Novak Conversions Jeep Wrangler TJ radiator

Edelbrock head results

LJ-Jeff

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Oct 1, 2018
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8
Location
Coquitlam BC
I was having issues with power and overheating while towing my Patriot trailer, so working with my shop, decided to put in the Edelbrock head, new cam, headers and new radiator. While we were in there, we port matched and polished, and did some clean up. Haven't hooked up the trailer yet, but very happy with the results after tuning. Just wish I had dyno'ed before the mods were started to see the full gain.



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Nice, any worries about the header cracking? I've been told by some local shop owners that most 4L headers end up cracking but I'm always interested to know if someone has solved it.


There must have been a time
when we could have said no.
 
Thanks so much for sharing this! I’ve been wanting to see actual numbers on this for a while.

I can tell you with certainty that at sea level, the 4.0 puts down around 150hp at the wheels. It will put down even less at higher altitudes.

Do you know what altitude you’re at?

Either way, you gained a considerable amount of horsepower. I’ll bet the engine feels very alive, huh?
 
Nice, any worries about the header cracking? I've been told by some local shop owners that most 4L headers end up cracking but I'm always interested to know if someone has solved it.


There must have been a time
when we could have said no.
Thanks so much for sharing this! I’ve been wanting to see actual numbers on this for a while.

I can tell you with certainty that at sea level, the 4.0 puts down around 150hp at the wheels. It will put down even less at higher altitudes.

Do you know what altitude you’re at?

Either way, you gained a considerable amount of horsepower. I’ll bet the engine feels very alive, huh?
I haven't had a chance to really get it out, going for a good drive tonight to see what she can do!
 
Nice, any worries about the header cracking? I've been told by some local shop owners that most 4L headers end up cracking but I'm always interested to know if someone has solved it.


There must have been a time
when we could have said no.
We used a thick, race style gasket to try to eliminate heat transfer, hoping that helps. Let you know if it works!
 
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Yes, I've talked with a number of 4.0 engine builders and they all agree that 150whp is about what they put down stock.

So that means you gained a pretty darn good amount of wheel horsepower!
 
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Nice to see the dyno sheet . . .
Looking at that nice 'fat' torque curve.
That's the 'seat of the pants' gain.
Has that shop in Maple Ridge done a few of these 4.0L motors?
What cam did you use ?

The shop hasn't done many 4.0's, but have lots of tuning experience, we used the Howards cam, 320111-12. Have to say after taking it for a good drive yesterday, the torque gain is sure nice on the hills, few little gremlins to work out, but all good.
 
The shop hasn't done many 4.0's, but have lots of tuning experience, we used the Howards cam, 320111-12. Have to say after taking it for a good drive yesterday, the torque gain is sure nice on the hills, few little gremlins to work out, but all good.
Have done more than a few dyno runs at PDR in Langley . . . .
Interesting thread . . . thanks for posting.
 
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What cam? Did you swap injectors? Oversize throttle body? What intake manifold? I am eager for more information.


We didn't do the injectors or throttle body, left the stock manifold. It was just the Edelbrock head, polishing, headers cam and a tune. Pretty happy with the results

https://www.howardscams.com/hydraul...06-american-motors-40l-1000-4400-howards-cams
Glad I did it too, the oil pump drive had failed. Wasn't one of the ones covered in the recall, but would have caused issues soon!
 
About to order this head, did you upgrade the cam and rockers? H20 Pump? What did you go with? Did you do anything with the injectors or the intake ports? Summit has been great with help and questions but did say you will want the Superchip reprogrammed with this head by a pro, what did you find?
 
The Edelbrock head alone will not net much since it's only a few cc's smaller combustion chamber than stock, the valves are the same size, and the ports are roughly the same dimentions. It does have an improved combustion chamber shape, springs can handle a little more cam lift than stock, and being made of aluminum will draw heat out of the cylinders faster so it can stay out of detonation. These things help when you put in a larger cam or increase the compression ratio. One other benefit is you can fish the lifters out without removing the head, but it's still a tricky game with long reach magnets.
 
In researching this I’ve found a bit of info regarding this head switch and net gain in HP and Torque can be relatively small if that’s all your after. What I’ve found is a few really unhappy campers sort of hoping this would be a magic bullet. I plan to use this to beef up my top end in conjunction with adding a turbo and so with a torquey cam and ARP bolts etc. I’m thinking it’ll help the engine handle and make better use of the added boost from the turbo 🤞keeping my fingers crossed
 
Novak Conversions Jeep Wrangler TJ radiator