New engine build thoughts

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gumper

gumper

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Finally, after 13 years, I have my 408 torn apart for a rebuild. Going to change some parts to go faster. This list is what I had, and what’s going to be now:
LA 408 Chrysler
3250 with driver
Running at 5300’ elevation
Generally race 1/8 mile at home track in Montana, low 7.30s at 93 mph. For comparison of air density it ran 6.92 in Seattle last year in the 1/8.
New cam specs are .588/.600 lift, .250*/254* @ .050, 108 LSA (Was a Mopar Purple Shaft solid cam, intake and exhaust .557 lift, 252 duration @ .050, 110* LSA)
Ported Edelbrock Performer RPM aluminum heads (280/240 flow at .600 lift, 65cc chambers, 2.055/1.60 valves)
Was 9.9:1, now it will be 12.5:1
Weiand single plane intake
Going to use TTI 1 7/8 to 3.5” headers, up from Hooker 1 5/8 to 3” headers it had
Rons toilet injection throttle body on methanol (~1400 cfm)
1.5 rockers
4.30s, 28x10.50 tire

Based on what it’s going to be now I’d like opinions on what it may run. Going from the 9.9:1 to 12.5:1 compression especially with alcohol will be a huge difference. I can’t really believe it ran as well as it did before.

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I like where you are going. Not sure what intake it is that you have, but I know moving the nozzles up from the intake rail makes more power. Don’t know what you have for and idle check spring, but as the nozzles move away from the valve, you have to up the idle fuel pressure to keep the idle clean.

Are you using all Ron’s stuff, like the barrel valve, by pass and stuff like that?
 
yellow rose said:
I like where you are going. Not sure what intake it is that you have, but I know moving the nozzles up from the intake rail makes more power. Don’t know what you have for and idle check spring, but as the nozzles move away from the valve, you have to up the idle fuel pressure to keep the idle clean.

Are you using all Ron’s stuff, like the barrel valve, by pass and stuff like that?
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I haven’t been using a bypass since the engine rarely went over 6200. Probably will be using one this year though. Was running 29 nozzle jets with an 82 pill. I put my nozzles about an inch above the end of the intake runner per their instructions. It’s just a Weiand Xcellerator intake I did a port match job on. I have my doubts that a high rise intake like a Victor would change much since it’s already spraying fuel directly on the valves.
 
gumper said:
I haven’t been using a bypass since the engine rarely went over 6200. Probably will be using one this year though. Was running 29 nozzle jets with an 82 pill. I put my nozzles about an inch above the end of the intake runner per their instructions. It’s just a Weiand Xcellerator intake I did a port match job on. I have my doubts that a high rise intake like a Victor would change much since it’s already spraying fuel directly on the valves.
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If you are using the Ron’s barrel valve, they should have a 2-3 pound spring in there. Mine was shipped with out one, and it was a royal beeeeeeotch to start hot. I figured it out when I had to rebuild the barrel valve and I was making my own valves. Without some pressure restriction, they don’t start well hot, and they idle dirty. Well, dirtier that they should.

I ditched most of the Ron’s stuff, switched to a Kinsler quick change main jet can and that’s where the idle spring was. I ended up at 18 PSI in the idle check, 80 PSI at the nozzles at 8500 RPM and I opened the high speed at 62 pounds.

I should have added another bypass. Then I’d have opened the high speed at about 50 pounds and the pump loop (which I hate calling it because I was never fond of adding fuel back into the inlet of the fuel pump but that’s what everyone else calls it) would have opened at about 70 pounds.
 
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My whole setup came from Killer Rons. It starts well when it’s warm. Usually open the shutoff valve, hold the throttle half way open and crank a few times. Only spring I know of is the one holding the pill in.
 
pittsburghracer said:
How’s your oil look when you change it and how often do you change it.
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Oil is always much cleaner than a street car. Dark amber in color as you can see on the cylinder walls. I change it at the beginning of every race season, and that’s it. It never has moisture in it. I run Amsoil 20w-50 with dual remote filters.
 
gumper said:
View attachment 1715511263 My whole setup came from Killer Rons. It starts well when it’s warm. Usually open the shutoff valve, hold the throttle half way open and crank a few times. Only spring I know of is the one holding the pill in.
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Isn’t there a check ball and a spring behind the return line fitting?? Been awhile since I had a Ron’s barrel valve, but IIRC that’s where the idle check spring is.
 
yellow rose said:
Isn’t there a check ball and a spring behind the return line fitting?? Been awhile since I had a Ron’s barrel valve, but IIRC that’s where the idle check spring is.
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Yes, now I know what you are talking about. I’ve never messed with them. Only way I adjusted the idle was with the linkage.
 
