Ls/Vtec Engine Build – Dis-assembly of the B18a Block

Posted by in Automotive | September 18, 2011

Here’s the start to a new project I decided to undertake, my LS/VTEC Engine Build. I’ll be building a LSVTEC Motor from the ground up. Using all aftermarket parts. My goal is to swap this motor into a 88-91 Civic H/B Chasis (EF9) and build an ultimate track/auto cross car. Since the 4th generation civic is so light (around 1,100kg) it has great potential and a great horsepower to weight ratio for this motor.

What is a LS/VTEC?

If your not familiar with this setup, it’s when you use a B18A or B18B engine block from the Acura Integra (LS, GS, RS) and mate it with a cylinder head of a B-Series VTEC Head. In my case, I’ll be using the 1990 Acura Integra LS Engine (B18a1) Block, and a JDM B16a VTEC Head. The overall idea behind this hybrid swap is to increase the displacement and make much more torque over higher RPM’s. Your basically adding the high RPM VTEC head to a non-vtec block. This setup is also commonly called the Frankenstein Swap!

Acura Integra LS Guage ClusterThe donor car for the B18a1 block was a 1990 Acura Integra LS with just under 194,000kms, the car had the cleanest motor from about 6 different Integra’s at the auto salvage yard. I pulled the whole motor including transmission and cylinder head. Since the motor was fairly cheap, it was just easier to remove it as a whole. Working in a salvage yard with limited tools makes it a little more difficult. Lot’s of improvising has to take place! Especially when you come across the bolts that haven’t been wrenched on in 15 years and are seized in place…

B18a1 Engine on Hoist B18a1 on Engine StandOnce I got the motor home I removed the transmission, starter, alternator, A/C pump, exhaust manifold, and all the belts & hoses that were left on. Once all the excess fat was trimmed, the engine was mounted on the engine stand, ready for complete a dis-assembly!

B18a1 Engine Dis-AssemblyB18a1 Engine Cylinder BlockRemove the intake manifold and proceed to remove the main cylinder head bolts. To access the head bolts, first remove the intake & exhaust cam’s. Be sure to follow the proper head bolt loosening sequence as per Honda spec’s. To prevent warpage, unscrew the bolts in sequence from in-side-out in a criss-cross pattern 1/3 turn at a time; repeat until all bolts are loosed. Separate the cylinder head from the block with a flat blade screwdriver or pry-bar.

Set the original B18a cylinder head assembly as-side. We won’t be needing this one, I plan on trying to sell mine or at leased get the core charges back from the salvage yard.

B18a1 Engine Block, Oil Pan/Screen RemovedThat takes care of the top end, rotate the engine stand so you can work on the bottom end. Remove the oil pan, oil screen, and oil-pump assembly. Remove these items with care if you plan on reusing the gaskets (which I dont recommend). I’m using all new OEM Honda gaskets and seals, so I disposed of all the old ones.


Assuming you have already removed the flywheel (which you should of done when removing the transmission) then move on. If the flywheel is still on, get out the engine hoist and mount up to the engine. The flywheel can’t be removed with the engine on the stand, there just isn’t enough room.

B18a1 Engine Block Removing PistonsBare B18a1 Engine BlockTime to remove the crankshaft and pistons. Remove the right side cover and continue onto the main journal caps. Again, be sure to remove these using Honda’s loosening sequence. Remove both the main journal caps and the connecting rod caps.

Once complete, you can remove the piston/connecting arm assembly. Be careful no to scratch they cylinder walls when removing the pistons and connecting rods. I am going with both new aftermarket pistons and connecting arms. So these OEM parts can go into the scrap pile along with the B18a1 cylinder head and intake manifold.

B18a1 Crankshaft and main journal capsBare B18a1 Engine BlockOEM Honda B18a1 Crankshaft and main journal caps safely set aside. Now your basically left with a bare B18a1 engine block, ready for the machine shop.



Leave a Reply