Compression/ Bottom End Work..?

[evans1089]

Hi all, when i had the vtr mapped up about a month ago i was told i had a compression problem on the bottom end, perhaps its the piston rings getting old?

What are the true facts that are my disadvantages of this? As i want as much as, out of vtr as possible after spending £700 on the cams and remap.

What can i do? What can i change or add?

Much appreciated ! :y:

[swampy]

Low compression can be many things
worn rings
worn cylinder bore
worn valve seats
valves not closeing fully

do a compression test and try and work out where the problem is.

[evans1089]

Cheers mate, what bottom ends can be put underneath a vtr head? and what are the benefits?

[swampy]

Havent got a clue
but you can normaly mix and match bits to alter compression and cylinder capacity
things like different crank and pistons will alter things alot
have the crank, rods and pistons dynamicaly balancd
this will help it rev smoother and sometimes allow a higher rev limit.
Couple it with a lightend balancd flywheel and crank pulley and you will get a very fast hard revving engine.
The lighter the items attachd to the crank the better!

[evans1089]

Havent got a clue
but you can normaly mix and match bits to alter compression and cylinder capacity
things like different crank and pistons will alter things alot
have the crank, rods and pistons dynamicaly balancd
this will help it rev smoother and sometimes allow a higher rev limit.
Couple it with a lightend balancd flywheel and crank pulley and you will get a very fast hard revving engine.
The lighter the items attachd to the crank the better!

Great info mate thanks, i'll get onto it now :D

[ldavies]

different topic but whats the saxo like since you had it re mapped.

[evans1089]

different topic but whats the saxo like since you had it re mapped.
pulls alot stronger and quicker from 4000+

[Liam_]

I don't think you have problems with compression - get it compression tested if you're unsure.

You're running a raised rev limit with the PH3 right? You know you need uprated valve springs and caps to do that? Otherwise it will suffer from valve float and lower performance.

[williamsvts]

a leak-down test would be better imo when trying to fault find.

[spiderxjz82]

You're running a raised rev limit with the PH3 right? You know you need uprated valve springs and caps to do that? Otherwise it will suffer from valve float and lower performance.

He speaks the truth! I had to alter the head quite a bit with my PH3 cams.