74 620 V8 Swap

[mccuistion]

Could you post the size and offset of your wheels? i really like the fitment and would like to copy that offset. Have you done your front disc brake install yet? i'm also wondering if they will clear discs or not, i plan on doing Z32 brakes.

[Stoffregen Motorsports]

Yeah, what's up with this truck? Been too long without updates.

[*fart*]

Been a while!  Managed to get the truck up and running and road worthy last week...  Shop has been busy, so time to work on it has been limited.   Still have a ton of work to do, but its been awesome putting some shakedown miles on it and figuring out next steps.  Got the alternator mounted and a few gauges mounted in the dashboard..  Still have a couple more to fit in somehwere... Basically wired a fusebox and harness for the engine controls, then cut the whole stock wiring harness down to just the lighting system.  So all the lighting system and a few accessories works off the stock fuse box and harness.... 

 

Today i spent an hour or two and sound deadened as much of the cab as i could.... Next i have to seal up shifter hole in the floor and a few firewall holes... Then i can get started on some carpet for it!

 

Ill have to try and get a few more videos of it running soon... 

 

 

 

 

 

 

 

[]2eDeYe]

Tough looking little guy. :)

 

[Stoffregen Motorsports]

I like the hood scoop. Barely peeking above the hood line, and classic to match the rest of the truck.

[banzai510(hainz)]

those headers look like they will be a proplem later but looks clean build

[datzenmike]

1 hour ago, Stoffregen Motorsports said:

I like the hood scoop. Barely peeking above the hood line, and classic to match the rest of the truck.

 

 

Reverse scoop for the win. Keeps rain and crap out.

[Stoffregen Motorsports]

I wonder how you spell ram air in Japanese.

[]2eDeYe]

Google translate FTW
lol

ラムエアー

Ramueā

[*fart*]

Tried to keep the hood scoop low key.  Im gonna make a leather stitched cover for the back 2/3 of the scoop... then ill have some attachment points so i can put a rain cover on it... 

 

Not sure what you mean about having problems with the headers later... other than heat!  lol... I still have a good amount of heat shielding to make, and will probably end up at least partially wrapping the headers/downpipes...   Also the entire exhaust system is just kind of made to get by for now.  I hate how low it has to hang, but it is 3" dual.  

 

Winter is coming here so im just trying to do as many shakedown miles as i can before i pull some stuff apart for the winter.  Biggest project for the winter will be swapping the rear end and getting another custom driveshaft made.  Will probably reinforce the frame in the rear end a little bit.  Maybe research a homemade ladder/4 link setup.

 

Then once the rearend is done ill focus more on the motor.  Goal is to make 400-500 hp range... on the tightest budget i can... lol... 

 

And of course there are a million other little things to do... Need to freshen up the front end a little... back when i was driving this truck 5 years ago i had a laundry list of stuff to do before it was stolen... pretty sure i have a front wheel bearing on its way out...  but i think i have it in my stash somewhere.. 

[distributorguy]

A set of cheap Ebay heads professionally ported (since it looks like you already have a Vortec engine?) with a good solid roller cam and the right carb, that should put you solidly into the 400's, but at a price tag of around $3000.  The decent cam/lifter kit is $1250+.   You can save $ by only having half the driveshaft custom built, but a full length aluminum version might be a good idea.  

The Ebay heads generally just need around 10% more flow on the exhaust side - too restrictive.  DIY porting and you're in for under $700 for new and improved heads that flow well over 300 cfm.    

 

Skip the ladder bars and have a custom set of main leaf springs made with a higher spring rate (thicker).  That'll prevent wheel hop and axle wrap, as well as eliminate a couple other leafs to reduce weight.  Stack the lower springs further forward to also aid in reducing wrap.  You can pick your ride height at that point - with reverse spring eyes and no lowering blocks.  Measure your center-to-center distance you want and the main spring will end up a bit shorter than stock.  

Edited October 24, 2019 by distributorguy
clarify

[Stoffregen Motorsports]

On 10/18/2019 at 8:20 AM, *fart* said:

 

Not sure what you mean about having problems with the headers later... other than heat!  lol... I still have a good amount of heat shielding to make, and will probably end up at least partially wrapping the headers/downpipes...   Also the entire exhaust system is just kind of made to get by for now.  I hate how low it has to hang, but it is 3" dual.  

What I notice is the lack of any heat shields around things like the master cylinder, etc. Building nice heat shields takes time though. Use the peel and stick aluminum heat barrier on the heat shields for extra protection.

