Generation V Internal Engine 2013-20xx LT1

12664572 huge cam error

Thread Tools
 
Search this Thread
 
Old Nov 21, 2023 | 06:57 PM
  #1  
Scarebird's Avatar
Thread Starter
Launching!
10 Year Member
Photogenic
Liked
Loved
 
Joined: Dec 2013
Posts: 255
Likes: 58
From: Portugal
Default 12664572 huge cam error

I bought a 12664572 from Michigan Motorsports under information on the web that it was 200/207°.

Nope, it was a 188/223° LT4 blower cam. When asked, this is the reply I got from MMS:


Good morning,

Back when you purchased that camshaft, everybody (including ourselves and several large GM parts retailers) who was selling that LT5 camshaft had it listed as being similar specs to the L86/LT1 camshaft, as that is what the information everybody had at the time showed the specs as being. I'm not sure if GM changed the camshaft now that the LT5 is just a crate engine rather than a production car engine, or if the information everybody had was wrong all along, but it was later discovered when one of the larger companies selling that camshaft measured it on one of their Andrews camshaft machines that the specs were quite a bit different than thought and we all updated our listings to show the 188/223 specs that they informed us of. At that time we went ahead and stopped selling that camshaft since it wouldn't be a good fit for most of our truck/SUV customers even though we hadn't heard any complaints from anybody about how it ran in those engines at all. We now sell the Texas Speed camshaft in the link below for the L86/LT1/LT4 DOD deletes. To use that camshaft on an L84, you would need to upgrade to LT1 style valve springs as well. If you don't want to run the LT5 camshaft, you can return it to the address below for a refund or store credit.

As you see Michigan Motorsports has stepped up on this even though it is not their error and will no doubt set them back some.

I will most likely get a L8T cam from them.
Reply
Old Nov 21, 2023 | 09:50 PM
  #2  
greaseball's Avatar
Teching In
 
Joined: Sep 2009
Posts: 16
Likes: 2
Default

Scarebird, I was mislead by the same bad information. The original information was incorrect on the LT5 cam when it first came out. The LT5 actually has different intake and exhaust durations, lifts, and LSA (and probably other differences, such as the fuel lobe). For instance, L86/L87/LT1: 200/207 duration at 0.050) with 116 LSA. LT5 cam: 189/223 duration with 120 LSA. Intake and exhaust lifts for the L86/L87 and LT1 engines .551/.524; the LT5 camshaft is .492 intake, .551 exhaust. These correct LT5 cam specs indicate that this cam is set up for a blower application (Gen V LT4 and LT5) and NOT set up for a normally aspirated application (GenV L86/L87 and LT1).

Unfortunately, like the OP, I followed the early information on the LT5 camshaft and swapped it into my L87 long block as part of a DOD delete. The engine is now complete but hasn’t been fired yet due to delays in my project. So now what do I do? Leave the cam in there and hope that there isn’t a noticeable penalty in engine performance? Or, pull the LT5 cam out now before the project is complete (front sheet metal is still off the car) and swap in a different cam? I’ve searched the internet and haven’t found any results from someone that used an LT5 camshaft in an L86/L87 or LT1 and reported the resulting dyno numbers after the swap.

I hate getting bad information from the internet!
Reply




All times are GMT -5. The time now is 09:55 AM.

story-0
Amazing '71 Camaro Restomod Is Modern Muscle Car Under the Skin

Slideshow: This heavily modified 1971 Camaro mixes classic muscle car styling with a fifth-generation Camaro interior and modern LS3 power.

By Verdad Gallardo | 2026-05-12 18:06:42


VIEW MORE
story-1
6 Common C5 Corvette Failures and What's Involved In Repairing Them

Slideshow: From wobbling harmonic balancers to failed EBCMs, these are the issues that define long-term C5 ownership and what repairs typically involve.

By Pouria Savadkouei | 2026-05-07 18:44:57


VIEW MORE
story-2
Retro Modern Bandit Pontiac Trans AM Comes With Burt Reynolds' Autograph

Slideshow: A modern Camaro transformed into a retro icon, this limited-run "Bandit" build blends nostalgia with brute force in a way few revivals manage.

By Verdad Gallardo | 2026-04-21 13:57:02


VIEW MORE
story-3
Top 10 Greatest Cadillac V Series Performance Models Ever, Ranked

Slideshow: Cadillac didn't just crash the high-performance luxury vehicle party, it showed up loud, supercharged, and occasionally a little unhinged...

By Pouria Savadkouei | 2026-04-16 10:05:15


VIEW MORE
story-4
Top 10 Most Powerful Chevy Trucks Ever Made!

Slideshow: Top ten most powerful Chevy trucks ever made

By | 2026-03-25 09:22:26


VIEW MORE
story-5
Hennessey's New Supercharged Silverado ZR2 Has 700 HP

Slideshow: Hennessey has turned the Silverado ZR2 into a 700-hp off-road monster with supercharged V8 power and a limited production run.

By Verdad Gallardo | 2026-03-24 18:57:52


VIEW MORE
story-6
Coachbuilt N2A Anteros Is an LS2-Powered C6 Corvette In Italian Clothes

Slideshow: A one-off sports car that looks like a vintage Italian exotic-but hides a C6 Corvette underneath-just sold for the price of a new mid-engine Corvette.

By Verdad Gallardo | 2026-03-23 18:53:41


VIEW MORE
story-7
Awesome K5 Blazer Restomod Comes With C7 Corvette Power

Slideshow: A heavily reworked 1972 K5 Blazer swaps its off-road roots for a low-slung street-focused build with modern V8 power.

By Verdad Gallardo | 2026-03-09 18:08:45


VIEW MORE
story-8
10 Camaros You Should Never Buy

Slideshow: There are thousands of used Camaros on the market but we think you should avoid these 10

By | 2026-02-17 17:09:30


VIEW MORE
story-9
10 LS Engine Myths That Refuse to Die

Slideshows: Which one of these myths do you believe?

By Verdad Gallardo | 2026-01-28 18:10:11


VIEW MORE