Isn't that a vote for GM crate motors? Who built it is someone who does only that for a living, has done thousands and uses brand new GM parts to exact spec, backed by warrantee.

The non GM crate guy would be the worry it seems. Who knows who built it and with which parts.

 

ZZ383 .... drop in and go .... As said above...GM knows how to build motors.. and stands behind them ...

 

That would be a good theory if there weren't bad engines coming out of the factory too. Last month a friend of mine bought a new ford pick up. He found a vibration at a particular speed. He took it back, they ballanced the tires. Still vibrated. He took it back, same thing again.
He brought it out and we found that it wasn't speed related, it was rpm related. As the engine reached at particular rpm the engine would shutter, while in park. So much so that with the doors open you could see the doors vibrate when a particular rpm was reached.
So, he took it back and showd them. They keep it a week and call him to get it. On the way home he learns that he or his truck still has this issue. SO he takes the complaint to Corporate to resolve.
He got a letter that the findings were that the condition his truck has is normal in new trucks. I suspect either a torque converter or an engine unbalance problem.
So, all that comes from the mothership isn't always correct, and as it seems at this point, getting it corrected isn't any easier.
Unless under warranty the engine fails, the issue won't be corrected by the company.
True you would know what parts the GM would be using, but you also would know if you had an engine built and ask for certain componants be used.
In an assembly line you do have someone who only works on certain engines all day. He puts part A into location B and moves on. I really don't think they take the time to check gaps or clearances at every location, or they would be more expensive. It seems to me that many assume that the person on this assembly line is a highly trained technician and not just another assembler. Jasper builds engines all day long and I don't read everybody dropping in their engines.
The most difficult part of the problem is finding a builder who IS good, as there are many out there who are not. The length of time one spends at a particular task doesn't necessarily mean they are accomplished at that task.

 

I've heard some pretty terrible stories about GM crate motors. Someone has a video of a ZZ454 on the dyno shooting a connecting rod out the side of the engine block at only 5300 RPM, the recommended engine redline is 5500 RPM from GM themselves

 

Just due to the sheer number of crate motors GM sells, it's not shocking there are horror stories out there.

 

HI again,

The reason I started this thread was to find real world info about what is available. The one crate manufacturer with the 5 year 50,000 mile warranty has the best so far. I'll give them a call and ask a few questions.
The only engine builders I have heard of here in the Spokane/North Idaho area don't get high reccmendations in the reliability/warranty service departments until you get into the $5000 range.

Ray

 

Most reputable crate engines have pretty decent odds. I've had 99% good experience with the GMPP stuff, but I always drop the pan regardless. Back a number of years, the GM Targetmaster stuff was sheer garbage, but I haven't seen a bad GM Parts or GM Performance engine failure in a long time.


A shop-built engine will always be far better aligned with the application - but as noted, although the quality from a good shop may be higher...the challenges of finding a really good shop are always a very real issue.

 

I've run 91 octane non-eth all summer with no problems. I did fill it once with 89 w/ethanol and it seemed to run ok on that tank. Just not something I think I want to make a habit of.
The ethanol/non-ethanol I think is more of an issue with gumming the carb up when they sit over the winter and doesn't appear to effect performance much that I've noticed.

 

If you are talking about West Coast Engines, talk to Brady, he's the owner and he called me to go over all my specs when I wanted to order. I was very impressed with their customer service!

 

Don't confuse octane rating with ethanol content. Apples and oranges.

 

Another question for Hop's 75.
I was talking about West Coast. Wil talk to Brady. Do you know what brand of heads on your engine? I noticed on their 350 that they sometimes use RPC brand. I have seen some questionable reports about these. They offer them as a no cost u[grade on the 350. The 383 375 doesn't say anything about the heads.

I'm afraid the GMP zz383 sounds good but broke the bank. The GMP Vortec 330 is about as far as I could go. If anyone has dyno results for that one I would be interested in knowing results.

Thanks Ray

 

I just went with there basic iron heads. Nothing fancy but they work and no additional cost like there is if you go aluminum!

