Car:
Looking at a potential purchase of a 1995 Civic EX coupe that has a JDM B20B non-Vtec swap. I've owned two 6th gen EX's with stock D16Y8's and can work on those engines pretty well but, other than that I have not owned a Honda DOHC engine and never drove one until (above mentioned) yesterday. The seller seems very meticulous, straightforward and has agreed to let me do an upcoming compression, leakdown, block test and put it up on a rack to inspect for steering, suspension, leaks. The car seems to be in very good shape overall and just test driving it and doing a power balance test the motor seems very healthy so far. He said he purchased a shell from his friend and purchased a guaranteed JDM (stamped) B20B motor that has between 40k-60k miles He has put 7k miles on it since swap but purchased a work/DD vehicle and no longer drives the EX. He said the engine is stock non-Vtec, all new seals, with a (IIRC) '96 integra intake manifold that replaces the longer giraffe intake that is stock on these engine.

Manual transmission is out of Integra LS and has 100k miles on it, short shifter, weighted shift **** and shifts very well. New Exedy flywheel, clutch kit, bearings, rear main seal. A/C system is new with exception of the evaporator. Doesn't have power steering. New auto to manual motor mounts: was previously an automatic and converted to manual for swap. OBD1 ECU. Quality welded aluminum radiator with slim can reservoir. Cluster replaced with mint condition that reads 85k miles odometer. The car is titled as a "Duplicate" and mileage is "Exempt". The interior is an excellent condition, all electronics seem to work fine, no trunk leaks and drain channels have zero rust. Spare wheel well has zero rust or signs of leaks. Rota slipstream 15" wheels. Front and rear sway bars. Adjustable spring/shock (but, not coilovers).

I do not plan to mod or boost the engine in any way. Plan to get a good set of coilovers and new tires. For use as a daily driver and have a bit of fun when the opportunity presents itself. No street or track racing.
Handling is more important to me than horsepower. However, the torque gain is very noticeable compared to the D -series Vtec i am used to.

Concern:
Since test driving this car I've ben reading through info on B20's and it appears that these engines have a higher incidence of cracked piston walls compared to other B or D engines. I think the best explanation of why is listed on reply #6 in this post: B20 Cylinder Walls...? - Team Integra Forums - Team Integra As stated I plan to do leakdown, compression,and block testing on it to insure the health of the engine. Yesterday, I had him start it from cold start, did highway and city driving for 30 minutes, power balance (drop) test and there were no apparent misfires, cooling issues, no oil leaks or burning smell. No smoke of any color, or abnormal smell coming from exhaust on startup or at operating temp...just a few drops of water/condensation at startup emitting from tailpipe. No coolant mixed with oil or vice versa. From experience I know that head gasket leaks with Honda D engines generally the only sign of head gasket breach is loss of coolant from radiator and gain of coolant in reservoir.
As it stands now I don't suspect a cylinder crack with this engine but I'd like to get more input concerning B20's. This info is useful: https://honda-tech.com/forums/all-mo...nders-3088523/ and http://dwolsten.tripod.com/articles/jan96a.html

Questions:
1) Driving this engine stock and rarely red-lining it is there still a concern for piston crack?
2) What are signs/symptoms of piston crack
3) Any other known issues with these engines?

Any/all other comments or suggestions welcomed.

 

I found this reply in this thread: b20/vtec rev limiter | HondaSwap

" People keep thinking B20 blocks are so weak. In mild all motor conditions they can do the same thing an Lsvtec can do. They both have the same rod stroke ratio. The crank is the same every thing on a B18b is the same as a B20b except the sleeves and the pistons. The B20 pistons are 84mm when the B18b is 81mm. People think just cause the cylinder walls on B20s are a little thinner and they are symeese style sleeve they will crack which is usually true under high boost or retardly high compression and that's usually without being tuned. Don't get me wrong those sleeve are a little weaker but most I've seen that cracked a sleeve were running lean. Here in NYC alota people are b20vtec all motor with 12.5-1 compression, some are on the bottle with a 100shot, some are even running 10lbs on boost, and they are running good. You know why? because they safely tunned their ****. If you are worried just get ARP rod bolts because that is the weakest link in LS/B20vtecs."

 

bump
anyone please?

 

B20 engines are great, stock they are just as reliable as any other B-series, which is is say: very. I HIGHLY doubt you will have a cracked cylinder wall just from regular driving.

That being said, the symptoms of a cracked cylinder wall are the same as a blown head gasket: overheating, over-pressurized cooling system, coolant in oil, bubbles in radiator, etc. If it's not exhibiting any of these symptoms, you do not and will likely never have a cracked wall.

 

I should also add: in stock form, driven normally, these engines have no "achilles heel" that I am aware of, and will regularly last well past 200k miles.

 

You will be fine, b20 is a great motor. If you want to be safe run a wideband and get the car tuned but it's not necessary if it's a stock motor and stock ecu..

i have a 1999 crv with 363,000kms still runs great with just regular maintence

I also have a fully built b20vtec in my civic that is stock sleeve and bored .30 over (even thinner cylinder walls) and that car sees 9k often. I have had that motor for about 10,000kms now.

 

Thank you both for your replies. Makes me feel more assured. I tried to block test it yesterday but, we didn't have a good spot to let out coolant to get the level down low enough so that coolant wouldn't get into the block tester and mix with the test fluid. Will try again when I get it to a machanic in a couple days. The seller is very open to allowing test done on it, he's into Honda's and has done various builds including boosted. The test drive was a lot of fun and with proper coil overs and new tires it will be even better. The engine idled well, pulled well and growled unlike any Honda engine I've heard before (my experience is limited though). As long as everything test okay I plan to purchase it. He's also throwing in a bunch of spare parts including a machined B18c head from another engine.