Going up in compression will be killer with the fuel you are running!! Plus tightening up the LSA on the cam will make it more responsive too! What rocker ratio are you running??
If it were me, id wash the block down, hone it and put it back together with the new parts! Check the balance of the rotating assembly if you are changing pistons. With a proper tune, i dont think you will have a problem going mid to low 6’s in the 1/8 now!
 
dadodgekid said:
Going up in compression will be killer with the fuel you are running!! Plus tightening up the LSA on the cam will make it more responsive too! What rocker ratio are you running??
If it were me, id wash the block down, hone it and put it back together with the new parts! Check the balance of the rotating assembly if you are changing pistons. With a proper tune, i dont think you will have a problem going mid to low 6’s in the 1/8 now!
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Maybe in Seattle but not his home track. I don’t think he will pick up a second in the 1/8 mile with this those upgrades. That car was missing some ET with his last combo and without hearing what he is running for a convertor I’m betting his stall is to low. If I were a betting man I guess 4000-4500 stall in his last combo.
 
pittsburghracer said:
Maybe in Seattle but not his home track. I don’t think he will pick up a second in the 1/8 mile with this those upgrades. That car was missing some ET with his last combo and without hearing what he is running for a convertor I’m betting his stall is to low. If I were a betting man I guess 4000-4500 stall in his last combo.
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You are pretty close IIRC. I think (again, this is ME thinking and we all know how that goes) the OP mentioned in another thread he had a 3500 converter.

That’s low for a street driver. I just ordered a PTC converter for a friend. It ended up being an 8 inch housing and an 8 inch stator. That should be close to 5000-5200 RPM flash stall.

And that’s what we came up with for 70% street/30% strip use. They use this in a lot of dragweek stuff. If the cam is right ( a Racer Brown spec’d solid roller) and if the idiot doing the carbs doesn’t have his head right directly up his arse, this thing should be very impressive.

I’m hoping this thing hurts some people’s feelings, because the way it was, was completely depressing.

And my point is...today a converter like that is as driveable as a 3500 converter was 30 years go. A good converter company, just like a good cam grinder, is a hot rodder’s best friend. Way to many guys just don’t have enough converter. Not saying the OP doesn’t, just making a general statement. Today’s converters do way more than 30 or even 20 years ago.
 
I just switched to Rons flying toilet. Obviously you know what your doing with no moisture in oil. I’ve read a lot of horror stories about methanol getting into the oil.

Hopefully it warms up today as I want to fire it up for the first time on methanol

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Between having a Stroker, being on alcohol, and especially a toilet, when he gets the right converter in it he can rotate the earth.
 
79410aspenrt said:
I just switched to Rons flying toilet. Obviously you know what your doing with no moisture in oil. I’ve read a lot of horror stories about methanol getting into the oil.

Hopefully it warms up today as I want to fire it up for the first time on methanol

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Most of the oil getting alcohol in it is because guys like to run them really fat at idle. They use a cooling system way too small because they think alcohol will cool the engine. It will, when you run it pig rich. To make power you have to make heat. I never used alcohol to cool my stuff.

The other issue with alcohol in the crank case is oil. You can’t use Group IV or V synthetic oils and alcohol. You’ll never keep the oil clean. Group III oils only. Unless you spend 14 bucks a quart (which I did gladly) to get a synthetic blend that uses Group IV and V base stocks. Then you can do it, but very few companies make an oil like that.

I forget what percentage of leak I set my Ron’s barrel valve at, but the last I remember or a barrel valve I made, with a 15 pound idle check, I was able to leak the barrel valve at about 16% and still get a good idle.

Get the idle cleaned up, and you shouldn’t have alcohol in the oil. Also, I never ever lean the engine out with the fuel shut off to warm it up. Ever. If you need to do that, you need to fix the idle stuff...smaller nozzles...higher pressure and less barrel valve leak. I’ve seen guys hurt the engine on warm up, not know it and make a run and kill it.
 
i have the primer plus plate system to warm up and run in the pits on gas. supposed to be for easy starting and to build some heat into engine as well. i'm new to this methanol system so i'm sure there is some learning to do.
 
I've been thinking leaving the compression down low and just injecting some artificial air because of the elevation...
 
Home track ? Have you ever ran at Spokane or Walla walla
 
fishmens67 said:
Home track ? Have you ever ran at Spokane or Walla walla
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I’ve raced at Spokane many time. I first raced there in 1998 when it was still AHRA. Last time I was there was for the Division 6 finals in 2015?

I have a Coan 8” spragless, 4800 stall. 1.5 rockers for now. 1.6 would be nice, but probably not happening this year. I use an AEM wideband for tuning, so AFR is always good. Timing has been set at 35*. Our corrected altitude is always about 7000’ at home which is a battle. Also use an old nitrous plate as a primer for starting on gas. At the end of each day I bring the engine temp too 200*, pull the breathers and let the moisture evaporate. Spray the intake with WD40 then crank it over before parking the car after the weekend. Never water in the oil.
 
It kinda sounds like you are moving away from street driving. If so it would love a 5600 stall converter.
 
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