Betting and guessing and all that leads to odds that are probably not in his favor!! Do you understand torque convertors? A hot rod street situation is very far from what a four wheel drive needs as far as performance is concerned. Sure a wound out motor may sound good, But it is not making use of the true potential of the motor unless it is designed for high rpms!! The 351 stock is definately not a high rpm motor! Nor should it be unless the heads are changed out as well as other components! The sooner you can have 80% or more lock up in the torque powerband the more satisfied you will be with the 351 performance! Find a spec sheet on the motor you used and go from that but disregard all the road car stuff you find that leans towards horsepower you want torque in any motor that will spend time off road! Horsepower is figured from torque, You multiply the torque rating by the rpms then divide that figure by 5252. Horsepower is only half the potential of the motor biasing component choice on horsepower alone will be a let down off road. The real WOW feeling comes from torque, increasing that will make the most difference in how the vehicle feels behind the wheel especially off road, even when you are on the road with bigger tires, lift, extra weight and too tall (numerically lower) gearing you will increase the overall felt performance by going with a matched torque convertor. You should look for a sub 2200 rpm lock up in the biggest diameter you can get for the greatest off road performance and road economy(mpg) The reason you chirped the tires is because the motor was overrevving then when it did lock up, it was probably up in the 3-4000 rpm range way too high for the 351 to live a long happy life! What made you change out the motor by the way?
he wont even notice the difference....it's a stock converter....the torque difference in the two is not enough to make that converter heat up.....and even if it does stall a little higher it would only be 100rpm maybe
Yes I understand torque converters. They multiply torque. The more torque that you have the more it will multiply and stall a little higher.
When I had my Camaro, yes I strayed once, with a 388 stroker, 3800rpm stall with 6.14 gears, the converter didn't stall but to around 3000rpm due to the 6.14 gearing. When I dropped back to 4.56 gears, it stalled to 3800rpm. Stall speed has many variations, torque output, gearing and vehicle weight.
Even if you look at aftermarket converters, they have a range, such as 2800 to 3200 depending on variables I just mentioned. With just an engine change, 100 to 200 rpm is about the most of a difference that you will see.
Personally, I think the 80's model stock converters are too tight. The 84 351W that I have in my 63 F100 throws gravel as soon as you touch the gas because the stall speed is too low.
I've been building vehicles and engines for about 25 years and I have learned a thing or two along the way.
i don't realy understand torque converters the old 302 was burning oil bad and also didn't run that well. I though the tranny shifted at a higher rpm because of a shift kit not allowing the tranny to shift to the next gear until a higher rpm and then it shifts pretty fast. maybe somepne should explain what stall is I have noticed differnt vehicles that i thought had a bad stall torque converter that the vehicle didn't mov until the engine reached a higher rpm I thought that was stupid.
When you have a large camshaft the doesn't really make power until you get up in the rpms like say 3000 rpm, then you would want one that doesn't lock up until around 2800 or so to get the engine into the powerband. It will still take off normally, just with more slippage until you reach the stall speed.
You need to brake check the stall as it is and get back at what rpm's the converter is hooking up andy! So Lx The stall speed is also affected by traction less traction equals lower stall speed, So the action of throwing gravel is not any indication of being too low. Brake check yours and let us know what it stalls at! Most people are running around with too high stall and thats why you see a lot of 4x4's toasting transmissions, breaking driveshafts,etc. Reading Hot rod/strip tech about convertor selection will send you down the wrong road for off road! You shouldn't be just telling him run it! Is what I am getting at, I am asking for numbers to send him the right way if need be.
Sorry Blue Beast but Andy asked about stall converters and i found that artical. might not be the best but it was what I found doing a goggle search, maybe you should do one for him.
Again I am hearing stuff about braking parts with a higher stall converters, that is a bunch of bull. If anything it has a softer shift until you are up over the stall...so how does a high stall converter brake parts. And once you are over the stall say 3500 whats the difference in how hard it shifts..the converter is locked. I have run many high stall converters in my day and have never broke a thing. I have swaped 302s for 351s and 300s for 302s and have used the same stock converter with no problems at all. I even pulled a 260 from a 64 Farlain and put a 302 in it... same converter, no problems............and if your cooking transmissions with a higher stall converter you might want to install a bigger cooler, thats what I do.........
he asked why the converter would not fit his 351 and I answered it......Why are you turning this into a meetings of the minds
and by the way how many engines have you swapped out, had you ever swapped out a 302 for a 351W and used the same converter you would say RUN IT......
if you want check my video in my sig of my truck it's got a 2000 stall converter in it. check how hard it goes into gear from park on the third pull... High stall converters don't free wheel the engine until it hits the given stall slamming the drive line, it will move the truck car just like a stock one off idle it just feels loose.
If you are stuck in deep sand say and you try to power out with a high stall when it does go 1:1 all those rpms go right into the driveline. It would be like revving a manual up to 3500 in the same situation and dumping the clutch, If the wheels are stuck you are going to break something!! Andy can do his own searches and pool up all the info he finds and make his own choice. He did ask for an explanation of stall speed and TC differences and I asked him for the numbers he gets from a simple test to maybe give him an idea what he has now and what to look into for better performance. Putting a bandaid on a problem (larger cooler) might work for on the road where you will have better air flow over the cooler, But if you spend time off road then having the biggest cooler in the world isn't going to help on account of slow trail speeds and mud clogging the fins! And those same slow speeds will leave the TC generating heat if it is not 1:1 Any time the input and the output are spinning at different speeds you are generating heat!!(cut that time down=reducing heat and heat related wear) Anybody can say they have changed this swapped this and no one will know if it's the truth or not.(so I am not getting in that pi$$ing contest, This is the internet the world of make believe) I don't really care if anybody changes thier minds or swaps to a different part, I am trying to help out a fellow off roader get the most out of his vehicle! He can take it or leave it! I have changed out to lower stall for off road and the traction and power delivery difference is definately worth it. Most people drive off road the wrong way anyhow, They always try to power out with too much throttle. So a tc swap for those folks is not going to be readily used to it's potential. For what it is worth I drive off road for a living so I spend alot of time and research figuring out how to perform my job better and extend the life of my vehicle(either work truck or my personal truck)
it's a stock converter how high do you think it will stall?
and if it takes X amount of torque to move the tires when your stuck what does it matter what's turning them? At least if you have the converter matched to the engines torque curve you might have a chance to turn them in stead of sitting in the hole bogged down.
and most off road trucks should have electric fans cooling them because of that reason, the last thing you want is the stock fan blowing water and mud all over the engine..
# 1 Exactly it is a stock one on a modified vehicle (bigger tires,gearing,shift kit and a bigger motor) I do not want to guess that's why I want him to brake test it!!! #2 and if it takes X amount of torque to move the tires when your stuck what does it matter what's turning them? At least if you have the converter matched to the engines torque curve you might have a chance to turn them in stead of sitting in the hole bogged down
I think your agreeing here with me A matched converter is what I am trying to set andy up with!! #3 What? Where I live you can't afford to have an electric go out and be 30 miles out in deep sugar sand or mud, Maybe an auxillary one yes but a lonely electric NO WAY maybe for a trailer queen!! I don't know about you but I will put my truck into water/mud over the valve covers and not have a care about getting my motor dirty!
Thanks for the info, I got a lot more than i bargained for. I never wouild have thought a torque converter would make that much difference. I will do the brake test thing and let you know. I should be wrenching right now instead of typing.