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New Cam/Heads Combo Sensational

4K views 21 replies 6 participants last post by  Racer 
#1 ·
Heart's still pounding after just going for the first test drive with new SVO Cam A342 (580" Inlet .606" Exhaust) (296 Deg Inlet 306 Deg Exhaust) in the 378 stroker. Taken the 2V's about as far as they will go this time... Fitted a Weiand X-lerator 'cause nothing taller would fit, and blueprinted the Holley 750DP. mmm quite a ride..

New motor so probably shouldn't have caned it so much but couldn't help myself..

Grins all round
 
#2 · (Edited)
That durations not @050 is it? If it is that cam would start so late in the rpm range it'd be drag only.

I've got the same lift but 248@050.

[edit] Just realized that that has to be the advertised duration. Mines 312 inlet and 323 exhaust but you never use those figures anyway.

Brenden
 
#3 ·
Duration @ 50” is 248/258. So what's your idle quality like and out of curiosity what carb/jetting you running? Just been tinkling to try get idle a bit stronger and bit more driveability at 1500-3000, seems like it is fuelling up at those revs.
 
#4 ·
It would be, as that cam don't start till 3800rpm. It will finish up around 7000rpm. Basically you have an SVO copy of a Crane F246. It's a very nice cam indeed.

If you want to launch that car? You'll need to be doing about 4500rpm.

I've got no idea on jetting as mine wa done on a dyno and now I need to get it redone because I've changed the heads.

Brenden
 
#5 ·
I think the SVO grind is pretty old ie touring car spec so reckon the Crane is the copy.. LOL

Yeah it's a nice set up, reckon the engine builder's done a great job keeping the port velocity up because with a 3000rpm stall, 3.23 gears and 265/50 x 14 tyres it's really hooking up nicely. Probably will go to 4.11 gears for the drags with slicks but as a street combo I'm impressed.

But get the feeling the Holley needs tweeking, seems like PV staying open that's why is over fuelled at lower revs.
 
#7 ·
not ford said:
StrokeXD how do you know its over fuleing at lower revs??

Are your eye's are burning at idle?

Also what PV is in it now and whats the idle vac in gear?
Motor feels 'uneven' at cruise rpm ie 2000-3000 with a continous almost stumble feel to it.

A few times the carb has flooded because of poor needle and seat control at the fuel pressure I was running and this excasberated the effect so I'm assuming too rich and not too lean.

Also the exhaust pipe is sootie after a slow cruise, and outside of plugs likewise though centre electrode gets almost too white after a hard run..

Installed a Holley high flow PV 145 - size 45 as vacuum at idle out of gear is 6-7 inches, but can't get it to idle in gear long enough for a reading. Reckon the next thing to try is size 35 because it could be opening at idle and at the above revs when under load.

My gut feeling is its running too rich on primaries and too lean on secondaries with a dodgy, or perhaps too high, PV...

Possibly could get it all sorted out easy with a competent dyno analysis but have been a bit disappointed with the last few I've had over here in Perth. One of the more reputable places spent a day on the car with my previous motor combo and I ended up changing all the specs back the way I had it. Seems they tuned it for a technically correct air/fuel ratio rather than outright grunt like I'm after.

Don't suppose anyone out there knows of a decent dyno tuner in Perth?
 
#8 ·
Cause your cam is so large you're supposed to size the PV at 1/2 idle vac + 0.5. Striaght away from this you can see you need 3.0 (do they exist never needed one that small, otherwise 2.5).

Is it hard to get the idle mixtures right?

Also what are the exact mods done on the Holley?
 
#10 ·
xacoupe said:
considering the crane is .570 / .590 it's not likey to be a copy.
Even though the dyno tuners have been somewhat dodgey, have they given you a power estimate?? I suspect it's a bit new for 1/4 times yet !
Yeah was just taking the piss on the Crane cam...

Spoke to a few (new) engine dyno guys today, the advice is to wait for 500k’s up. Soon as I get 1000k's down it will be down the quarter.

With right gearing it should be in the 11's, but with my set up somewhere in the 12's. Been scaring the shit out of me. Loads of mid-range, breaks the rear wheels loose with very little effort.

Having fun!
 
#11 ·
not ford said:
Cause your cam is so large you're supposed to size the PV at 1/2 idle vac + 0.5. Striaght away from this you can see you need 3.0 (do they exist never needed one that small, otherwise 2.5).

Is it hard to get the idle mixtures right?

