GSK
Legacy Member
1. The Down Side.
The B18a/b has a low r/s ratio 1.53 which is not bad compared to the 1.58 of a gsr. The b18a/b was not made to rev over 7000 r.p.m's so it has poor lubrication, bad rod bolts, rods, oil and water pumps, and piston valve relief’s. You can fix all these problems, as you can install vtec block oil squirters for lubricating the rods and piston. This helps to save the pistons, rods and bearings at high rpm's. You can install ARP rod bolts. And get upgraded rods or shot-peined. Also some vtec pistons are recommended.
2. Oil lines.
The Ls block does not have a Vtec oil passage (you need this hole to produce the oil pressure to lock the vtec lobes rocker arm) so you will need to tap the hole on the head or weld it shut. When threading it shut use a 1/8ntp fitting. Its best to have a machine shop thread it for the 1/8th fitting and then just screw it in. Next you have to make an external line from the oil pressure sender to the head. Use a 4an to 3/8th ntp plug on the head to a steal braided line to tee'd of to the oil pressure sender hole. You will need a 1/8th tee fitting, a 1/8th to 3/4th's fitting for the line to the tee, a 1/8th to 1/8th adapter to plug the block, and plug the oil pressure sender in the back of the tee. So it will look like this (the T will be used as the tee fitting) 18th to 1/8th adapter T oil pressure sender sensor oil line to head. A suggestion is to have the tee fitting so it is not directly on the block (especially if you are installing an oil pressure gauge) as it can literally crack the threads and you will shoot oil everywhere. So try to run ss lines to someplace that can support the weight.
3. Head gasket
You will use the Ls head gasket.
4. Dowel pins:
The head needs to be modified for the dowel pins to fit. You have to move and re-drill the dowel pins to be able to fit the head. On the intake side right below where you put the 1/8pipe fitting that plugs the vtec oil passage, you will drill and install one of the dowel pins and do the same on the other side at the exact same point.
5. Timing belt
You will use the Ls timing belt if you use the Ls water pump and the gsr if you use a vtec B17/16 or B18c1/5.
6. Head studs
You will use the vtec head studs for the ls/vtec set-up. I suggest ARP if you want to spend the money.
7. Oil Pump.
The oil pumps on the ls's is so bad so you might want to upgrade to a vtec one or a b20 as they are same part number as the gsr.
8. Heads.
There are many heads you can use and there are little differences between them.
First off there is the GSR head which give you a higher compression than the other b-series heads because of its 41.6cc combustion chamber. The smaller combustion chamber makes .2 more compression. Then there is the b16/17a head which are the same the only difference is that the b17a has a p61 stamped on the back of the intake manifold the b16/17a head is a better flowing head 5.25% in fact and a larger combustion chamber 42.7cc's. Then there is the type r which flows even better than the b16a head and has the same combustion chamber. To put this in perspective the b18a/b has a 45cc combustion chamber.
9. GSR Block Girdle.
You can use the GSR block girdle on the ls. This will reinforce the bottom end and keep the moving parts in its place. All you need to get is the 3 main caps in the middle, bolts, windage, oil pan and oil pick.
10. Pistons.
You can use any b-series vtec piston in your ls block. Any 1.6 b-series piston will be raised by about one full point in the ls block like the b16a(pr3 pistons will raise it from the stock 10.2 comp in the b16a to 11.2ish in the ls block so keep this in mind when building the ls block. Also keep in mind about the combustion chamber size (See heads) when building the motor. . With a GSR, add .2 comp to the stock ratio. (Warning: these are all estimates: they could be off a little). If you want you can spend money in high quality aftermarket pistons.
B16a head and pr3 pistons 11.2
B16a head and p30 pistons 11.4
B16a head and p72 (ao) pistons 9.9
B16a head and p72 (00) pistons 10.5
B16a head and p73 (ao) pistons 10.7
B16a head and p73 (00) pistons 11.2
B16a head and p61 pistons 10.4
B16a head and pct (CTR) pistons 12.2-3ish
B16a head and pr4 pistons 9.5
Add .2 to all to calculate the GSR head with all of these.
Type r and b17a heads have the same combustion chamber so calculates the same
ADVANTAGES
· Low-end torque characteristic OF B18A or B18B.
· High-end horsepower from VTEC head
WHY?
1. B18A or B bottom-end has longer stroke thus capable of generating better torque response than Vtec bottom-ends.
2. B18A or B top-end has port and cam limitations to produce high-end horsepower, although B18 B is slightly better.
3. Unavailability of billet aftermarket cams for B18A or B.
4. All aftermarket cams for B18A or B are reground cams and are notorious for accelerated wear on top-end components.
5. Cars with aftermarket high lift cams usually have rough idle which affects drivability.
6. Price for head porting and cams is much higher than the LS-Vtec conversion.
7. With LS-Vtec conversion smooth idle is maintained while flat torque and high-end horsepower is maximized.
8. Availability of factory performance parts for Vtec top-end is more readily available:
9. Type-R cams, manifolds, and other components.
Disadvantage :
1. Require complete engine overhaul for installation
2. Rev limitation similar to B18A or B
PS.: This is the complete english version, the French version coming soon... I reedit this post for hater who like complicate things and don't make constructive opinion or help me for things i didn't say or known as.
