NVO 83 cam... anyone any experience of it?

[S_Gault]

Im normally a user of the AST19 in my Sprint engines but a customer recently brought me this NVO 83.

I was wondering if anyone has used on in a 1600 (typical group A spec)

Steven

[Stuart]

i doubt many on here would ahve used it but how about this for a revalation "suck it and see"

if you stick to only using/doing what youve done for the past X years and never deviated from it then you will never find out what else is about. Its called research, you get to push new boundaries etc and discover that what you had been doing while right might, not have been the best with new gear.

ok it will cost a bit of money if its a pap setup, but what if its as good if not better than your usual setup?! hmm

If ive not tried something in this way before ill just jump in and give it a whirl if the price is right lol eg solid profile flat nosed cams, ive never considered them but thought ahhhh sod it whats the worst that can happen?! so we will find out within a month (with a bit of luck). Then again ive not got a benchmark to compare against lol.

just a suggestion

[S_Gault]

christ who bite your head off.

heres my point-

The AST 19s are winning this year (by a country mile), just set 2 class records last week with 2 different drivers, so if someone has used it then great but have you ever heard if it aint broke dont fix it.

Oh and i do stacks of development (thats why i have a flowbench and use a dyno) and as for your flat nose cam...pretty old hat.

i was asking a simple question,

[Aragorn]

is there any way of measuring the two cams?

i mean i know they provide specs but they may well use different refrence points etc

if u measure the overlap, duration and lift of both and compare u might get an idea of how its gonna perform

a quick uneducated look at the specs from kent show some differences in the timing, duration and lift factors so perhaps they'll mean something sensible to you?

[Stuart]

nah kev, cam measurements mean fcuk all unless they are done with certain tools ;) lol

steven no one bite me head off but ok you have seen two engines do well with X cam, but youve been given this other cam. Its only gonna cost you a few ? (or ?) to fit and run up on the dyno/take out on the road to see how it really behaves.

bench and dyno results are good ways of gauging stuff but the only proper way to test is on the track/stage.

as for your flat nose cam comment, there arent many "road" cars with them so tehcnically its a fresh shiney NEW hat for us to wear :p

From what you say you claim to be god of the small block so really you should know precisely what this cam will do to any given spec of engine, so asking on here is merely a chance to "lord" yourself over the repliers.

[S_Gault]

original Piper Magnum2 a la 1975 was flatnose!

I build more 16vs than small blocks to be honest. i dont claim to be anything other than someone who tells the truth and that seems to have put peoples nose out of joint

Thanks for your comments Aragorn, I'll dyno it and see what happens.

But i can already tell you that the extra 40odd thou of lift causes major headaches- I have had to machine the spring seats in the head 150 thou, the top of the guide, use a different seal and ive shimmed the solid followers but the rocker geometry is very poor and the follower is running in a bad part of the pad, so I'll have to look at this today before I let this one go.

And Stuart your 1.2 tuning- i'll be interested to see your results, as there is a series here in N.I. for very limited 1.2s and ive built and dynoed 2 this year, we can compare results with your engine.

[Stuart]

limited in what way?

i too had a headache getting a cam with a lairy enough profile, with the appropraite lift (no more that 12mm) and appropriate lift at tdc, but they agreed a custom grind that would be suitable.

the dyno im likely to use is optomistic so ill leave the power calc for after it does a 1/4 mile run and a trip to the weigh bridge.

The truth dosent put noses out of joint, its just some of the "truth" seems a little miguided ie your slating of the Kent AST2 cam where weve seen really good results with one (seen Dan's 1.6 T40'd car in the features with a 14.3 1/4 time).

[S_Gault]

just not a fan of that cam as there are better cams with similiar specs.. the lobe centres are all wrong. thats the truth.

the 2 i did were limited in that no hand finishing of head was allowed and cam profiles were limited to hydralic- bottom ends had to be std and engines had to breathe thru twin chokes.

Steven

[Stuart]

ahh rite, so my engine is totally other end of the scale then lol
+1mm overbore with high compression pistons (pocketed for the valves), deseamed and peened rods, ARP's, 1.6 sized inlet vavles, head work to match valves into the throats etc, 305 deg flatty cam, solid lifters etc. and on T40's

if it makes 100bhp at the fly ill be a happy man.

[S_Gault]

yea and then i'll show you my dyno results.

Send me the shims when you measure them all up and i'll grind them to size for you

Steven

[Stuart]

im only having one shim delivered and then i shall measure up with that one and get the rest sent out. i simply dont have time to be sending stuff all over the place lol The cam etc should arrive on monday for me to begin working on that fun job.

i assume youve had decent power from teh 1200 then.

[S_Gault]

id be surprised if you need the same sized shim on each valve. but offers open if you want it.

especially when you are using a valve from the 1.6 engine hich has a stem length thats miles different from the 1.2 and it drops the follower forward.

keep us posted.

[Aragorn]

i think he meant get 1 shim made to a specific spec

then measure all the clearances vs that shim then get the supplier to grind the rest of them to his measured specs and then post them out?

[S_Gault]

you could be right, i read a bit fast sometimes!

sorry

[Stuart]

kev got the gist of it ;)


no doubt by some magical thing my "silly" spec engine will be down on power compared to the "limited" ones lol


also i looked at some 1.6 valves the other day and they were the same length as my 1.2 ones. BUT other 1.6 valves are longer. hmmm crazy shizzle

[S_Gault]

the 1.6 ones are shorter .

dont measure from the face, measure from the valve seat to the stem

[MC]

The valves that stuart is fitting are the same diameter as those in a 1.6, but are not 1.6 valves. They were sourced specially for the job.

MC

[S_Gault]

makes more sense, just watch the stem material for mismatching

are you fitting inserts to head to fit them?

[Snowface]

http://img.photobucket.com/albums/v642/Snowface-85/day12.jpg

left = 1.6GTE valve

right = 1.4sri valve (fitted to my 1.2b+ head)


(both are exhaust valves)

[Aragorn]

weird how the sri valves have a much tighter angle under the valve head which should mean they flow a bit better

are they stock sri valves or have they been fettled?

and are they the same size as the gte ones?

[Snowface]

Don't think they are GM parts. Both are 31mm standard, the GTE one pictured is a bit bigger at 32mm.

[CP]

makes more sense, just watch the stem material for mismatching

are you fitting inserts to head to fit them?

I can answer thisas this part of the project was my responsibilty as i started it before running out of time. The valves were bought thru as specialist head engineering firm. My original plan was to fit 1.6 ones as a a cheap and easy mod but obviously we found this was a no goer when we got down to it and so i got near copies but with the correct seat face to stem end length. At the same time I had them sort the guides out and fit the correct valve seat inserts etc.

The original idea of tuning a 1.2 was that its a relatively large bore short stroke engine when compared to other vaux engines and therefore should cope with running a load of revs. If its running loads of revs i have concerns about the reliabilty of the valves so they have been left at a fairly std size etc with no waisting. We discussed the possibilty of them stretching and breaking etc and these were the best i could get without getting into the realms of more exoctic race pedigree types - they were fecking pricey all the same lol.

Stu's just got to make sure he doesn't miss a gear.......ever :lol:

[Stuart]

im gonna fit the omegas auto box to it ;) lol

[S_Gault]

the real exotic race ones arent that dear- about 14 quid each

Steven