I just listed on Ebay the Holley Street Dominator intake manifold that was used by Tim Meyer in the Dyno test of his 400 motor. The listing # is 8011610010.

 

Hey Danlee can you throw my build in and see what I get with this puny cam?
here are my specs (off the top of my head)

71, 400 dearborn block, bored .020 over, ertyl flatops .050 in bore. 71 heads with 2.19 intake 1.71 exhaust (tuliped and under cut), 3 angle valve job, hardened seats, mild blending of bowels. Titanium locks and retainers. Arp everything on the short block. Hi-volume oilpump, straight cut timing gears, hi-volume alloy water pump, rebuilt 71 points dizzy with pertronix ignitor II points, coil and wires (timed 8*tdc mech, 12* with manifold vacume for a total of 36 at 3000rpm). Edelblah manifold and 1405 carb (8% leaner on cruise), hedman headers 2.5 inch extension tubes to dual flowmaster 40's with a crossover tube. 4inch underdrive race pulley, Heavy duty flex fan, autolite 24 plugs gapped at .050, hi-volume fuel pump. Old cam was a comp cams 268H timed straight up and I matched the coverter to it, pulled 14 inches of vacume. But now I'm driving her everyday to school, so I put a puny clevete cam in her 270/290adv I/E, 192/198 .050 I/E, 427/433 Lift I/E, timed 4.5 degrees adv, pulling 21 inches of vacume.
I believe the heads are 75.4 cc'c not 78.4. With a 4.1 bore .039 head gasket, it comes out to 9.8cr for the 75.4cc chambers adn 9.55cr for the 78.4cc chambers. (if that changes any of the power numbwers) also 109 intake lobe centerline, 111 exhaust lobe centerline. 110lsa and 109centerline for 1* advance plus another 4.5* in the timing gears.

If I'm missing anything let me know.

 

Kofenjager,

I can simulate it using published head flow for 351C-2V heads, but I really need head flow data to get it right since the heads have some work done.

Dan

 

I was told a 5-10 cfm increase across the board for the bigger valves and the work that was done. I would assume these numbers would be towards the lift areas that already flow the best. But you can add a few cfm in the lower lift areas and not worry about lifts higher than .435. I would think this could be fairley accurate. I have a web sighte somewhere that states the flow increase for 4V valves, but thats for stock valves not ones that are undercut and tuliped, wich I beleave helps the flow, a bit. A wee bit, a drill bit, or whatever. Thanx.

 

danlee and kop: should i go with bigger valves as well as port&polish the exhaust and cleaning up the intake a bit? I was thinking of porting intake as well since the fuel is vaporized but probably won't gamble on my hypothesis that it would be ok.

ANd: we have a winner re; cam. Thanks danlee, would not have been possible without you. I will review the TMI results again on that intake...may bid?

 

I went with the bigger valves because they were the same price as stock valves. I wanted to get away from the two piece valves, and get something in stainless. I sent them off to power heads and hade 4V size valves installed with hardened seats. Like I said it was the same cost for either 2V or 4V, and I was told the 4V would give me better flow so it was a no brainer on my part.

 

Larger intake valves will help the flow. There is some evidence that larger exhaust valves do not help, because of cylinder wall shrouding.

You can port and polish the exhaust,and clean up the valve pockets on both intake and exhaust. Don't polish the intake. While it may be OK to have polished intakes with Propane, it is hard to unpolish a port.

Definitely get rid of the two piece valves.

 

Is there evidence that increasing size of exhaust hurts performance or economy? How does increase valve size affect economy- I understand flow increases consumption but little else.

 

Increased flow at low lifts should help economy. It certainly improves performance. The valve size will affect the flow at low lifts.

Fuel consumption is affected more by Valve timing and overlap, less by head flow.

 

Converter and gears effect economy alot also. I lost 3mpg with my high stall converter, but gained plenty of performance. now I'm doing the opposite. Smaller cam, tighter converter. It's sitting in my living room, and it should be in by tomorrow night.

 

I'll order the kkit through a friends company tomorrow- lists at comp for a little over a grand and I'll get it for 680. Now I'm still a bit confused by the roller rocker thing where comps best- which are made of chrommoly are said to be not so good while the alum scorpions are awesome. Heard again from another builder that aluminum flexes and is not a good deal...like he warned me not to get them....but i trust you'all and will go to tmi for some scorpion pedestal rockers. Oh the money...it hurts!!!!

 

So did you do this yet?

