JGM Performance Engineering

Edward 3 months ago

Ryan at JGM Performance Engines did a killer job on my small‑block Ford. He built my 4.030" × 3.25" Boss‑block 331 with Dart Pro 1 heads, Super Victor intake, solid street roller, and a 750 double pumper. Pump gas setup, clean machine work, tight clearances — the thing runs exactly how a good 331 should. I’ll be honest: I basically dropped off a box of used parts and left it with him. He went through everything, figured out what was good, what wasn’t, and handled every last nut and bolt. No drama, no complaining, no “you need to buy all new stuff.” He just made it work. And the communication? Ryan always answers his phone. Every time. And he actually talks to you. He’ll go over parts, clearances, costs — whatever you need. He’s old‑school. Straight shooter. If you’ve got a detailed build, give him a spec sheet and he’ll follow it. He’s not an email guy; he’s busy machining, not sitting online all day. Honestly, that’s exactly the kind of person you want building your engine. He also did me a solid: he finished my engine in December and let me store it at his shop for a few months until I got past Christmas ($$$$) and was ready to dyno it. No pressure, no hassle. On the JGM dyno

Kalem Ginsberg 3 months ago

He does a lot of business and has great machinists. The head for my 3s GTE came out fantastic. The valve seats look amazing. Thank you guys. I'll bring you some real muscle, but I can find a good '68 firebird out there with the 400

jessica neiderhiser a year ago

After building cars for myself for years through my teens and young adult life with a friend that had a machine shop, when it came time to start a father daughter project and my friend had retired I was so happy to find Ryan! Ryan took the time to talk with me multiple times, and when we came to the shop he showed my daughter all that he was going to do and then did do! And what business owner these days answers the phone when you call and takes the time to answer questions and give you his knowledge?? Ryan, you are one of the most stand up people I have ever met and I am so glad that I found you and that you were a part of our ‘65 Mustang build. Eli

Doug Lindebaum 2 years ago

I have a 1969 Ford Ranchero with a 250 cu. in. I-6. It is a car that has been in the family since my grandfather bought it new. My dad drove it for a few years after my grandfather couldn’t any more and then I acquired it. Around 134K the engine started getting tired consuming a bit of oil and hard to start due to fouled plugs and low compression in a couple of cylinders. I also couldn’t keep radiators in it because the head gasket was probably leaking. There is no reputable machine shop/engine builder in Ventura to do the engine block and head together that I could find. I ran in to a friend of my dad’s and asked him who he used and he referred me to Ryan over at JGM Performance in Valencia. I called Ryan and we talked about my engine and the rebuild. He was very honest and up front about every aspect of the process. I had to wait a couple of months until he could schedule my engine in. Ryan called me out there a couple of times during the build to view the progress and see their opperation. Ryan and his employees do very professional and detailed work. I got the completed engine back after a couple of months. It turned out beautiful, like a piece of art. I got the engine and tr

Robert Klein 3 years ago

My wife’s 2006 Tacoma 4.0L V6 needed a head gasket replaced at 275k miles. I decided to tackle the job myself and quickly realized the easiest way to do this was to remove the motor. After removing the motor and both heads, I realized the way to do the job right was to have the heads rebuilt and sealing surfaces refinished. By the way, resurfacing the sealing surface is a must if you are using the factory multi-layer steel gaskets. Asking around work, JGM Performance Engineering or “Jim Grubbs Motorsports” for the old schoolers, kept coming up as the place to go. I spoke with Ryan, the owner of JGM, and immediately I knew this was the right place to go. Ryan is extremely knowledgeable about all aspects of engine rebuilding and will answer all of your questions honestly. As an engineer, I tend to do my research and have learned the devil is in the details with this type of work. And JGM pays attention to those details and will get it right the first time. Even though they specialize in American engines, Ryan’s assistant Machinist used to work extensively on Toyotas and did a great job on the heads. I couldn’t be happier with the outcome. Both heads were rebuilt beautifully, sealing