445 replies to this topic

[LXCHEV]

I can relate to that Tiny - I have literallty 1,000,000 other priorities in life at the moment preventing my from racing and having fun!!

On another note - guess what guys, Rick (TORANR AMORE) tied the knot last Saturday. (Congrats RICK!!!). I was lucky enough to chauffeur him to the church. He had a nice line-up of wedding cars (thanks to the boys from Eastside Cruisers for offering their rides)....

[LXCHEV]

Ok couple of minor updates on the old girl.

Had my mid-section of exhaust removed, and replaced with a nice new stainless X-pipe (it replaced a really crappy reverse facing balance pipe). The exhaust note has definitely improved, both inside and outside the car. Much smoother, and the crackly/thong-slop seems to be completely gone. So very happy with that.

After that it was onto the dyno for the first time. I've clocked up around 2,000km's on the new engine and didn't know what to expect. Results came in, and I was disappointed - not that I was chasing numbers - but it put down 230 rwkW. That's no more than my old engine - with either my old hydraulic flat tappet or solid flat tappet. (New engine is a hydraulic roller - Comp Cams XR288HR - 236/242 @ 0.050 on 110LSA with .555/576 valve lift). I've estimated that 230 rwkW eqates to approx 440 HP at the Flywheel. I thought this engine might go high 400's (I see no reason why I couldn't even hit the magic 500HP / 500 ft lbs)...

Anyway, had a chat to my dyno guy, and we've agreed the missing power is most likely in my old Pro Topline iron heads that were repaired after my epic blow-up. Being on a mega tight budget I kept these old heads. With the cam grind I'm running, apparently I really need better flowing heads to see the real potential. Makes sense.

I can't remember if I already posted these figures or not, but this is what my heads flowed:

LIFT 0.200 0.300 0.400 0.500 0.600 0.700
IN 131 178 214 233 241 246
EX 98 133 158 178 191 193

Those numbers are down on the factory figures from Pro Topline - as much as 30cfm in certain areas. With appropriate porting, I'm told we can easily get at least 25cfm back out of them.

What I'm curious to know is what effect this might have?? I'd hate to spend the cash to see little or no gain. How does cfm equate to HP? If I decide to chase more power, would I better off just buying some alloy AFR's (which have higher flow figures again - eg the 195cc street heads flow as much as 40cfm more than my heads).

I should just stop thinking and be happy - but it's the nature of the game to always chase that next target down right! Will be interesting to hear what people think.

PS. Just remember the basics of my combo are as follows:

381 SBC
10.5:1 comp
Comp Cams XR288HR Hydraulic roller
Pro Topline 200cc iron heads
RPM Air-Gap dual plane
Holley 750 Ultra HP
1.75" -> 2" -> 2.5" Tri-Y's

Edited by LXCHEV, 12 May 2012 - 11:04 PM.

[mr5000]

^{get a big money tin and start saving for some afrs you no ya wanna 230kw is enough for the time being wouldnt suprise me if you hit high 200s with decent heads
every engine builder ive spoken to reckons the heads are the chevys biggest weakness till you go alluminium mind you i dont think holden heads are that much better but smaller cubes seems to work better}

[LXCHEV]

Blown V6Hatch - If those Dart heads flow decent numbers, combined with a Victor Jnr, I'd guesstimate your engine would push very close to the magic 500HP mark. To answer your question regarding my car - it drives like a dream.... stacks of torque & heaps of grunt. It's very timid to drive, not aggressive at all, but when you really put the boot into it, she gets up and boogies. I need to race it to see where I'm sitting.

Liam - just out of curiosity, what's the company selling those cheap heads? If I do ever upgrade though, I'll be buying alloys for sure. I love the look of the AFR's, and after seeing a couple of mates with them, and seeing their insane results, I'm totally sold!

Mick - thanks mate. Yeah I'm just rapt to have the beast back on the road. I get it out every chance I get, so whilst I'm not doing heaps these days, at least it's not just collecting dust. Itching to get back into some kind of driving events though.

Ryan - haha I love the money tin suggestion. I'm already onto that, but I'm saving for a new set of front Convo's & tyres, fresh carpet, rear tyres, Tru-track, front spoiler and flare, fresh paint etc etc etc.... it's always a long list, LOL.