Also what are the exact mods done on the Holley?
Got the idle as good as it’s going to get..

Spent the day trying different PV combinations. What I learnt that I didn’t know before:

• Stay away from Holley’s range of high flow PV’s (135, 145, 165 etc series). Unless the metering block is modified then they can just stay open; and
• The common method of going 1.5-2.0” below vacuum at idle for PV selection is not always the best thing to do. With a big cam and f.. all vacuum at idle this method will stop the PV pulling open at idle but can also cause a high speed lean out...

So went from 145 (Holley’s high flow 4.5) to a 55 (5.5) and mid range/cruise performance is a lot better.

Still buggering around with jetting. After the last run on 75 jets in primaries got a sootie plug, so just about to try 73’s..
 
#12 · (Edited)
STROKEXD said:
Yeah was just taking the piss on the Crane cam...

Spoke to a few (new) engine dyno guys today, the advice is to wait for 500k’s up. Soon as I get 1000k's down it will be down the quarter.

With right gearing it should be in the 11's, but with my set up somewhere in the 12's. Been scaring the shit out of me. Loads of mid-range, breaks the rear wheels loose with very little effort.

Having fun!
I doubt you'll get into the 12's. considering the engines understalled with a 3000rpm histall. I used to run the same spec'd cam with a 3500rpm. Thats what I ran my 12.95 with. I now run a 4500rpm histall. Optimum to suit the cam is 4300rpm.

As for diff gears. 4.56 is optimus but I am trying my luck with 4.11's as they were there. I probably end up with 4.56 anyway.

The only differences between our engines going by your user name is:

a) I run 351 crank and rods guessing your run a stroker.
b) I run allumimium heads. Which is where I make my power from. 11.2:1 compression on pump fuel is nice.

[edit] my auto had a few issues aswell and I also had slicks. I'm interested to see what it does run. Dyno prior was 230rwkw with the 2V cast heads.

They're right get the 1st 1000k's done and go for it.

Brenden
 
#14 ·
Sounds like it will be a pretty quick car.
 
#15 ·
Brenx I’m running an XD which is almost a couple 100kg’s lighter than an XB. The extra stroke brings up cylinder pressure a lot quicker, piston is at TDC longer with the change in centre to centre length with Chevy rods,. So overall makes a bigger difference to engine dynamics (especially torque) beyond what the extra 28 cubes would indicate. Even at a conservative 1.1 HP per cube ratio the increase in cubic capacity alone is worth 35HP, but the net effect is much greater when you get into the science of Cleveland inlet issues and cylinder filling. Basically the same cam doesn’t read as peaky in a stroker as it does in a standard stroke Cleveland.

It’s a dominator ‘3000’ stall with is actually stalling about 3800 with the new motor combo behind a very prepped C4 that I hope holds together. The 3.23 rear gears with current 265/50 x 14 tyres (620mm diam) equates to about a ratio of 3.7 gears when you do the maths with taller drag slicks (eg 26.5x8’s on 15 inch rim).

Considered the 3V heads but reasonably convinced with all the development my 2V’s have had I’m within a hairs whisker of the 3V’s flow and velocity figures, and about $1000 cheaper to boot.

Been driving worked Cleveland’s for 20 years, and racing em for the last 5, so my guestimate of mid to high 12’s with the current gearing is pretty spot on. Rear end gearing is way off quarter mile ideal, so anticipated 11’s with the right gearing seems pretty right especially as a few street cars over here are running 11’s with the same stroker/cam/head combo in XY’s.

The current ratio is very streetable and having loads of fun driving it which is what it’s all about anyway.

Cheers
 
#16 ·
The only way you'll find out is the way everyone does it. Test, test and more testing. Let us know what you run. As I am very interested to see a time, even if the setups not ideal. Either way it'll be quick.

My setup started off running 13.6's, then 13.4's then finally did a 12.97 and 12.95. I was alway told it should have gone low 12's but I take that with a grain of salt.

I am not a big fan of cast 2v heads, been there done that, wasn't happy. Max flow I've seen from them is to support 570hp flow. Most decent head porters won't state more than that.

I did my comparisons on the 3V's, comparing to 2V's (worked/ported) and 4V's with the same. I am more than happy with 680hp flow. Even with the stuffing around. All depends on what 3V's you compare to EM (185cc) or 218cc.

DOH! I forgot about the stroker dropping about 500rpm from the cam. ;)

My aims 300rwkw or more which the 3V's do help with and my 2V's didn't.