[*fart*]

Heat shields are going to be top priority this winter.  I still have to make a restrictor plate for where the thermostat goes.  Since im running an electric pump i cant use a normal thermostat, but most people recommend just a steel plate with holes drilled to slow down the water flow so more heat exchange can take place.

 

As far as the drivetrain goes, the motor has more than enough power now to spin one rear wheel almost whenever i want...Right now i just have some shitty swirl port heads on the motor.  I was searching locally and craigslist and came across a couple sets of used Edlebrock aluminum heads for around 350-500.  Now these would still have to go to a machine shop but they are out there.  Cam and rocker choice will prob be dictated by the heads once i find a set.  There are also a couple race car swap meets around here at some of the local circle tracks... Im hoping i can shop around and score a good carb and intake for reasonable amount.  

 

The rear end is going to be the next major project.  Right now im still looking at the Ford 8.8 Explorer rear end with lsd, but ive been looking into some ford 9" rear ends too.  Thats going to be this winters work.  im def gonna look into getting some custom springs made.  Right now i can almost feel the axle wrap you are talking about.  I have 2" lowering blocks on the back and im sure my spring bushings are pretty rotted.  But once the truck starts hooking up its going to be a problem.  

[datzenmike]

What???? Just run the regular thermostat. You have to run a thermostat.

 

What restricter plate?????  News flash, faster flow gives better heat transfer. Anyone that thinks slowing coolant flow in the rad makes it give up more heat is totally wrong headed. Heat transfer is always fastest when there is a larger differential between hot and cold objects. Imagine an orange glowing hot horseshoe and how fast it cools from 1700-1900F down to not glowing at all, a drop of about 1000 F. Probably a minute? Likely less. Now imagine how long it takes a cup of hot coffee with even less mass to drop from 200F to room temperature. A drop of only 130 degrees. Hours maybe more because as it gets closer to room temperature there is less bias.  Not convinced? Have you ever seen buildings heated with a boiler and hot water radiators? How do you make the room warmer??? You turn the hot water flow through the radiator up. More hot water = more heat transfer into the room. Too hot? you turn the flow down.

 

Starting coffee temperature 200 degrees (F).

Cooling down from 200 degrees to 150 degrees (50 degree drop) took 14 minutes.

Cooling down from 150 degrees to 100 degrees (50 degree drop) took 45 minutes.

Cooling down from 100 degrees to 75 degrees (25 degree drop) took 2 hours.

Cooling down from 75 degrees to 72.4 degrees (2.6 degree drop) took 1 hour....... http://www.wisedan.com/coffee.html

 

Does your truck run cooler in the summer when it's 100F out or cooler in the winter when it's -10F????? Bigger temperature differential = more heat transfer.

 

You want the hot water out of the engine as fast as possible and into the heat exchanger. The hotter the entire rad is, the more heat will be shed.

 

 

[*fart*]

You cant run a regular thermostat with an electric waterpump with no bypass.   When the thermo shuts the electric pump will build up pressure and burn out... Where as a stock pump has a bypass route.  This was blocked off on my application... 

 

I think if i ran an external bypass i could run a stock thermo... As far as the restrictor plate it was just what i was reading at the time..   After reading more it looks like you are right.. most flow is the best!  I just gotta get another fan!  

 

 

[datzenmike]

The pump isn't hydraulic it's basically a propeller with lots of slip. Fans don't burn out if you block the air flow.

 

Engines are designed to work near boiling point for best efficiency. Engines need to warm up as fast as possible and be kept there accurately. Having no thermostat it will never get to operating temperature and will be up and down depending on outside temperatures and how hard you are driving it. You need a thermostat to regulate the engine's temperature.

[Stoffregen Motorsports]

Out here in the warm west, using a thermostat with the plunger removed is common on old tech high performance engines. Basically just take a thermostat and cut the two legs that hold in the plunger and you now have a restrictor plate. Not ideal, but it does slow down the coolant giving it time to do its job.

 

I have no experience with electric water pumps, so I can't argue either way on that.

[*fart*]

Yeah thats basically what i was thinking when saying restrictor plate..  Ive read that at idle and city driving water moving slower through the rad will have longer time for air from the fan to pass through and cool.  Just like the stock rpm reliant pump would do in traffic.  But then at higher rpms the water flow on the electric would be too restricted to cool the car at freeway speeds... 