Thanks. *tu*
The B18a/b has a low r/s ratio 1.53 which is not bad compared to the 1.58 of a gsr. The b18a/b was not made to rev over 7000 r.p.m's so it has poor lubrication, bad rod bolts, rods, oil and water pumps, and piston valve relief’s. You can fix all these problems, as you can install vtec block oil squirters for lubricating the rods and piston. This helps to save the pistons, rods and bearings at high rpm's. You can install ARP rod bolts. And get upgraded rods or shot-peined. Also some vtec pistons are recommended.
2. Oil lines.
The Ls block does not have a Vtec oil passage (you need this hole to produce the oil pressure to lock the vtec lobes rocker arm) so you will need to tap the hole on the head or weld it shut. When threading it shut use a 1/8ntp fitting. Its best to have a machine shop thread it for the 1/8th fitting and then just screw it in. Next you have to make an external line from the oil pressure sender to the head. Use a 4an to 3/8th ntp plug on the head to a steal braided line to tee'd of to the oil pressure sender hole. You will need a 1/8th tee fitting, a 1/8th to 3/4th's fitting for the line to the tee, a 1/8th to 1/8th adapter to plug the block, and plug the oil pressure sender in the back of the tee. So it will look like this (the T will be used as the tee fitting) 18th to 1/8th adapter T oil pressure sender sensor oil line to head. A suggestion is to have the tee fitting so it is not directly on the block (especially if you are installing an oil pressure gauge) as it can literally crack the threads and you will shoot oil everywhere. So try to run ss lines to someplace that can support the weight.
3. Head gasket
You will use the Ls head gasket.
4. Dowel pins:
The head needs to be modified for the dowel pins to fit. You have to move and re-drill the dowel pins to be able to fit the head. On the intake side right below where you put the 1/8pipe fitting that plugs the vtec oil passage, you will drill and install one of the dowel pins and do the same on the other side at the exact same point.
5. Timing belt
You will use the Ls timing belt if you use the Ls water pump and the gsr if you use a vtec B17/16 or B18c1/5.
6. Head studs
You will use the vtec head studs for the ls/vtec set-up. I suggest ARP if you want to spend the money.
7. Oil Pump.
The oil pumps on the ls's is so bad so you might want to upgrade to a vtec one or a b20 as they are same part number as the gsr.
8. Heads.
There are many heads you can use and there are little differences between them.
First off there is the GSR head which give you a higher compression than the other b-series heads because of its 41.6cc combustion chamber. The smaller combustion chamber makes .2 more compression. Then there is the b16/17a head which are the same the only difference is that the b17a has a p61 stamped on the back of the intake manifold the b16/17a head is a better flowing head 5.25% in fact and a larger combustion chamber 42.7cc's. Then there is the type r which flows even better than the b16a head and has the same combustion chamber. To put this in perspective the b18a/b has a 45cc combustion chamber.
9. GSR Block Girdle.
You can use the GSR block girdle on the ls. This will reinforce the bottom end and keep the moving parts in its place. All you need to get is the 3 main caps in the middle, bolts, windage, oil pan and oil pick.
10. Pistons.
You can use any b-series vtec piston in your ls block. Any 1.6 b-series piston will be raised by about one full point in the ls block like the b16a(pr3 pistons will raise it from the stock 10.2 comp in the b16a to 11.2ish in the ls block so keep this in mind when building the ls block. Also keep in mind about the combustion chamber size (See heads) when building the motor. . With a GSR, add .2 comp to the stock ratio. (Warning: these are all estimates: they could be off a little). If you want you can spend money in high quality aftermarket pistons.
B16a head and pr3 pistons 11.2
B16a head and p30 pistons 11.4
B16a head and p72 (ao) pistons 9.9
B16a head and p72 (00) pistons 10.5
B16a head and p73 (ao) pistons 10.7
B16a head and p73 (00) pistons 11.2
B16a head and p61 pistons 10.4
B16a head and pct (CTR) pistons 12.2-3ish
B16a head and pr4 pistons 9.5
Add .2 to all to calculate the GSR head with all of these.
Type r and b17a heads have the same combustion chamber so calculates the same
ADVANTAGES
· Low-end torque characteristic OF B18A or B18B.
· High-end horsepower from VTEC head
WHY?
1. B18A or B bottom-end has longer stroke thus capable of generating better torque response than Vtec bottom-ends.
2. B18A or B top-end has port and cam limitations to produce high-end horsepower, although B18 B is slightly better.
3. Unavailability of billet aftermarket cams for B18A or B.
4. All aftermarket cams for B18A or B are reground cams and are notorious for accelerated wear on top-end components.
5. Cars with aftermarket high lift cams usually have rough idle which affects drivability.
6. Price for head porting and cams is much higher than the LS-Vtec conversion.
7. With LS-Vtec conversion smooth idle is maintained while flat torque and high-end horsepower is maximized.
8. Availability of factory performance parts for Vtec top-end is more readily available:
9. Type-R cams, manifolds, and other components.
Disadvantage :
1. Require complete engine overhaul for installation
2. Rev limitation similar to B18A or B
PS.: This is the complete english version, the French version coming soon... I reedit this post for hater who like complicate things and don't make constructive opinion or help me for things i didn't say or known as.
Thanks. *tu*
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