I spent big on the 2V's and I've spent about the same for better performance with the 3V's.

Streetable couldn't agree more. I did 20,000k's street use before I de-reg'd mine.

It's more than possible that it'll run 12's but only if everything is right.

My 2V setup made 450hp but the 3V's are yet to see a dyno.

Didn't realise the XD's were so light. Just did a search on the web to find the curb weight. Much lighter than my 1593kgs.

All the best,
Brenden
 
#17 ·
Yeah cheers Brenden it's always quite a journey hey? And it's amazing just what needs to be done to pick up a few 10ths on the time card...

Spent most of the day actually trying to get the 3 month old MSD pro-billet dizzy to work properly. Been impressed with the grunt so far but a timing check up last night revealed I was only getting about 5deg centrifigal (on 20deg static). Way inadequate even for 11:1.

Was dumbfounded when I changed springs and stop bushes 3 times and made no change. For some reason the weights were sticking when the motor was running but not when shut down or dizzy out of the car.

Cut a long story short turned out to be the dizzy shaft being pulled into the motor at high revs causing the centrifigal plates to jam against each other and bind up. Set up incorrectly from the factory I guess, but not highlighted before now perhaps because of very slight difference in camshaft end gear and even the coat thickness of new paint on the block. mmm weird. Hopefully to be fixed tomorrow with some bushes to change the end float.

Just curious, what max exhaust primary pipe can the 3V's run? Can you fit 4V size headers ie 2inches or bigger or are you on 2V sizes ie max of 1 7/8 primares?

Awaiting delivery of some pacemaker 1 7/8's extractors with HPC coating. Feel the motor is limited now with the 1 5/8's on there now.

Also wondering if you running the usual MSD6AL set-up? I've found heaps of gains with this unit and increasing plug gap to about 1.1-1.2mm (from standard 0.8/0.9) with good combustion chambers.

because do it's stuff
 
#18 ·
xacoupe said:
going to be a weapon once you run it in !!
Pics and more specs!!
The more tough clevos the better !
Yeah got to do some new pics, spotties (yuk) have gone, grill now painted body colour and has a Hornet scoop fitted without the base plate, looks heaps better than the pic here albeit a few stone chips around the rear quarters..

Specs are:
351 Cleveland block 30" with offset ground 4MA crank to 3.7 inch stroke (standard 3.5 inch) to give 377.5 cubes
Chevy 5.7 inch rods
ACL psitons - specially made Chev rod in Cleveland block combo
Extensively ported and polished 2V heads, 1 piece 4V exhaust & 2V inlet valves, Crane 1.73:1 roller rockers, big block Chev pushrods
Compression 11:1
SVO Cam M-6250-A342, lift 580"/606", advertised dur 296/306, dur @ 50" 248/258
ARP rod bolts etc
Ported Weiand X-erator manifold + 1 inch spacer
Holley 750DP choke horn removed with some porting around the neck
MSD 6AL box, MSD Pro-billet dizzy, blaster coil, Accel 8.8 leads
Pacemaker 1 5/8 extractors to be upgraded this week to 1 7/8
C4 reverse pattern and full manual valve body with lots of other magic that I don't really understand to handle up to 500HP I'm told...
 
#19 · (Edited)
With the 3V's it all depends on your exhaust porting. They recommended max is 1 3/4" pipes, which is what I had on the 2V heads. I still run my Pacemaker 4-1 1 3/4" piped extractors PN 4070.

You can run 4V pipes without any issues most street 4V pipes are either 1 3/4" or 1 7/8".

Ignition wise you cant beat the motorcraft stuff. IE XD style electronic ignition (same as ICE ignitions use). I run a US Ford motorcraft electonic distributor. It's nothing special but it does exactly what is has to and when it has to. I've been tempted to try a larger plug gap as my plugs came wth a factory 1.1mm gap. I run .9mm

You'll feel a decent power increase from the 1 5/8 pipes to 1 7/8 pipes. As the 1 5/8's will be shrouding your exhaust port. So expect at least a 20-50hp increase.

Brenden
 
#22 ·
Like i said, you never can tell. I gained 36rwhp by going from 1 5/8 to 1 3/4. Not that i hold much faith in dyno numbers.
An engine is like a pipeline. Its the point of most restriction that holds everything back that must be found and freed up. Making something bigger doesnt generally work. Finding the cork in the system and removing it does.
 
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