 292 engine .040 over, zero deck flat top piston's with felpro or best head gaskets c2ae rods with arp bolts Main studs with windsor windage tray deep sump pan , chopped up a scruby sb deep wide sump pan .Fitted sump to y block truck pan, modified pickup for 3/8" clearance from bottom of pan, holds 8 qts. gerotor oil pump new Heads are CT1E will be fully ported , milled to 70cc chambers. Will have manley stainless 1.85 intake and 1.55 exhaust valves installed comp cams springs and hardware Static compression ratio should be 8.7:1 to 8.8:1 ? Intake is edelbrock 257 ported per Joe Craines advice will use holley 2x4 sniper fuel injection MSD ignition Headers into flowmaster mufflers camshaft is 238 @ .050" I &E lift is .350" lobe lift, rockers are Barker ,Approx. 1.5 ratio lash is .022" valve lift should be approx..507" at valve with .018" hot lash will check for piston to valve clearance . Would this run on pump gas regular or premium? going to be a fun street rod to play with on weekends .
thanks for the info 55blacktie It shows dynamic compression at 7.24:1
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55blacktie
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Go to gofastmath.com to calculate dynamic compression ratio. Personally, I would want more compression with your cam. Ideally, you want your dynamic compression to be close to 8:1. With flat-tops, 70cc heads, and 238 duration @ .050, you will be considerably lower than that.
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charliemccraney
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I agree, it needs more compression. Build it to take advantage of premium fuel. Do not get caught up with the cost of premium fuel. More compression makes it run more efficiently (and with a cam like that, makes it less sluggish from a stop) which will translate to higher mpg, if that's even much of a concern for a hot rod. I think the 8:1 dynamic is about the limit for pump gas and gives a bit of a cushion for a bad tank of premium.
Lawrenceville, GA
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55blacktie
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I've read Tim McMaster's article on porting the C1TE heads. It makes sense to me, if you already have the heads, and you are capable of doing all of the work yourself. On the other hand, I got a pretty good deal on G heads, which should flow as well as the modified C1TE heads, but without all of the work. With a street port, I'm inclined to believe the G heads will outflow the ported C1TE heads. G, 113, and Mummert's aluminum heads seem to be the preferred heads, if you are looking to increase performance. 411 heads, with their larger combustion chambers, are desirable on supercharged engines.
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55blacktie
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Sorry to be beating this into the ground, but you did ask. I looked up CS Cams description of your cam. The rpm range is 2800-5400, which seems to lack both low and high end. Clay Smith also recommends a static compression of 10:1+. You've given considerable thought to your build, but I think you can find a cam that is better suited to your combination. Something with less duration and overlap will raise your dynamic compression ratio. Another option would be to use domed pistons.
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55blacktie
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Well, I got everything right but the brand, sorry. I did look up the right cam, but thinking Mummert, I said Clay Smith, not Howards.
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mikeT
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Yes, I have the heads and will be porting them myself. Wish Mummert still had the forged pistons with .100" dome available? Cant justify 850.00$ for custom pistons on this project. I have read the Ted Eaton engine build with a similar camshaft ,it had a dynamic compression ratio that was close to this and it seemed to run good?
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Ted
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I took a look at the specs on that Howards camshaft and it does look like a good candidate for your combination. I will have to disagree with the basic rpm range that’s listed for it though as it should indicate a wider rpm band. That camshaft is similar to the one I use in the 312 dyno mule which is a Crower Monarch 280-F which has a 280° advertised duration but the same 238° duration at 0.050” and ground on the same 110° lobe centers. I’ll suggest checking the valve to edge of piston bore clearance as any significant milling of the heads will bring the intake valve dangerously close to the cylinder wall at full lift. Small notches at cylinder wall edges under the intake valves will solve any clearance issues for that but be sure those notches stay above the top ring area of the cylinder. Howards camshaft 290862-10 Year:1955 - 1963 Make: Ford Engine: 292-312 Camshaft Type: Mechanical Flat Tappet Basic RPM Range: 2800 to 5400 Valve Lift Intake: .515 Valve Lift Exhaust: .515 Duration Intake: 265 Duration Exhaust: 265 Duration at 050 Intake: 238 Duration at 050 Exhaust: 238 Lobe Separation: 110 Intake Centerline: 106 Firing Order: 1-5-4-8-6-3-7-2 Quantity: 1 Each Country of Origin: United States
 Lorena, Texas (South of Waco)
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mikeT
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Thanks Ted!
would you suggest advancing or retarding the cam ? The cam card says the intake closes at 45 degrees
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Ted
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mikeT (1/21/2021)
Thanks Ted! would you suggest advancing or retarding the cam ? The cam card says the intake closes at 45 degrees That 45° number does not mean much to me without the other numbers. If using the lobe centerline method to degree in the camshaft, then my recommendation is to install it at 105°-106° intake lobe centerline which is 4-5° advanced. This is assuming the timing chain is new. As the chain wears in, the camshaft will retard accordingly. When I run the numbers through my spread sheet, the intake valve should be closing at 58½° ABDC with 4° of advance assuming the advertised duration is figured at 0.020” lobe lift.
 Lorena, Texas (South of Waco)
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