 

Hello Roger.
Your build sounds great! I would have loved a roller cam in mine.
You may remember me from earlier posts on a propane-fuelled 400. I currently run one in an XD Fairmont sedan. It has been trial and error with this motor, especially down here in Oz, where very little information exists because the the 400 was never put into local vehicles.
My 400 has a solid cam (Crow 21626) Adv. Dur. 278 I/ 282E; 238 I/244 E @50 thou; GVL 0.56 I/0.57E. IN 30/68, EX 72/30. The heads are 2V open chamber ported and polished with 4V stainless valves. Crane Energizer roller rockers. Pistons are Tim Meyer's increased compression height Hyper flat tops (CR approx. 10.5-11.0:1). Have 4 into 1 Pacemaker extractors, dual 2 1/2" exhaust with dual turbo mufflers. 9" rear 3.89:1 ratio.
There are several things I think you should be wary of Roger. Firstly, propane-or propane/butane mixes- are different to gasoline. Propane occupies more volume than the gasoline vapour. Single plane manifolds appear to suit propane better and lead to more equal filling of cylinders. Dual plane manifolds are used but the middle divider is often reduced to effect the same result. I have run single plane manifolds on the same car with a 351 Cleveland and the 400 running propane and have not noticed a sacrifice in bottom end.
Secondly, I think your 400 is going to be under-carbed and may run too lean at higher revs. I run a dual Gas Research set-up with one carby acting as the primary and the other as a mechanical secondary. The primary flows 440cfm and the secondary 480cfm. Initially I had 840 cfm total(400 cfm primary and 440 secondary) and the motor would ping at higher revs-even with straight propane. By increasing the total flow to 920 cfm I was able to eliminate pinging and increase torque by at least 20%. In other words, a motor like yours will want more propane at the higher revs than your 600-650 cfm carby can give.
I had the car dynoed recently and peak torque was 6850 Newtons, peak power 212.2 kW. This was for 920 cfm total flow. For 840 cfm peak torque was 6350 Newtons and peak power 196.8 kW (I'm sorry don't have the conversion figures to foot pounds and HP).
I reckon sticking with your 302 closed chamber heads and machining your pistons to suit a desired CR is the way to go. I wish I'd gone that route. Because straight propane is scarce here and mixes with butane are common, I cannot advance timing beyond 10 degrees BTDC with out pinging.
Hope this helps.
Craig

 

I did change some aspects of the build- lowered the compression to an arguable 9.5:1 with the quench of myer's kb pistons that will afford solid quench...I'll be breaking it in with pump then adding the propane later. This is an older thread and I have the specifics of the build elsewhere. I'm getting the balanced rotating gear on Monday and will start putting it together...long drawn out process unfortunately.

Thanks for your tips...I'll be checking the carb closely and may end up getting a different set up.

 

Hey Kionga.


Seems we have similar build spec wise. i too am running 11:1 but i used kb cleveland piston and i am running a roller cam with 2 ohg mixers on an adapter with a seperator between so the rear mixer works with the secondaries. you are correct that this is trial and error,not much info any where though i have found a few forums that have some good info. No dyno near me so i bought a gtech accelorometer, which is not too accurate due to so many variables, ie wind, vehicle drag, road resistance . It gave me 270 hp on the ground which i feel is conservative. The motor is in a 86 f150 which weighs 4800 lbs last time at the scale. I am running 3.89s with a 29 inch tire. Even with my camper on which i think weight at least 1200lbs i experience no pinging . Timing is 14 initial and 34 total at 2800. I feel that the money i spent on the msd distributor, 6al box and blaster coil was a good investment to get the propane lit.As for intakes , i have run both single and dual and am running a dual currently. i have found low end suffers on a heavy vehicle with the single plane. I was goin to go back to a single on this last build but my parents couldnt seem to locate my spare intake . My best 0-60 time is 6.9 secs which is pretty decent considering the weight. I included a few pics if you interested and i would like ot seee some or your car as well if you have any.For exhaust i am running duals with flowmaster 50 series which seemed to improve power but are damn loud, am lookin to add some resonators in the future.Future upgades i am contemplating are dual lines which is no biggy as i have 2 tanks. and a larger throttle plate , currently 750 mechanical secondary. I have a turbo from a 7.0L idi turbo thats been tempting me but that will have to wait a bit as i will have to lower the compression. cant hurt to dream lol.

Ne way is great to read about others having fun with propane, enjoy you build and i look forward to some pics.