Estimate my 347's HP

[thekid760]

My engine setup:
347 kit w/ 5.4 rods, cast steel crank, and Speed Pro hyperutectic pistons.
1978 302 non roller block bored .030 over and clearanced for crank
Stock 78 heads rebuild, and mildly ported by me
1.6 roller rockers
RPM air gap intake
Holly 650 DP carb with mechanical secondaries
Isky solid mech cam Part#: 381358 278 adv duration 244 @.050 .512 lift 108 degree centerline
Hi volume oil pump
stock pan
1 5/8 long tube ceramic coated headers
MSD pro billet distributor
6al ignition box


What would you estimate my setup would make?
This will eventually be paired to an AOD w/ 3000rpm stall and 3.73 rear gears.

Any comments or suggestions?

 

[Sevan]

somewhere around 350 (+/-) at the crank, this is just a guesstimate...get it dyno'd when ur ready then ull know....good luck

 

[Wallzy]

Why is it that we play this guessing game? There are so many other factors than what you listed. It seems like everyweek someone is asking, "How much power will this make" or "What will my car run if i have this." Don't use the search engine and read? Every question that i have ever needed has been asked about 5x on this forum and out on the internet. Sorry for venting.

 

[86bluecobra]

I'm not going to guess on your power but I will tell you that IMO the heads have got to go. Those will choke your 347 stroker. I do not think with those heads you will see 300+ hp.

 

[BK_CAULEY]

1 million H.P.

 

[86bluecobra]

1 million H.P.

thats funny right there I don't care who you are thats funny right there.

 

[twistedwankel]

http://www.wallaceracing.com/Calculators.htm

Put it together and run the numbers against these calculators.

Then you will know what you have at your wheels.

Otherwise buy a shelf motor that they have all ready tested and will guarantee.

The answer to your question is: Zero HP as it will never run.

 

[tkareno]

350 mayb more

 

[68keyblr]

If you are on a budget, why not get a set of GT-40s or GT-40p's and have them ported? Those '78 heads were designed around fuel economy and low emissions, not performance.

 

[85ragtop]

How much HP not tech.
Moved to talk.

 

[$uperstang]

300RWHP 340rwtq is my guess

 

[thekid760]

Why is it that we play this guessing game? There are so many other factors than what you listed. It seems like everyweek someone is asking, "How much power will this make" or "What will my car run if i have this." Don't use the search engine and read? Every question that i have ever needed has been asked about 5x on this forum and out on the internet. Sorry for venting.

I understand where you are coming from, but keep in mind that every engine setup is different, thats why I was not only requesting the guesstimated HP, but also any comments or suggestions pertaining to my setup.

If you are on a budget, why not get a set of GT-40s or GT-40p's and have them ported? Those '78 heads were designed around fuel economy and low emissions, not performance.

Thanks for the advice, thats what i'm looking for. How much should I expect to pay for for a ported set?
Whats the difference between the GT-40's and the GT-40P's?

I was thinking about just using this setup for now and when I save up enough money, I'll replace then with some AFR 185cc's.



I ran this engine setup through Engine analyzer Pro using stock heads w/ 10cfm more airflow throughout the lift range.

348hp@5250rpm & 370tq@4250rpm
View attachment 369625

That sounds about right from what you all were guessing.


Other than the heads (which I know is a huge restriction) is there anything else that you can see problems with in my combination?

By the way, I was told with the current piston/head combo I should have around 10.7:1 CR.

 

[Turkey Sammich]

It would be easier just to dyno it and put the guessing game to the side. If anything I would make a thread asking what I could do with my current set up to get more out of it or what mods I could do to see better performance.

So, with that said. I'm guessing 97hp 78tq.

 

[68keyblr]

Thanks for the advice, thats what i'm looking for. How much should I expect to pay for for a ported set?
Whats the difference between the GT-40's and the GT-40P's?

I was thinking about just using this setup for now and when I save up enough money, I'll replace then with some AFR 185cc's.

I got a very nice set of ported GT-40's with FRPP 1.6 roller rockers on ebay for about $600.

You should be able to get bare 40's or 40P's for $200-$300. Or, just go to the local pick and pull and find a 98-00 Explorer (I believe that's right, double check though) for a set of 40P's.

GT-40Ps flow better than GT-40s but have a spark plug angle that limits your header choices. Either set with a good port job can scream.

 

[niklid05]

260 to the LF and RR.

 

[thekid760]

260 to the LF and RR.

That might be fun doing donuts with

But seriously guys, I know it's near impossible to predict horsepower for a given combination considering all variables, if that were the case then we wouldn't need dyno's.

I think I'm more asking if anyone can see any major flaws in my combination, and if so would you mind providing me with some positive criticism.

I know the heads are my bottleneck right now, but those will be addressed in the future, so for now they'll have to do, not enough $$ in the budget for them.