Horsepower guestimate

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bighammer

bighammer

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I'm curious about horsepower. I'm an absolute novice in regards to this. Seems like 300 horsepower is fairly easy to obtain with a small block 360, by just bolt ons like intake, carb, headers, etc..

But I am curious about my setup. I don't even know what stock horsepower is on a late model LA 360 with roller cam. All I am planning is to replace the TBI with Weiand action plus intake, 600 cfm carb, HP manifolds, and 2 1/2 inch dual exhaust. Will I make 300HP with stock cam and heads?

Thanks
Mark
 
Yea you will be right around there. I had a custom cut cam for my 360 roller which is an 89 -91 block so it had the good heads. I ported and polished the heads with a single plane intake put bigger valves in the head and 10.5-1 pistons, dynoed at 430hp. For a few extra bucks you can make some real good power.
 
Not to be a buzz kill Mark, but I'd be happy with a true 250hp. The stock cam is really your enemy with that combo in my opinion. After saying that, it should be a great running engine. Very peppy and stock drivability. :thumleft:
 
I don't know if anyone can predict that without more info.


Compression, cam?


You should be able to come close to one HP/Cubic inch if it's done right.


Here's some shots of a 91 360 that my oldest son and I are building. 9.2 compression, Hughes 219/228 cam, ported heads, LD340, Holley 600 CFM Vacuum Secondary carb, and 70 340 exhaust manifolds. It's going into a 71 Valiant 4 door.

View attachment Ken 360 E04 B.jpg

View attachment Ken 360 E09 B.jpg

View attachment Ken 360 E07 B.jpg

View attachment Ken 360 E13 B.jpg

View attachment Ken 360 E02 B.jpg

View attachment Ken 360 E15 B.jpg
 
Prob not with stock cam..I got the same set-up in a 4x4 ramchgr,last yr for the carb,88 model 360,eddy 650, perf intake, 2.5 exh,guessing 250-260hp...it will pull anything,good torque,if I keep it I will install a stock 340 type cam and re-do the 308 heads on it,maybe headers,will def get rid of the eddy carb,I do not like them as far as perf or mpg,will go carter avs or thermoquad,it came factory with a quadrajet for real...had way more power and got 17 on hwy..now 10mpg all around and down on power...
 
Love them Ld-340 intakes...one of the best ones all around,hard to beat...
 
OldmanRick said:
That's a nice build Karl, but if Mark is only going as far as the above...?
Click to expand...

Well, I would like to do more, but$$. Anyway, the engine is truly a low mile (under 30k) reman. I think in addition to the above, I would also like to replace the cam and have some head work done. Any ideas what it would cost to have the heads reworked for 2.02 intakes?
 
I wouldn't worry about the heads Mark for what you're looking to do. Those engines have a realistic net rating around 180/190 hp. I gave you 60 or so with the int/carb/decent exhaust. The real weakness is the stock cam. I'd look for a custom grind...maybe from Bullet, etc? that will work with your current thoughts on the other bolt on's. I can see getting really close to that 300hp area with the proper grind that works with your current compression, torque converter, gearing, etc.
 
I just took my car to a dyno two nights ago

remanufactured 360 with stock heads, stock bottom end.. I added a Comp Cam XE268H cam kit, Edelbrock Performer intake, Performer 600cfm intake, headers, 2.5" exhaust.. we still need to do some more tuning on the carb.. but we ended up getting 218hp at the wheels, 286 torque .. yes.. there's still more there.. but I have a whole different understanding of wheel horsepower now!
 
Call Ken at oregon cam grinding. He reground my roller cam for 150 bucks. It sounds real nasty but that's the way I wanted it. The stock cam is tiny and really holds that motor back.
 
bighammer said:
Well, I would like to do more, but$$. Anyway, the engine is truly a low mile (under 30k) reman. I think in addition to the above, I would also like to replace the cam and have some head work done. Any ideas what it would cost to have the heads reworked for 2.02 intakes?
Click to expand...


Yes, he should upgrade the cam.


If you decide to run Hughes, beware. There are two cams for the "magnum" engines. One is for mechanical fuel pumps and has a longer nose for the mechanical fuel pump eccentric, and the other is for electric fuel pumps and has a shorter nose. :banghead:

I told Hughes that I needed the cam for the mechanical fuel pump. They decided to send me the one for the electric fuel pump without the nose (same price for both cams). Then included the BS rigged up "Nose extention" for the cam to adapt it for the mechanical fuel pump for an extra $30 without even consulting me. They said that it was the only one that they had in stock. I would have rather waited for the proper cam, I do not like how they designed the nose extention and made a few improvements myself and hope it works. How nice of them to send me the more expensive f*cked up pieces instead of THE PROPER ONE.

But from what I hear, their grinds are pretty good. I just don't like the way they make decisions for me without consulting me that affect the quality and outcome of my engine.... :finga:
 
Perhaps they've fixed the cam snout extension since I ordered mine a couple years ago, but I had to have .100" machined off the "cup" washer so the pieces would seat properly...that was part of the instructions, but I fail to see how they sell the damned thing for that purpose, but oblige the buyer to spend another $30 on machine work to use a part that's already $35...sore spot with me when I converted my Scamp to a 5.2 Magnum...but, when it's fitted properly, it does work.
 
I don't know if anyone has said this yet but why not use headers instead of a manifold? If your looking for 300 at the wheels then getting the heads reworked might be needed. I know a lot of guys who have pulled 300 from stock heads but it requires a bit of time tuning and the perfect cam. My question is will you really be satisfied with 300? If it was my motor I would keep it out until I had the money to do pistons and heads. We all will pull our motors a few times but i always try to go one step ahead of what I want that way I will be satisfied a little bit longer.
 
I may be wrong here but I seems to remember about a 20% loss is average. So around 360 at the crank. I'm sure someone knows more than me and will chime in.
 
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