I have a 66 300 hp i would like to instal solid lifters. Is this a big deal should i change the cam as well or just drop in the lifters? The cam and lifters in place now are realativly new.
Solid lifters
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Re: Solid lifters
You can't do that. Camshafts for solid lifters are designed and ground differently than those for hydraulic lifters; they have to be matched as a set (cam and lifters).- Top
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Re: Solid lifters
Just curious why you would want to do this Bill? The 365 hp cars with solid lifters would also have been a higher compression ratio. Even if you went with a non-Corvette solid lifter cam, it is not likely to perform as well on the lower compression. It all seems to me like a lot of work and expense and you may end up with a very soggy engine.
Just my $.02- Top
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Re: Solid lifters
A lot of that noise is due to the loose clearanced forged pistons, and properly adjusted mechanical lifters should not be noisy.
Ever been to a classic car show. Most of the luxury cars from the prewar era had mechanical lifters and sometimes the only way to know they are running is to look at the fan and see if it is turning or not.
If you want to generate a little valvetrain noise, readjust the lifters to 0-1/8 turn preload, but it's still not going to sound like a Duntov cam and forged pistons.
Even with proper adjustment the Duntov cam is a little noisier than the 30-30 and LT-1 cams because the Duntov has very aggressive dynamics (jerk and acceleration) for the first few thousands of valve lift immediately above the tops of the clearance ramps.
Duke- Top
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Re: Solid lifters
One word of caution, something which I learned the hard way... Modern solid lifters pump more oil up into the head than did vintage lifters.. If you are going from a vintage set up to something new, you may need to visit your valve seals.
When I had my 1963/340 rebuilt we replaced the original cam with a new one but did not put in positive valve seals. The car smoked like a bandit.. Took me months to figure it out. Unfortunately the engine builder should have known better but did not... Once the problem was diagnosed properly, the fix was quick.. The car runs great today and the (little) more aggressive cam makes for a fun drive!
Good luck,
Joel- Top
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Re: Solid lifters
There is a viable alternative, which is, to use a modern solid flat tappet camshaft with milder timing than the Duntov/30-30/LT1 which all require at least 10.5:1 SCR to perform acceptably. Many modern design camshafts from the aftermarket, have a somewhat more aggressive lobe flank than the vintage cams as well as smaller clearance ramps (i.e. tighter lash settings). This will result in an engine that produces less mechanical noise and better torque and power. There is a downside to this, however, since nothing in life is free; the cam will be somewhat less durable than the vintage cam, on average, depending on its "ramp rate". Most, if not all of this loss of durability can be made up for with proper break in, camshaft hardening treatments, motor oil phosphorous content, and driving style.
A typical camshaft which will respond well with 10.0:1 SCR (your "low" compression L75) will have durations in the range of 220-230. One such camshaft that would work nicely for your application is Comp Cam's 12-222-4.
http://www.compcams.com/Cam_Specs/Ca...?csid=219&sb=2
Joe- Top
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Re: Solid lifters
DO NOT, repeat, DO NOT install a vintage solid lifter camshaft into your "low compression" engine, as has been suggested, unless you match the static C/R to the cam's timing specs. You will be disappointed.
There is a viable alternative, which is, to use a modern solid flat tappet camshaft with milder timing than the Duntov/30-30/LT1 which all require at least 10.5:1 SCR to perform acceptably. Many modern design camshafts from the aftermarket, have a somewhat more aggressive lobe flank than the vintage cams as well as smaller clearance ramps (i.e. tighter lash settings). This will result in an engine that produces less mechanical noise and better torque and power. There is a downside to this, however, since nothing in life is free; the cam will be somewhat less durable than the vintage cam, on average, depending on its "ramp rate". Most, if not all of this loss of durability can be made up for with proper break in, camshaft hardening treatments, motor oil phosphorous content, and driving style.
A typical camshaft which will respond well with 10.0:1 SCR (your "low" compression L75) will have durations in the range of 220-230. One such camshaft that would work nicely for your application is Comp Cam's 12-222-4.
http://www.compcams.com/Cam_Specs/Ca...?csid=219&sb=2
Joe
Joe-----
A 1966 300 hp engine has a factory rated compression ratio of 10.25:1. While actual compression might be a bit lower, it's also lower for L-76 or L-84 engines rated at 11:1. However, keep in mind that 1971-72 LT-1's had 9.0:1 factory rated compression and used the solid lifter LT-1 cam. They ran just fine.In Appreciation of John Hinckley- Top
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Re: Solid lifters
Joe-----
A 1966 300 hp engine has a factory rated compression ratio of 10.25:1. While actual compression might be a bit lower, it's also lower for L-76 or L-84 engines rated at 11:1. However, keep in mind that 1971-72 LT-1's had 9.0:1 factory rated compression and used the solid lifter LT-1 cam. They ran just fine.- Top
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Re: Solid lifters
Joe-----
A 1966 300 hp engine has a factory rated compression ratio of 10.25:1. While actual compression might be a bit lower, it's also lower for L-76 or L-84 engines rated at 11:1. However, keep in mind that 1971-72 LT-1's had 9.0:1 factory rated compression and used the solid lifter LT-1 cam. They ran just fine.
Joe,
"Fine" is a good way to put it, and I think that Mister McDormand would agree. But for 1971-72 the camshaft was no longer correctly matched to the engine's SCR. It was GM's cheap way out of the Clean Air Act's tightened emissions standards, and was probably inescapable due to the volume of cars produced. You know, Joe, that all engines' power ratings were dropped by "about" 10 per-cent across the board for 1971 as compared to 1970, and that was considering that both 1970-71 were still using the old gross horsepower ratings. 1972 saw an "on paper" loss in power/torque because of the new SAE net ratings mandated.
Since Bill is contemplating doing some mods to his engine, the response was designed to give him proper guidance in his cam choice as well as some insight as to the reasoning behind that choice.- Top
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Re: Solid lifters
Hi Bill if you go with solid lifters, They make them now with a hole on the bottom of the lifter, so now the cam gets pressure feed oiling! Iam put'em in the 63, wish I had them in all my cars. Phil 8063- Top
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Re: Solid lifters
Phillip, I would like to see a pic of that lifter. Sounds like a good idea but where on the bottom?
I wonder if another calibrated pressure leak would effect overall engine oil pressure? Just thinking out load.- Top
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