[TimoFinn]

Are Summit Racing flat tappet hydraulic cams worth trying or are they just another china junk? What about their lifters? Are they any good, the pic in Summit`s pages shows that they are with hardened faces but i doubt it.

What about these GM lifters:
GM Performance 12371044 - GM Performance Hydraulic Flat Tappet Lifters - Overview - SummitRacing.com

and what is the difference to this lifter? It`s 23$ a piece so 16 times =368$
GM Performance 5232720 - GM Performance Hydraulic Flat Tappet Lifters - Overview - SummitRacing.com

[delawarebill]

i've use 2 of them with NO problems.. matter a fact i just put a new one in bout a month ago.. slight loop to it. the old one was smooooooooth idle... BORING..... thats why i changed.. after break in and oil change i did put in another bottle of break in additive for safe measure..

[AutoGear]

They're okay. Its someone else's design (obviously) and its probably a 20yr old design (or more) and its probably pretty close to spec. If the only thing you're ordering is a cam and lifters, if its for anything more than a street car, I'd contact Mike Jones @ Jones Cams in Denver, North Carolina. They do custom cams, turn around is 1-2 weeks and he has no problem shipping to you. Price is about twice as much for the cam, but the lifters he quoted me were cheaper than the expensive ones you asked about.

Now, I don't know if he has different prices for basic hydraulic cams or not; this was for a basic motor (307 SB Chevy). But he'll give you exactly what you need

[Mr. P-Body]

First, and most important, I know of ZERO camshafts made in China or anywhere else, for that matter, outside the USA, for American V8s and "performance". Where these rumors come from still amazes me.

Camshaft Machine Company is responsible for the majority of flat-tappet hydraulic cams ground today. Comp, Lunati, Crane, Crower, all use their facilities and supply "masters" for propietery grinds. They also produce the "generi-grinds" used by Edelbrock, Elgin, Summit, Wolverine, etc. Most of these are old-school cams with "proven" designs or old factory performance cams, which Melling was the vendor for "back in the day".

We (CVMS) use Comp almost exclusively. Hard to argue with the performance and success we've had with them. As for break-in problems, don't blame the cam maker. Pop had a saying: "When all else fails, follow instructions!" By that, I mean I've seen several wiped cam lobes. In virtually ALL cases, proper (recommended by cam grinders) break-in procedures were not followed completely. Modern oil MAY be a contributor, but I don't really think so. I say that because we break engines "in" all the time, using only 15W-40 Rotella or other such HD oil, and have had no lobe issues for many years.

For compression ratios under 9.5:1, we ALWAYS use a Comp XE or DE grind. Lunati "VooDoo" series is similar in parameters and performance. These modern "fast ramp" cams work VERY well in the lower compression, making them good choices for "pump gas" combos. Another company supplying these type grinds is Bullit Cams, but I have no "hands on" with their stuff. They claim to have the old UltraDyne grinds. If that's true, they're very good.

We also use Sealed Power lifters, pretty much exclusively, when using a flat-tappet hydraulic. Comp and Crower lifters have shown us problems oiling the "top" where the SP stuff has been worry-free. Comp assures me, if one uses a "quality" lifter (of which Sealed Power certainly is), they will honor their warranty. We don't use "anti-pump up" OR "fast bleed" hydraulics here.

FWIW

Jim

[AutoGear]

Harold Brookshire confirmed awhile ago that the owners of Bullet owned the majority if not all of his former UltraDyne designs. Harold is also responsible for the VooDoo line of cams as well. You can hardly go wrong with a UDHarold grind. He still advises people, though these days its mostly by phonecall.

[327NUT]

Mr. P-Body and AutoGear.....xlnt info!!!! I've also used 3 Summit cams/lifters for engines I built for friends who were "budget conscious". With the PROPER oil, additives if need be and breakin procedure I've never has a cam problem. It still just amazes how many threads come up with guys having problems with wiped out cams.

[TimoFinn]

Originally Posted by AutoGear

They're okay. Its someone else's design (obviously) and its probably a 20yr old design (or more) and its probably pretty close to spec. If the only thing you're ordering is a cam and lifters, if its for anything more than a street car, I'd contact Mike Jones @ Jones Cams in Denver, North Carolina. They do custom cams, turn around is 1-2 weeks and he has no problem shipping to you. Price is about twice as much for the cam, but the lifters he quoted me were cheaper than the expensive ones you asked about.

Now, I don't know if he has different prices for basic hydraulic cams or not; this was for a basic motor (307 SB Chevy). But he'll give you exactly what you need

hi Nate,

I knew that they are someone else`s cam`s just reboxed stuff and that sounds good if they are old tried and true cams.
I actually have been thinking of trying a L79 350hp cam for this (383) engine build, but i haven`t made up my mind yet. so many things to decide before buying anything.

[TimoFinn]

Thank`s for reply`s guys, i have many parts to get and i have not yet made my desicions yet but i am not in a hurry to do anything.

I have read and heard about cam failures and comp xe series are in a lot of those stories, but i have installed one comp xe in 355 and it has been fine.

Do you know about the GM lifters and the differences in them?

[AutoGear]

Timo

Hows my gearbox?

The L79 is a solid cam but it really needs compression to shine. I know enough to get myself in trouble with cams. If your spoken english is as good as your written english, I can PM you Harolds number. He's quite conversational and explains everything quite well in easy terms.

[Mr. P-Body]

In truth, Harold was responsible for the Comp XE products, too. He was an engineer for Comp when he came up with the "idea". In the late '70s, metalurgy and spring technology wasn't "up to the task" of the assymetric lobes and "fast" ramps. Comp shelved the project, so Harold took his patents and started UD (so the "story" goes, anyway). Once the patents ran "out", Comp dusted off their notes and went back after it. I've never met Harold, but have followed his work over the years. My understanding is he's now creating grinds for high-end racers through General Kinetics. Truly one of today's "super gurus".

There's no factory grind that can perform like the modern aftermarket grinds in similar parametric ranges. After using them for more than 10 years now, they too, are "tried and true".

Jim

[lt1silverhawk]

Hi Jim,


Not to change the subject or steal this thread, but while recently looking up some info regarding another thread on General Kinetics, I read that they had gone out of business a while back. Is that not true?

[AutoGear]

http://www.stevesnovasite.com/forums...p/t-86232.html

One post up from the bottom seems to be Harold's timeline as of 2008. Apparently hes had some diabetic health issues, and that phone number is not his active one anymore. I *think* one of the locals had a 'custom' cam spec'd by Harold and cut by Lunati.

[TimoFinn]

Originally Posted by AutoGear

Timo

Hows my gearbox?

The L79 is a solid cam but it really needs compression to shine. I know enough to get myself in trouble with cams. If your spoken english is as good as your written english, I can PM you Harolds number. He's quite conversational and explains everything quite well in easy terms.

Tranny is still in the crate my Camaro was in body shop in the winter and is waiting to be soda blasted and my friend will do a paint job to it so there is a lot of work to do and a lot of parts to buy.

You might confuse L79 to LT-1 cam, LT-1 was a solid lifter and L79 was hydraulic, here is one comparison of factory cams:

Chevy Small Block Hydraulic Testing - Super Chevy Magazine

[1971BB427]

Summit's cams are made by Crane. Check any cam specs that Summit lists and you'll find an identical cam listed in Crane's catalog. There are a few cams that Summit carries that Crane doen't catalog, but not many.
The lifters are all made by 2-3 companies that every cam maker in the USA sells with their cams, and none of them are made overseas. Summit lifters are identical to Crane, Comp Cams, and many others.

[TimoFinn]

Thanks a lot for you`r reply´s