How many HP is my 340 pushing?

[RUNCHARGER]

Raptor ET is supposed to be a 15.3 so yes you should be able to beat the Raptor. If you're tuned up I would expect a 14.5 ET from the Challenger. Assuming those valves are 2.02, you have stock compression, stock head porting, an intake no better than stock, I would expect the .060 pistons to have poorer ring seal than a stock engine due to cylinder bores not staying round when warm. The camshaft is outdated but is a little better than stock and I think you have headers so realistically up from 275 to 300. Not trying to break your balls just being realistic.

Sheldon

 

[FredD]

Raptor ET is supposed to be a 15.3 so yes you should be able to beat the Raptor. If you're tuned up I would expect a 14.5 ET from the Challenger. Assuming those valves are 2.02, you have stock compression, stock head porting, an intake no better than stock, I would expect the .060 pistons to have poorer ring seal than a stock engine due to cylinder bores not staying round when warm. The camshaft is outdated but is a little better than stock and I think you have headers so realistically up from 275 to 300. Not trying to break your balls just being realistic.

Sheldon

 

[FredD]

Oh not offended. I appreciate every opinion. Did you take into account the engine is a 1968 340 x head?

 

[RUNCHARGER]

Yes I did. The 68 340's with the X-head and I would think 9.5 actual compression made 275. They had a really good intake manifold but the AVS was second rate compared to your Holley carb. I believe you will have a bit less compression ratio with those pistons but you will gain probably 20HP with your camshaft and probably 20HP with your carb. So that makes 315 plus you have headers. I might be a bit low on my estimates I suppose but basically you won't be a huge gain from a stock 68 340. This is not a bad place to be, 68 340's in an A-body with 3.91 gears were a feared combination in the day, taking down many big blocks from all 3 manufacturers.

Sheldon

 

[FredD]

Yes I did. The 68 340's with the X-head and I would think 9.5 actual compression made 275. They had a really good intake manifold but the AVS was second rate compared to your Holley carb. I believe you will have a bit less compression ratio with those pistons but you will gain probably 20HP with your camshaft and probably 20HP with your carb. So that makes 315 plus you have headers. I might be a bit low on my estimates I suppose but basically you won't be a huge gain from a stock 68 340. This is not a bad place to be, 68 340's in an A-body with 3.91 gears were a feared combination in the day, taking down many big blocks from all 3 manufacturers.

Sheldon

See those numbers are much better . The intake is a high rise Mopar P4532851 (M1 single plane I believe) maybe more Hp . Thanks for the info.

 

[Hammer75]

Talk to Mike at MRL Performance. He is a Mopar small block specialist. Bought a 340 from him a year ago. Have not installed it yet though.

 

[sixpak340]

I have a 1970 340 Six Pak set up in my TA, It was just bored 30 over, stock cam, headers ( For the dyno only ) and stock distributor. Hit 300 hP
on the dyno.

 

[FredD]

I have a 1970 340 Six Pak set up in my TA, It was just bored 30 over, stock cam, headers ( For the dyno only ) and stock distributor. Hit 300 hP
on the dyno.

That's pretty good. 6 packs though. I really need to get mine Dyno.

 

[aussiemark]

I would be taking care of this engine who cares about the power it is producing just be happy it is in one piece and running, if something goes wrong you won't be able to rebuild it without fitting sleeves to the block $$$.

 

[hot metal]

I can only give you an idea based on my '71 340 Cuda street/strip car which was all stock (no's car) lthr interior etc., apart from Centerlines, a 3500 stall converter, Holley SD intake, 750DP, .484"/284 purple hyd., 3.55 gears posi and 26" slicks. The car hooked well and ran 13.3's@101 in the 1/4, at 3550lbs with me?, never weighed it...that = 300hp fly hp+/- according to the Wallace calc. As said you need to get the car to a track 1/8th is ok, 1/4 best and get your best mph and weight with you in it, thats more a real world idea of the hp your making on the day under those conditions and altitude, but use tyres that will hook the car...
We later installed an 850DP, 2"spacer, DC .590"/312 solid purple cam, 1-3/4" race hdrs with some 4.30's, 10x28's and a 4200 converter, it then ran 12.39@108 computes to 360hp.

 

[moper]

I'm only looking at the bills and the pictures... I'd bet money it's around 300 at the crank. IMO, there are some steps missing from the build labor, and along with mismatched (intake and carb) or plain poor performing stuff (air cleaner assembly and cam), it's not near where it coulld be.
The two most important things tho is you like it, and there's room to improve.

 

[FredD]

Thanks guys, I'll try to have it dyno this summer. I might hit the local 1/8 mile to.

 

[fk5aar]

If boring .60 over only made u 5 more hp I would be very surprised.