SPM Engines

*Stewart Performance Machine is a professional, clean, friendly and affordable option for all your machining needs SPM Engines provides engine rebuilding and machining services for most foreign and domestic engine makes.

Based in Rockford Illinois, we are dedicated to providing the highest quility workmanship and precision on every engine. From dayly drivers to performance engines, we have a full catalog of parts for almost every application. Our machine shop provides services on cylinders heads, engine blocks, crankshafts and camshafts as well as blueprinting, dry lubricant and thermal coatings.

Operating as usual


To everyone that has been following SPM. I apologize for not updating in awhile. I've been very busy but will be back working on some builds and posting pics if you need a quote please message me.


Photos from SPM Engines's post


Milling and sizing this LS


Got all my valves cut, blued and lapped in on this 6 angle valve job for the Evo


Dry l**e on some valve stems..


6 angle valve job! 3 on the seat, 3 on the valve. This greatly decreases the distance the air must travel from the runner into the chamber as the valve cracks open resulting in great throttle response and power!


Checking thrust clearance.


Mains with ct-1 coated Tri metal pro series king bearings


Crank Polishing for the Evo


Port match, port and polish on the Evo..


Freeing up some horsepower with dry lubricants and thermal coatings. This is after the application process. Dry lubricant on the valve stems and spring. Thermal Coating on the piston tops. This is for an evo build we are putting together for a customer. We will be back with dyno numbers soon!


SPM Engines's cover photo


Here's a few pics of my most recent 383 build.. fully sleeved 4 bolt main hi nickel block.. I will top it off with a set of ProComp Aluminum heads after a radial angle valve job and a port matched air gap intake. it's also getting a roller cam, roller lifters and roller rockers from Comp Cams. I did this engine with a .062 copper head gasket from SCE to knock it down to 10.8-1 compression for pump gas. But with a quick gasket change it can be bumped to 12.7-1. This engine will be for sale! If you have any questions feel free to comment


SPM Engines's cover photo


Not done yet.. But you can see the difference between gasket matched and not!


Stewart Performance Machine is now a parts vendor! With a guaranteed lowest price! We carry.
Comp Cams
Crane Cams
Speed Pro
And these are just a few. If you are interested in making an order please call 779-772-2980 or message us on Facebook


Breaking in this bore bar machine..


SALE! All machine work 15% off! From stock repair to full out drag or track cars. Dry lubricants and thermal coatings available! Come see us or call at 779-772-2980


got me a new roller cart!


First start 500hp retro roller cam small block. just need a distributor and vacuum advance and she is ready to go!


bb 454 10.5-1 mild cam


SPM Engines


In the car! Finally! 76 vette


Small block project progress! Almost ready


For Sale! 96 Harley Heritage Classic $7500 obo


Roller lifters and rockers sb


New NBK heads 200cc 2.02/1.60


Sb bottom end ready for assembly!


New break in stand..! we do full blueprinted and documented, dyno proven and even break in custom builds for a turn key race car or street machine! Just call 779-772-2980 and ask for Tim..


Big block almost done.. 600 horse's! Just need to put her on the dyno for proof!


Timeline Photos


306 build for a drift car!


Timing a big block! Yes Sir!


302 that just came out of the steelabrater! Ready for her first bath now!


06 gsxr600 running rich and cutting out ended up being a bad power commander!

Videos (show all)

First start 500hp retro roller cam small block. just need a distributor and vacuum advance and she is ready to go!
bb 454 10.5-1 mild cam



Rockford, IL

Opening Hours

Monday 8am - 5pm
Tuesday 8am - 5pm
Wednesday 8am - 5pm
Thursday 8am - 5pm
Friday 8am - 5pm
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