Hi all, I just got my rst back from the bodyshop and eager to get started with the rebuild.
I'm about to put my new 1860 cc cvh engine in, but I'm not exactly sure if she will hold out. Its a 1600 cvh bored out 2mm resulting in a bore size of 1690 cc , in combo with a american tallblock crankshaft with a stroke of 88 this results in 1860 cc.
After looking up some info about overboring the cvh it came apparent that the cvh is of a 'thin wall design' in favour of weightsaving.
The engine-tuner which did the engine machining told me it would be fine.
(up to a certain limit of about 200 bhp at first)

Expected power for this engine is actually about 260 - 270.
Now, should I prepare for a big failure or is there a good chance I will get away with this?

 

A good friend of mine had a 1900cc phase 2 power engineering engine. The bores ended up cracking due to heat.

 

Personally i'd just run with it. It's done now, just prepared for a new engine.

Rick

 

They are a very good engine and every engine has its down sides. They pull very well,As rick says use it

 

i bet you couldnt run with tho, got to be around 100kg's

 

+2mm

 

+2mm overbore!

Without a sonic check of the individual cylinder wall thickness you are taking a big gamble.
Problem when an engine explodes - It takes out the expensive pistons, con rods, cylinder head and possibly crankshaft.
I wouldn't risk my investment in the other parts when the block fails.

 

A friend of mine also used a similar engine in his Cosworth W/M powered S1. ~1850 ccm and up to nearly 300 PS on full boost. Never had any issues with it. According to him and his experience with several standard and overbored CVH engines it gets critical from ~ 2.5 mm on. Although you'd have to have an eye on engine cooling, oil cooling and fueling.

 

Lol....

 

Not 100 % on this but did not the cvh come in 1600 and 1800 ? and I think the 1800 was a overbored 1600 anyhow so bore wise your within good limits

 

Nope. 1800 CVH had a longer stroke. 88 mm crankshaft as mentioned above. 1.6 just had 80 mm

 

Ah nice one good to know new things

 

you've had it built, i'm sure there is a warranty with it then?
use it, worst case is your engine builder will owe you an engine or refund IMO.

 

It's a cheapo CVH, hardly an investment. The pistons, rods etc will be useless in anything else as it is. TBH if the block cracks you'll notice a lack if power, oil/water consumption rather see the crank snap in half and exit through the geabox.

Rick

 

I've got a .5mm bored 1800cvh block, after doing a lot of digging about i found that the block is basically an under bored 1900 block and the walls a thicker as standard than a 1600 cvh so good for big power, mine was built by Ferriday enginerring and is an awesome motor.

 

the ferriday engines are spot on but limited by the rods and pistons but still good for 260

 

I hardly think a 260 to 270 HP cvh (Arjan expects) will come from a 25 pound cheapo engine build.
It always pays to know what you have (sonic check) before boosting the hell out of it, blowing it up, and then saying cvh's are sh*t.

Just my opinion.