Discussion in 'general muscle car related info' started by hotrod coupe, Oct 26, 2016.
Yeah Grumpy is dead on here
is the rear cam plug reuseable after removal to replace cam bearings. any preferences to suggest as I would go with cleavite 77 for cam bearings. I am also considering oil return stand pipes since I have roller lifters but there seems to be pros and cons with this.
I like king bearings personally there are a bunch of options out there some companies have there products sold under other names at a cheaper price but any quality bearing should work.
inquired with howards about 278/278 cam 180885 with afr heads should I use 108 or 110 lsa and was recommended to use 278/286 cam 180325 @110 lsa. just from reading theory, heavy visard influence, I thought that with better flowing heads and exhaust a single pattern cam was better. if I am wrong please direct me to proper links.
the longer exhaust duration and wide LSA is an advantage if the exhaust is restrictive.it provides more time for the mass of exhaust gases to exit the cylinders,keep in mind its that properly timed exhaust that drags in the following intake charge.
if your using open long tube headers with the proper length primary and collector design,to match your displacement ,compression ratio, and cam timing, longer exhaust duration rarely provides a useful advantage.
read through these links, and sub links,
yes it may take a couple days,
but after understanding how and why things work,
the info is sure to save you a great deal of wasted time,
and a bunch of wasted money.
It depends what you are trying to achieve David Vizard formula would have you put a 108 LSA in a 350 with a 2.05 and 106 intake valve in a 383 with 2.05 intake valve. I went down this road with my first cam selection cam here asked Grumpy to lead me to the light and he did I used the Vizard formula ran the most aggressive cam to meet the formula as possible the car was a beast. I have also came across new light as my studies have gotten deeper and have talked to others cam people such as Mike Jones and other custom camshaft manufactures. It has allot to do with a complete combo of things and needs here. Horse Power is a derivative of torque and rpm and some times spreading the torque which happens when you add duration and spread the LSA. My take on it is this there are allot of different opinions on this and it is argued up and down the internet with cars running bad ass with both setups so you can run as you feel. So I had some conversations with people on this including the gentleman who designed those AFR heads. I ran a 274/274 246/246 on 108lsa solid with .535 lift. It was a true race cam and it acted like one I had to run a vacuum canister for my brakes and it was very chuggy at lower rpm not something that is too nice if you are on a highway trip in OD enjoying going to larger car show per say. Also head technology has increased a large amount so there is less need to use a camshaft to band-aid head issues. Big question is what rpm are you going spin that engine to and how often? Be honest with yourself here because street cars with good road manners and full racing cams do not get along well. There is a reason most tight LSA cams are in the track section of cam catalogs and most street strip cams sport a wider LSA. Track cars use a specific RPM range that it needs maximum power at my ISKY high-Rev would 3500 up 6500 really give you strong power which was maximum power for that area as Vizard states. Which tuned for a certain circle track would be perfect pull hard out the corner and accelerate down the strait. It would pull good even from mid 2500 area but not like the 3500 and up. This is the area you would be pulling in a corner after breaking lowest rpm. So a street/strip or road race cam is totally different you want spread power over a larger rpm not a smaller peak power band to minimize lap times or quarter mile times. So be honest ask yourself if you want to race or if you want a street car that is nastier then most and if 10-20hp is worth that street ability. When I discussed my camshaft selection with the gentleman who chose my cam for me this year I told him the Isky was nice but I wanted a cam that would be a tad better in street ability. So ask yourself which is more important cause some people it gets old when it is work to drive the car allot of people want a car you can throw it in drive and go. Not have to check the gauges and make sure all is in harmony and do extra procedures and keep extra maintenance. Again this is my take and opinion remember the 700r4 has a lockup converter you can lock up to get better highway mileage. I have a 2600 converter I only saw chugging at 1200 rpm on the highway with the converter locked up.
