Refreshing Your Spec E30 Engine

Refreshing Your Spec E30 Engine

Whether you’ve got an issue with your BMW motor or you only wish to refresh the one in your Spec E30, acquiring a tight, dependable power plant is vital for a pleasant and cost-effective racing year. For Pro 3 Racers in Washington State here are some tips for rebuilding your Spec E30 engine. If there are any hobbyists out there that find this a bit more complicated than originally anticipated you can check out this website ( about BMW E30 maintenance and repair options in the Redmond area of Washington State. They seem to be the go-to guys on the East Side and in the Pro 3 circuit for BMW repair.

Finding A Machinist

Why are parts so pricey? Quality machined parts are well worth the cost. Machinists have already have invested big bucks on all of the resources needed to correctly rework the interior mechanics of the motor and the parts needed to properly run it. To get a better understanding of what i am talking about, take apart your engine block and look at the detailed machine work done be BMW. The parts are well thought out designs that should be recreated carefully when rebuilding the engine. At first glance, you will see what I am talking about, for those of you out there not so familiar with the inner workings of an engine you are going to have to take my word on this one. When I’m rebuilding an engine with the intention to race, I want to make sure the parts are well manufactured and will last as long as possible.

A machine shop can also let you know which things you’ll have to replace and the things you’ll have the ability to reuse. In my experience, the machine shop usually can do a once over and identify anything that is salvageable and anything that definitely needs to be replaced. Having someone with a trained eye identify those things for me has saved me tons of time and money.

Get A Repair Manual

The internet is full of great information, but nothing beats having a manufacturers repair manual handy in the garage while you are rebuilding. Repair manuals are full of invaluable information you will need to reference if you want to rebuild the engine correctly. This is really where I sourced all my specs for rebuilding the base end, from torque to ring gap configurations. All you’ll have to do is follow the manual, there is no guesswork. And if you find yourself struggling you can always use Google to search for the information you are in need of.

Gathering And Preparing Your Parts

Once you have the proper manual, the new parts have been machined properly, and you have any rebuilt parts finished and ready for assembly it’s time to get everything into the garage where you will be assembling the engine. When the block and components are all gathered, you can start the assembly process, which for me, started with a coating of flat black paint to the engine block. You are going to want to paint the block to protect it from rusting after it’s been washed and cleaned. Keeping the block rust free will help extend the life expectancy of the engine. On top of that, a flat black engine block looks pretty sick sitting inside your car! I like to use flat paint over gloss to better identify any leaks that may occur. Fluids tend to stand out better on flat paint rather than gloss.

Next, I sized the rings into the cylinders one at a time before every ring was gapped perfectly. You gotta take your time doing this, once the rings are filed you are stuck with what you have, so take your time and do it right. You are going to repeat this process for every ring in each canister. It takes a bit to get into a groove, but once you nail the first few it gets easier. Again, take your time! After you are done, assemble the pistons and rod loops on the connecting rods. Prior to cleaning the pistons, I labeled them to make sure that when it was time to reassemble they went back into the original bores I took them out of.

Next, I begin installing the crankshaft. When the main bearings are set up in the block, set the crankshaft aside and examine the clearances for every bearing. Then apply some assembly lube on the bearings before installation.

Next, put in the front and rear main seals. I installed my seals in their housings once I cleaned them up. Use just a small bit of motor oil on the seals so that they slide across the crankshaft readily as you operate the housings on the dowels. Once that has been done and everything is in place you can begin to tighten them down.

You can flip the block now and drop the pistons in. I use a light coat of motor oil on the cylinders and pistons to get things in easier. I would suggest getting a piston ring compressor and carefully tap all the pistons into their bores. If there is resistance, do not force it since you’ll break a piston ring. Pull it out and start over. Also, make sure you align every piston so the arrow points down into the front of the block.

When the piston pushes beyond the ring blower, ensure that the pole is properly aligned to the crankshaft. During preparation, you will have had to set up the brand new rod bearings on the rods and rod caps in addition to purchasing new rod bolts for the engine. Install the pole cap and bolts finger tight for now till they’re all in. Again, verify that the bearing clearance is accurate. Once this has been done with all six-rod bearings, remove the pole caps and use assembly lube on the bearings and then twist the bolts tight enough for installation.

You must make certain that the crankshaft rotates 360 degrees before proceeding. Next, we need to set up the windage tray, then you are going to want to temporarily bolt it into the block with a couple bolts until you are ready for a more permanent installation. Turn the crankshaft by hand to find out if there is any disruption between the crankshaft and the windage tray. During this installation, I needed to gently adjust the windage tray to get the crankshaft to rotate properly.

When the windage tray is about ready to install, you can set up the oil pump and pressure-relief valve. Don’t forget to put in the oil pump shaft which connects the intermediate shaft to the oil pump or else you’ll not have the proper oil pressure needed on startup and you’ll destroy your motor. Twist the intermediate shaft by hand and check to make sure that the oil pump operates freely. I also previously set up the oil pan by bolting it into the oil pan area. It takes a little work to get right initially, but in the end, it was worth getting it done right.

The remaining part gets bolted back exactly how they were removed. If you have forgotten how you did it, simply refer to the manual or jump online and check out Youtube for a visual reference. I also replaced my water pump and timing belt while I was in there, it’s cheap enough to justify doing while you are under the hood. I think all of these components should be replaced while you are in there, especially before hitting the road.

Good luck with your E30 engine rebuilds, I hope this helps.

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