 

Right now the only cooling problem i have is too small of a fan.  Once i upgrade fans and fine tune the cooling system a little bit i should be fine.  I have the system separated by toggle switches so i can easily start the engine and let it warm up before i even kick the water pump or fans on.  An electronic controller might be worth looking into as i could automatically kick on the main or aux fans at different temperatures and only work the water pump  above a certain temp... 

 

 

[datzenmike]

26 minutes ago, *fart* said:

Yeah thats basically what i was thinking when saying restrictor plate..  Ive read that at idle and city driving water moving slower through the rad will have longer time for air from the fan to pass through and cool. 

 

 

 

The premise is faulty. If it were true you could make the hole the size of your little finger and really cool the engine down. Obviously that won't work. While the slow water in the rad is cooling longer the slow water in the engine is getting hotter too. Heat transfer is always faster when there is a larger temperature difference. Fill the rad with the hottest water as soon as you can.

 

 

Fans.... human error, remove yourself from the equation. You want fool proof. Get temp sensors in the rad return line that control relays to turn the fan(s) on/off. I know of no car maker that has electric fans that the operator turns on and off. It's enough work driving let alone watching the temp gauge and flipping switches on and off, or forgetting to. What if in an emergency someone has to drive your car?? Will they know what to do and remember?? Mine are automatic and even work for heat soak after I turn off the ignition, shut down and get out of the car. 

[*fart*]

No offense man but im basically agreeing with what you are saying.  How is the premise faulty that a stock water pump doesnt pump as much volume  at idle as it does at high rpm?  The water flow is slowed down and the heat generated by the engine is slowed down as its at idle and not under load.  

 

As far as the fan switches im going to do whatever i want with my truck.  The truck was stolen out of my driveway which is why i had to swap the motor.  The LAST thing that I will let happen is someone else drive my truck.  

 

This whole thread you have been chiming in with negativity.  Im all for constructive criticism but you can take you lectures and leave them somewhere else....

 

Thanks

[datzenmike]

I was referring to the restriction slowing the water flow through the rad to give it more time to cool. On the face of it, it seems kind of sensible. But this is the wrong premise, that's all.

 

Next time someone steals your truck, will they know how to work the manual on/off switches for the fans???????? The cooling system has to work by itself to be fool proof! Surely you can see this???

 

At the risk of seeming even more negative... it's only negative because right now you may disagree or you haven't thought it through. Think about it and the light will come on. 

 

 

[*fart*]

Im over it man.  I dont even understand what you are accusing me of disagreeing about LoL.  

 

I was just wondering if a restrictor plate would help shed some degrees.  It looks like it wont help so im not going to do it.  Lol.  

 

As far as whether you think I cant remember to turn on the fan when the temp gauge gets too hot, ill chalk that up to the fact that you dont know me.  

[datzenmike]

Not accusing just pointing out some things. I'm sure you can read a temp gauge and flip a switch, all I'm saying is it's unnecessary involvement. There's no sense making it complicated and more work. Like I said I don't know of any car maker that does it this way. Electric fans should be at least the same as belt driven in their ease of use.

[Stoffregen Motorsports]

It is not a false premise Mike. Restrictor plates are built in to all thermostats. They are generally metered so that the coolant flow does not exceed the ability to cool it.

 

Most race cars do not run fans, for obvious reasons, and as a safety measure against a sticking thermostat, the thermostats are removed. We all know that you can't just remove a thermostat though, and engine builders/tuners know this too, which is why they all use some form of restrictor plate.

 

I know, I can hear you crying "race car, race car..." but the premise is the same whether you are running flat out or idling in traffic. A properly sized orofice in which the coolant passes will meter the coolant flow so as to allow enough time in the radiator for the coolant to cool down.

 

You are right about how it alters an engine's ability to warm up, and this is a concern when you remove a thermostat, but having an electric fan in lieu of an engine driven fan is one way to combat this problem. Truckers often block off a portion of their radiator with cardboard to reduce airflow. There are ways around the problem of too much cooling.

[datzenmike]

I'll agree with anything you say except 'slowing down the coolant so it has time to cool in the rad' is totally... wrong. Back to my previous statement about houses or apartments warmed with boilers and radiators. If you want more heat you turn the flow UP, not restrict it. Heat transfers from hotter to cooler and the bigger the difference the faster the change. I don't know who first thought this myth up about slowing the flow down to cool but I think everyone just went with it simply because it sounds good and perpetuated it. The faster the flow the hotter the rad. The hotter the rad, the more heat it will shed.