 

You have to go with odds here. Trust GM or trust some guy trying to make a living building engines. Frankly, with my experiences with supposed "experts", I will go with GM. Every engine guy I talked to says he builds the best engines and proceeds to bash his competition. I thought Scat was a good crank, only to find out it was machined improperly, I thought I could trust Summit to provide me with a case that was properly rebuilt,...wrong again. The local rebuilder I talked to went on and on about how my mistake was buying Scat, and that I should have bought an Eagle. But there are as many who say Eagle is junk. Or better yet, tell me to buy a Callie or Crower at three times the cost like its no big deal. It never ends with this stuff, and nowhere moreso than on this forum, as well as many other forums filled with experts. Any given forum you will find opinions 180 degrees opposite each other. AFR versus Profiler, roller versus flat tappet, GMPP engines versus Blueprint, ATK, and the biggest joke is the constant message to find a local builder.

As far as I am concerned, the only guys who have creditability are guys who have spent the last 30 year building motors, and I am not one of them. And since I don't know any of these guys personally, I am screwed. My only choice is to go with the odds and trust GM. I cannot afford to get burned while crossing my fingers that some expert is really an expert.

It would have been alot easier if I could have found a consistent story about what is good and bad, but you can't. If there are ten guys talking about the best way to get a good reasonably performing reasonably priced 350 engine for my Corvette, there are ten totally different opinions on how to do that. And that is useless for an inexperienced person such as myself.

 

And one more thing since I am on a roll. Why is it always necessary in every thread to have some ridiculous and extreme comment about running 11:1 compression, or talking about HP at 7000 RPM. If this was a NASCAR engine building site I would get it, but this is about C3 Corvettes that I am quite sure are predominantly average every day classic street cars, with guys looking just to have a little more juice than stock. It serves not purpose to muddy up a thread that some are trying to get useful information from.

 

Most, but certainly not all, of the folks here would be happy with a reliable, affordable engine that makes around 1 - 1.2 HP/CID.

 

Externally balanced.

 

My buddy blew up his 81 c3 with a 4 speed and 3.73 rear end. He bought the gm crate 260 and took the stock cam out and put in the good old Comp 268 HE cam with 218-218 Dur. at. 050. .454 lifts, 110 lsa. The 290 Hp crate has the old l82 cam which is a little soft on the low end but wth your 4speed and 3.55 rear may be okay. The 218 cam in his crate 260 has tons of low and mid range but of course the gm warranty would be void with the cam change. Seems like most of the warranties are a crap shoot anyway. I had a 76 l82 and I swapped the l82 cam for an Isky 264 Mega cam with 214-214 @ .050, .450 lift on a 108 lsa and had much better low and mid range than the l82 with my 3.36 rear and T400. With your high mileage l48 maybe the stock 260 crate would be enough power for you. I think your 750 edelbrock carb is a bit much for a stock l48 and you may be losing some drivability with an overly rich mixture. I have a 600 cfm 1405 carb on my carbed 84 c4 with dart heads and a healthy cam but had to lean out the carb some after installing a autometer afr gauge which showed the rich fuel mixture. Runs a lot better now.

 

My car does run rich. Looking at previous owner records he wasn't happy with the perforrmance, A dyno shop ended up putting on the bigger carb as he wasn't getting good flow to several cylinders. They also put on a manifold with numbers relating to a Camaro, not a Vette. Probably due to the infamous Vette low rise manifold of days past. As I stated before the car is comparable to a BMW Z4 2.5 which has 10 less rated hp and weighs a couple hundred pounds less. It is what it is, a typical L48. I would like to improve on that

I had considered camming up a GMP 290hp, but if I am going to void the warranty, I might as well find a good rebuilt engine with more power to start with and a warranty. Starting this thread was my way of trying to determine a good builder from people with crate engine experience. Thanks for the info on the 260 hp engine, but I would start above that.
Ray

 

Take a look at tri star engines in Baldwin wisc. They have many crate engines and are a big company with very good reviews. Just google it.

 

These statements all lead me back to my comment above regarding a good dyno tune - from your statements, there's a lot of performance to be gained for you in a good tune. If it has a too-big carb that isn't even set up right...then it's not performing to it's potential by a long shot.