[LXCHEV]

My current heads are "Pro Lightning" from Pro Topline - which were taken over by RHS and I believe renamed to "Pro Action". So it's gotta be the same company! I bought these heads new over 10 years ago, because they were priced well - good bang for buck! Mine are only the 200cc versions, but the 228cc versions are advertised to flow just under 300cfm @ .600 lift as you mention. That's from my very old catalogue too - so the more recent versions have probably improved by now. These heads have always had a great reputation as being cheap but serious performers.

[LXCHEV]

Mild heart attack during the week..... had the beast out and oil pressure gauge was suddenly showing between 10 and 20 PSI, whereas it usually sits around 40 - 60PSI.

I was mentally preparing myself to pull the engine and embark on a rebuild after only clocking up 3,000km's so far on this engine. But after fitting up a mechanics oil pressure gauge, the pressure was steady at around 65 - 70PSI cold, and still holding 60PSI warm. You bewdy!!!

The electric gauge will finally be coming out, and I'll be fitting an old fashioned mechanical one now. I'm converted

Getting itchy to race the car too.... no high hopes, but just wanna get it on the race-track.

Driving it up to Bendigo All Holden Day in a couple of weeks too. Look out for us there if anyone is going.

[LXCHEV]

Yeah the old motor was putting out pretty much the exact same kw's, but it had a heaps bigger solid cam. So it'll be real interesting to see what this engine runs with the hydraulic roller. Previous best was 11.77 @ 115MPH. As long as I stay in the 11's I'll be rapt. If not, I'll be forced into more mods, LOL.

Cheers mate.

[LXCHEV]

Cheers for all the info and comments mate! Yeah I'm still torn on the grill and headlight change, LOL. It's great hearing comments like yours.

[Tiny]

Hey Brett!
Thank goodness that the oil pressure was not a problem! *phew*!!

If your chasing a little more flow, I recall speaking with my engine builder when I bought the same heads you have.
He said the flow was so good out of the box porting wouldn't gain much.
But!!
You have te heads, so you COULD give it a bit of a go.
I've gotten the inside info on a few porting techniques and what was said above was spot on!
It's more about cleaning up what's there than anythng.
Do NOT go huge!
Clean up the radius on the short turn of the port, around the guide and just a little outside the port.
You will need a valve service afterward cause there is no doubt you will mark the valve seal face!

I gotta run, but drop us an email when you get a chance!

Good luck dude

[LXCHEV]

Hi Ryan,

 

I still prefer old school carb engines over EFI, especially since my car sees more limited km's these days, plus at this stage I'm still sticking to the traditional old school muscle car look overall.

 

Having said that - EFI - whether that's a retrofit to an old school engine, or a complete swap to LS1 or similar is appealing for smooth, reliable, more economical drive-ability.

 

When it came time for my engine rebuild after the blow-up, I never considered LS1 simply due to the cost of the conversion. I know it's gotten much easier these days, however there is still a very significant cost involved to do it well and do it properly. So much would have to change - exhaust, trans/box, tailshaft, wiring, engine conversion/mounts/sump, plumbing etc etc etc.... (snowball!!). I wonder what the average cost is these days? You're in a much different boat though, as you'd be converting from a 6 cyl. So the cost difference might not be much different.

 

PS. Since this thread has been dragged up from more than 2 years ago - not much has changed with the old girl - besides a move onto the Club Permit Scheme. $70 rego, it's the best thing I've ever done - although I certainly miss the custom plates.

 

Here's some random photos from recent times, just out and about having fun.....

 

The kids are growing up real quick, and we've been involved in some weddings which is always great fun....

 

 

 

 

 

[LXCHEV]

Mate I did exactly the same thing when I first built mine. I installed the body kit and wheels, suspension, and painted it, but retained the 202 six banger for a while first. All the go-fast driveline bits came later on as I saved the cash. The only exception was the 9" conversion, that came very early with the 6, as I was sick of breaking Banjo diff centres and axles. Banjos don't like 10" wide rims with a manual being driven by an eager 20 year old!