Strictly Attitude points out an important factor here, a street car engine needs too be both totally dependable and drive-able in the rpm range it will spend 96 % plus of its life operating in, rather than the 2%-5% of of the time where peak power is the major goal.
there's a good bit of discussion on cam selection in the thread links posted above and in this thread,I,ll post below, notice the cam selected in that t-bucket engine build up, is far from the most radical cam that could be used, that might fit the application,and there's discussion on the differential gearing intake selection and trans gearing and converter stall speed, and while the cam and heads selected were not (BY DESIGN) the components that would cost the least or produce the best peak power numbers
YET they ARE well matched and can quite easily do two things,
provide dependable and instantly available and impressive torque,
and allow the car to drive without problems on the street,
something, purposely designed into the cars drive-able characteristics,by selecting matched components,
that a much more aggressive cam, that makes a bit more peak power would most likely not provide.
this is a factor that a great many people don,t grasp or understand, and thats correctly matching the combos characteristics to the true intended application, it makes no sense to build a 600 hp sbc that produces peak power at 6700 rpm if your car has a transmission and gearing that restrict its operation to the 1500 rpm-6300 rpm range, yet I constantly see guys read the magazine articles in places like stock car magazine and decide to try and duplicate some 600 hp plus combo they read about on a street car engine build, then they proceed to really screw it up further because they decide that the expensive cylinder heads and block machine work can be ignored to save money, so they substitute much less expensive components and don,t match the drive train and gearing and act stunned and amazed when the combo of mis-matched components runs like crap, gets into detonation issues and surges and bucks at anything under 4500 rpm.
that t-bucket engine should produce just a bit under or over 500 hp,once correctly tuned ,(Ive seen a very similar combo,(on a dyno test)
I built have 473 rear wheel hp,
(thats about 540 flywheel)
(the only major change was a tunnel ram with dual quads)
which in a 2000 lb t-bucket will be brisk performance yet retain decent street
put 2200 lbs (car and driver and 500 flywheel hp in the calculators)
when tapping for front oil galley plugs what size are they, 1/4" pipe thread is too small until you are way back and there is very little to thread on the center galley before the oil passage. are larger plugs used here?
1/4" pipe thread plugs is what I use. And RED Loctite. I agree that the way the newer blocks are machined there,
don't let you start threads until you are in deep. Not a problem on the 2 outer lifter galleries, but the center one can
block oil flow to the front main bearing if installed too deep. I ground/filed a notch in my center plug to prevent this.
Crappy picture, but you will get the idea.
I drill and tap for 3/8" npt
strictly attitude, I gather that 274/274 cam was a mechanical roller with the @.050 duration numbers. looks to me like just where I want to have my power band with a hydraulic roller. approx. 2000-5500 cant find anything in the 274-275 single pattern mass produced. figure I may have a cam ground to what I want. I just need to make shure that I will want what I order.
You do not want to run Mechanical Roller you want a hydraulic roller no point in a under 6500 rpm street engine. My car is going to be more of a race car. Grumpy has found you a good one right there.
it appears that the center galley on my 880 roller block can be threaded with 1/4 npt before the step down in size for the galley bore. it seams slightly larger than the side galleys. is this correct or am I missing something.
I have read that stock hydraulic roller lifters will bleed down above 5000 rpm. I am considering using comp cams 3015 lobe grind 274@.006 224@.050 149@.200 lobe lift.358 valve lift w/1.6 .5728. an aggressive lift, opinions on will this work with the stock lifters
why use stock lifters when there are lots of much better quality hydraulic retro-fit lifters with significantly better potential rpm capability for not much more money? even if you were going to pay $200-$300 more for the linked hydraulic roller lifters, they have a significant advantage in that they don,t tend to have issues with the lifter retention spider or dog bones failing
the aftermarket linked lifters tend to handle valve lifts exceeding about .500 and rpm levels exceeding about 5800 rpm much better and with fewer issues
why I was planning on using stock lifters is that I had them, being that the block is a factory roller 880 block I did not know retro-fit would work and you just showed me the drawbacks of the factory system.
from the first time I looked at the lifter spider when I opened up the 350 I thought it was weak, flimsy, and insubstantial. so is the spider the problem or are there other design problems with higher lift and rpm. could a billet spider be machined that would not bend like the cheap sheet metal spider, thinking of something with adjustable set screws for the hold downs.
why bother trying when the solution is simply use the time proven , well tested linked lifter design
money is the only problem, more overtime to pay for correct parts. just checked the rear cam bearings, of the two oil holes one was only half aligned with the oil groove the forward one has solid metal under it. checking even though I had decided I will pull and replace them anyway.
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