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Engine Combo Critique
Hi guys, new to the forum. Want a critique to make sure things will be okay with my 383 stroker build. Motor is going in a 69 camaro built for the street weekend cruiser. Goals with this motor is 400+hp, and a nasty idle, 4.10 gears.
Combo is 87 gm truck block eagle B13004L rotating assembly (4.030 bore, 5.7 rod, externally balanced) Pistons are -18cc 0 deck height Stock 64 cc heads (upgraded springs and lifters, stock rockers for now) Comp Cams Mutha Thumpr (235/249 .522/.509 107LSA @ .050) Static Compression Ratio right around 10:1 will this be good for 91 octane and what would be the max rpm you would spin this motor to? Will the flywheel of the original motor work? HP guestimate? |
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why? cam choice? compression? elaborate on your humble opinion
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Human nature is a funny thing, you never know how it's gonna pan out. The story with these rump-rump cams is that some of you fellows like hearing the sound. I'm thinkin' that some of the fellows mistakenly identify rump-rump with power. Ain't necessarily so, McGee.
Most of us old-timers frown on the practice of intentionally making the motor rump-rump by the use of a cam with altered timing points. We've been building motors since the 40's or 50's or 60's or 70's and we never built one just to hear it lope. We always built for max power or max mileage or max low-end torque or whatever and if the lope was there, fine. If the lope wasn't there, fine, as long as the motor performed like we intended it to. Nowadays, some of you fellows want to hear the lope at the expense of power that could have been generated in your motor if you had used the proper camshaft timing. That's all well and good for you fellows, but to us old timers, it sorta seems like posing and we don't much like it. Now, I voiced my opinion on this subject in another thread and was called down by another old timer. He said something like, Don't you remember installing Smittys and port-a-walls and running bigs and littles and loud pipes and it was cool to run around in primer with the wheels painted red"? Hey, that was posing!! Do you remember wearing your hair with a waterfall at your forehead and combing it back into a duck's ***? (called a D.A. in the day) And don't you remember 9" pegs and points and skinny belts and your collar turned up in the back and a pack of Luckys rolled up in the sleeve of your T-shirt? Hey, that was posing!! I admitted that yes, we were posers too, back in the day. I guess it will happen with every generation. Each will have their likes and dislikes, no matter what the whole of society says about it. Canzus is a grumpy fawker by self-admission, but he makes the point that you may not make as much power with a thumper-type cam as you could with matching the cam timing to your static compression ratio and choosing a cam that will pull the load in the range that you want it to. Now you know. Last edited by techinspector1; 02-13-2012 at 11:48 AM. |
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Quote:
I got a guy a friend of mine right now has a 68 corvette with a factory 390 Hp 427 with a 4-speed and he came up to me the other day and wanted to know if i would put the big mutha thumper in it i said why would you want to do that to your engine, he said quote i'm not worried about the performance i just want a mean sound that rumps rump rump.he want it to sound mean. I for the love of god have never understood why someone would be more worried about the sound over performance. I told him that engine is fine just the way it is IMHO that he was just going to ruin it that it would be a big let down after chancing it like that. Don't get me wrong i like a good sounding engine and the best ones had matching parts in them and performed when the old radical sonud of the non matching parts and the big cam was just that sound and down the road they were dropping valves among other thing going wrong with their engines i have seen it way to many times through the years. But i guess it comes down to it is your money and your ride and i really do hope you figure it all out someday. Well i have vented enough on this subject. Thank's Richard for getting me started I could go on. Cole
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Quote:
I was President of Viking Customs, a club with about 40-45 members. We had baby blue waffle cloth jackets, but other than that, you are right on the money. I remember one of the fellows yanked the body off his '49 Ford and went screaming past the high school burning rubber like crazy. He was riding on a milk crate attached to a board and driving just a chassis and running gear. No sheet metal. No exhaust system, just the open ends of the flathead manifolds. Waaaaaay cool, or so we thought at the time. Like WOW, man. |
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Bogie,
I do believe the heads are swirl ports. There the 193's. I will be putting a set of aluminum heads on it, not just right yet. Pistons are Keith Black 135 pistons says they are 18cc volume D- Cup. Am i going to be okay? |
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87 was a break year . Need the casting number off the block and you to look at a few things . Does it have the three bosses on the lifter valley? Are they drilled and tapped ? Is it machined and drilled for a retainer plate where the cam goes in ? If so put a hydraulic roller in it . Then you dont have to worry about cutting the cam lobes off on break in . The ramp speeds are also quicker . The 193 heads have a big intake runner and make great torque low , but wont work with your large cam choice cause they just wont flow were that cam makes power . Thet run out of steam about 4500 rpm due to a divider wall in the intake port . I would suggest a Vortec or world product or the aluminums you mentioned , depending on which ones . The dishes will work fine for pump gas , but as mentioned pay attention to the quench . I am also not a fan of external balance . With internal balance the balancer and flywheel will be nuetral so if one fails you can replace it with another without rebalancing . I also prefer a minimum of 5.85 rod due to rod angle , but thats just me . Im a nitrous user .
The sound of the cam is a side effect of making power at a given rpm range . I cant help with the cool sounding cam thing . I have a similar combo to this , 91 truck 4 bolt main block , Eagle forged lightweight series crank , Crower sportsmans , SRP pro series dish pistons , XR288hr cam , double roller chain , GM Fastburn heads , edelbrock rpm airgap , speed demon 750 6530 MSD box . This combo makes good power and has just enough vacumm to run power brakes . Last edited by Hotrod 80; 02-13-2012 at 09:10 PM. |
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