318 combo

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Chillipepper - I have thought about turbo, but it will totally blow my budget. No pun intended. The quality of propane in Oz is a bit hit and miss. The butane content varies which affects the octane (it's rarely pure propane). With iron heads I think 10:1 is about the highest safe static compression without running a massive cam.

Poison - it's pretty much impossible to find closed chambered heads here, and the price of head work here is very expensive. To just buy a set of heads and have some basic work done on them I think I'd be spending just as much. I'd rather spend the money on the EQs. I'm running a stock bottom end so the smaller combustion chambers should help a bit with compression as well.
 
Thanks all for the advice - I ordered a set of Iron Ram heads from Hughes yesterday. Getting all the other bits together now - just wondering if anyone knows where I can get some cheap Magnum valve covers. LA covers are like $30, but for some reason I can't find Magnum covers under about $170!
 
Pm me.I have a stock set.Yours for shipping only. If running aluminum rockers,won't clear. If you use a really good gasket set, LA valve covers,work fine. Take your pick.
 
Abodybomber said:
Pm me.I have a stock set.Yours for shipping only. If running aluminum rockers,won't clear. If you use a really good gasket set, LA valve covers,work fine. Take your pick.
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Yes to LA covers, I have had good luck using LA covers with a LA gasket on the cover and an additional mag gasket on the head.
No leaks, and the covers have been off several times.
What may attribute to mine working is I have studs in the heads for the covers, so you don't pinch gaskets when taking them on and off.
 
Trying the same myself,Sire land. Have a set of nice Holley finned v.c.s.
 
Stud them, don't even waste you time with the bolts.
Been there...
 
quick question - does anyone know roughly what length pushrods I'll need for the EQ heads on an stock unmolested LA block? I don't mind buying adjustable ones if I can get a ballpark length.
 
i think i'll just measure once its assembled and figure out pushrod length then. one thing I have been thinking about is the cam. I really like the Howards cam recommended earlier - 208/214 @ 50 .479/.494 lift - but I'm concerned that with 1.6 rockers the lift might be a bit high, bringing it up to .511/.527

I don't know if a) short duration and high lift might be bad for valvetrain longevity, and b) if there are any issues with running >.500 lift with stock rockers and a flat tappet cam.

Any thoughts?
 
pick a less aggressively ramped cam and let the higher rocker ratio to the rest. That's what I'm planning with my own Magnum conversion. Finding the right cam is tough
 
0.455 lift with 1.6 ratio gets you about 0.485in lift which wont stress the springs or rockers but that's not alot of duration. It depends on what you want out of it. But it should make 320hp easy
 
I'd recommend talking to a few cam grinders about a LPG low comp grind to suit your needs. Your motor is going to be unique, you need a unique cam.
 
I'll definitely do that Frosty. I was thinking that a high-ish lift short duration cam could work well in my low comp engine - similar to the Hughes whiplash cams but a little less radical. I want to keep the torque band down low, and from what (little) I understand about cams, as duration increases the power band moves up the rev range.
 
Everyone is shut today, so i'm just tossing ideas around. The more I look at the Lunati 216/216@50, 454/454 lift the more I like it. 110 deg LSA which should hopefully up cylinder pressure a bit, decent lift, low duration. Am I right in thinking this should make for a fairly responsive, torquey motor? I know propane tends to tame cams a bit and make them a bit more streetable - I'm thinking the lunati might be a good compromise and be pretty close to what the Howards cam would be with 1.5 rockers.

http://www.summitracing.com/parts/lu.../make/chrysler
 
Given that you're looking at a 8:1 compression on LPG, I would be surprised if a cam manufacturer like wade or crow don't recommend a cam with more duration (and therefore possibility of more lift) cut on a 112 or even possibly 114 LSA. maybe even with a few degrees installed advance to boot.

I'm no expert on camshafts, but I would be trying to get that IVC happening early early early!!
 
Well, I spoke to Crow, Wade, and Clive cams today. Bit of a mixed bag. All recommended something in mid to high 400s in lift and low 200s duration at 50 (208-215). Where they differed was on LSA. Crow said that LSA should be 112 for better vacuum as LPG is heavier, whereas Clive and Wade thought 110 would be a good middle ground. I still like the idea of upping the cylinder pressure if I can, so I think I'm going to stick with the Lunati. It's got a touch more duration at 216@50 and with 1.6 rockers works out to be .484 lift. I'm pretty much sold on it I think.

I've got a stage 3 Heatseeker cam at the moment (no idea what that means, company has folded) that is an absolute pig. Even with a stall it's just slush until about 3000rpm - i really fricken hate it. I don't want to go too crazy on the duration because I want to stick with a stock converter and keep the torque nice and low. I've got a 2.92 rear end and I do a lot of highway driving so really, I just want a nice torquey crusier that can get off at the lights.
 
according to the internets.

Your cam should be a Heatseeker "Challenger" HS30J with the following specs:

*Idle-Fair
*Rev Range-2000 to 5800
*Trans-Any
*Gross Valve Lift- IN 442 -EX 450
*Cam Lift--IN 295- EX 300
*Adv Duration--IN 288 - EX 288
*@.050 Duration- IN 222 - EX 222
*Valve events -IN 37-71--EX 70-38

(108 LSA)

To be honest, If that is correct then there's no reason whatsoever why your cam should be a pig.
 
Thanks frosty. interesting to know. maybe the cam was installed retarded or with no advance. it was in the car when I got it. either way, I've got either a collapsed lifter or bent pushrod from the noise the top end is making so the cam is getting the flick. even before I converted to lpg it really didn't have much guts.
 
Well, I bit the bullet and ordered the Lunati along with everything else I needed. I'll let you all know how it goes. Thanks to everyone for all the advice.
 
318Goon said:
Well, I bit the bullet and ordered the Lunati along with everything else I needed. I'll let you all know how it goes. Thanks to everyone for all the advice.
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What size valves did you get in your EQ heads? in my experience 2.02 intake valves take about 3.5cc out of combustion chambers.

When the heads arrive it is worth measuring the chambers and also how far the piston sits down the bore at TDC.

with some luck you might be able to get some .020" copper head gaskets to bump up your compression into the mid 9's.
 
I got the EQs with 1.92/1.60 valves. Didn't want to go too crazy with valve size because I wanted to keep the torque low. I thought about thinner head gaskets, but that would probably mean machining the block (and maybe heads) to true them up. I'll check out the deck height when the heads are off.
 
Good came choice. You need to order custom push rods anyway. The Hughes spring setup,on stock EQ's good to .530 lift. (assembled my own set,measured personally.). Order the Comp Cams adjustable pushrod. Youtube has a Comp Cams video ,watch it. Depending on valvetrain,might need lash caps. I used Empi vw on mine. Still need to make time on the valve covers,BTW. P.S.: The E.Q 58 cc chambers,1121g Mr Gasket .028" gaskets,worth .5 in compression.
 
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