12664572 huge cam error
11-21-2023, 06:57 PM
#1
Launching!
Thread Starter
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.
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.
11-21-2023, 09:50 PM
#2
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!
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!