Right now I am planning to go either a complete B18C5 engine swap or do an B20/Vtec using a Type R head. Anyways I checked up on crvtec.com and it says that the ideal rod to stroke ratio is 1.75. I want to make my B20/Vtec capable of redlining at around 8500rpm and with a good rod to stroke ratio it should be pretty reliable. My question is how can I get a rod to stroke ratio close to 1.75 using any neccessary parts that will fit into a B20 block. I am leaning more towards the B18C5 in terms or reliabilty and redline. I want my motor to be as reliable as any other Honda motor since it would be my daily driver and still be able to rev around 8000rpm and above. I know rpm's ruin people's motors but I am not talking about being reliable for like at least a couple years before I would have to rebuild. I am new to the B20/Vtec scene so I will probably be asking a lot of questions. But with your answers and help I hope to make one nice street car. Thanks in advance for your help and what are your thoughts and opinions?

 

Help anyone?

 

if your concerned about reliability than the b18c5 is for you. even though the crvtec can be somewhat reliable, it will be the same moneywise or more. you would have to resleeve the block and get better rods and pistons to get the revs. to make the r/s near perfect you would have to put the b16 crank in the b20 block, but that takes away torque. it will still be around 1750cc, but thats not why people do that hybrid, its for the torque(i think). if you want high revs like 9-10 get the b16. (dont forget the valvetrain if u do that.) the 8400 redline of the b18c5 will be good enough and u will be very happy. its not perfect but its got honda factory reliability.

b16's have a 1.74 r/s ratio.

 

r/s ratio is not everything!! b20/vtec built will rev to 9-10k if built right, who revs there engine that high every shift anyway. stock reliability=b18c5, the b20vtec is reliable but is not going to last 100k miles

 

As far as reliability of the B20 VTEC, it all depends on the quality of the parts you use, the measures taken in the buildup, and the competence of the builder. If you just slap a VTEC head on a B20 bottom end, don't be surprised if the engine does not last. In order to have a reliable B20 VTEC, there are a few things that need to be done:

1. Upgrade pistons and rods. Stronger and lighter units are needed to withstand higher RPMs. Also, the pistons need larger valve cutouts to accommodate 33mm VTEC intake valves (non-VTEC intake valves are 31mm).

2. Add oil squirters. These are present on VTEC engines but not non-VTEC engines. They help cool pistons and improve cylinder lubrication. These are important when it comes to improving engine longevity at high revs.

3. Upgrade to a GSR oil pump. Because you now have oil squirters, the VTEC mechanism, and better cam oiling, you need to be able to feed it. Upgrade your pump, as non-VTEC pumps are not up to the job.

As for rod ratio, consider that the B18C5 that you think is so great really does not have a great rod ratio. Like the GSR, it is only 1.58:1. A stock LS or B20 bottom end has a rod ratio that is 1.54:1. This can be improved to 1.58:1 by using a B18C crank. This destrokes the engine by about 50cc. But you will still have over 1900cc displacement - quite a bit more than a B18C5. A B17A crank will give you a 1.74:1 rod ratio. This would be very reliable and GREAT for turbo use. But it will lower displacement to only 1.8 liters. A B16A crank will give you an even better 1.85:1 rod ratio but will lower displacement to 1.7 liters. For allmotor use, I would stick with either the stock B20 crank or go with a B18C crank. If the engine is built competently with good quality internals and the required upgrades, there is no reason why it shouldn't be reliable. B16 and B17 cranks destroke the engine to the point that alot of the advantages of going B20 are negated. I would use oneof these combinations for forced induction only. Not that they couldn;t be used allmotor. There would just be little point.

 

dohcsideSi...can you tell me the right way to build the bottom end? I have no clue about B20/Vtec.

StorminMatt...thanks for the information it was well needed. I plan to get pistons and rods with my build up. I am thinking of either Endyn or Toda pistons but if anyone has another piston I should go with then please speak. As for rods I don't know which ones to get because I heard that you will have to get custom ones. Also have you heard of a company called Probe that makes pistons and rods? Crvtec.com recommend that set up but I don't know much info on them as far as price. Currently I am going to use a complete B18C5 top end but in the future I'll get some bigger cams with a valvetrain upgrade. As for the Oil pump should I get the GSR/Type R/ or an aftermarket company? Well I thats all I got think of for right now. Thanks for all the help I really needed it.

 

As for reliability I just want the car to make it at least 50k. I plan to purchase a new car in a couple years so I will sell this car to buy it. What tranny should be used with the B20/Vtec? Type R?

 

You can get by with Honda pistons, just get them from a different car. Here is a very good LSVtec page (same as CRVtec, just different displacement)- http://www.geocities.com/whiterabbit...r.html#Service

The rods in the LS are stouter than the GSR rods, so you should get by with those assuming you aren't entering an rpm contest. Shotpeening the rods is a good compromise. The oil jets and the GSR girdle are a good idea...not necessary from what I read though (someone said that some of the racecars disable their oil jets).

In the B series Hondas, the 1.54 R/S isn't the end of the world and gives a nice torque curve.

 

???

 

Can anyone help me determine which rods and pistons I need? I pretty much have everything else covered. Also as for the tranny does it matter which one I should go with? Is there a certain one better suited for B20/VTEC?