THIS IS A "I NEED BETTER PISTONS THREAD.."ADVICE NEEDED!!!

[Goldfinger71]

Hello all,
Well here is the problem.When I bought my car it didn't have a motor or tranny.I got a 72 steel crank for 440 out of a Newport.It has a stock bore(63,000 mile motor didn't need it)and it has the original pistons(very low in the hole with I think 8 to 1 compression )Here are the specs of the engine:
484'lift MP cam and lifters(im going back with the factory A/C)
steel crank turned 10'
346'heads with a 3 angle valve job with new springs
high volume oil pump
double roller timing chain
milodon deep pan
windage tray...and a few other small odds and ends
This is how I bought this engine.I bought a performer rpm for it.I have a 2800 stall converter.As far as the rear it is 4:10 in a 489 case(this gear will be replaced with a 3:55 or a 3:73 gear)....im keeping the 4:10
To wake up this engine what pistons do I need to go with?(TRW 6 pack pistons # 2355?)What else would I need?

Here is a pic of the engine.I want to run just as good as it looks!
Im on a budget as well so be gentle with me!
This is primarly going to be a street/show car with an occasional strip duty.
ANY HELP/SUGGESTIONS WOULD BE VERY MUCH APPRECIATED!

[firefighter3931]

Good looking engine Goldfinger  The sppedpro 2355's are a tough, durable replacement slug that will serve your needs well. Using those will bump up your compression into the 9.3-9.5 range which is fine for pump gas. The speedpros are very close in weight to the factory pistons so balancing is simple and inexpensive....i highly recommend doing a balance job when you swap out the pistons. If the rod bolts haven't been upgraded then go ahead and order up some arp rodbolts and have the rods reworked. You'll want to use Moly rings on this build as well....the speedpro moly's are excellent.

With a good balance job and upgraded rod bolts you can spin this up to 6k all day long and not have to worry about it. The 284 cam will be done making power at that rpm level anyway, so there's no need or benefit to spinning it any harder. Hydraulic lifters become unstable past 6000 anyway....another reason not to over rev the motor.

I have basicly the same setup in mine and that engine made 560hp with the ported e-heads, a big solid cam and roller valvetrain. We spun the motor to 6500 on numerous pulls and it held together fine.

Good luck with your build. 

Ron


Ps. Nice meeting you at Carlisle 

[Goldfinger71]

Firefighter',
Nice meeting you as well.I have a few questions.(1)The speedpro 2355 state that they have an .030"overbore.Will this matter since the engine is a stock bore?
(2)It also states that the pistons have a 10.17:1 compression ratio...is this a big deal?(You mentioned that the 2355 would have like a 9.3-9.5 compression ratio,from what I read(on the Jeg's site)those are for the stock type pistons with a different part number.
(3)Since the engine is going to be torn down partially,is there anything else you would suggest?..I am also assuming that the factory connecting rods are o.k for my application?
                                                                                                                   Thanks for the help! :icon_smile_cool:Larry
                                                                                                                                 

[firefighter3931]

To answer your questions Larry ;

(1) The 2355's are available in several bore diameters. When you have the block torn down, have a machinist measure the cylinders with a bore dial guage to see how much taper you have. You might get away  with a quick hone job, but it might also need an overbore. I wouldn't order pistons until you know what you've got.

(2) the 10.17 compression ratio is for a closed chamber 78cc cylinder head. Your open chamber heads will be 88-90cc so that will drop the static compression ratio down a little, which isn't a bad thing unless you like buying race fuel. 9.5:1 is considered the safe limit for pump gas with iron heads.

(3) the stock rods are fine as long as you balance the rotating assembly and upgrade the rod bolts. I would also upgrade to a high volume oilpump, the hemi replacement oilpan/matching pickup and a windage tray. The extra 2qts of oil won't hurt a thing.


Ron

[Wakko]

I'd get rid of that chrome tstat housing if I were you.   Sorry, that's the only advice I feel qualified to give. 

[Goldfinger71]

Thanks Firefighter!
Wakko,why do you say dump the chrome thermostat housing .......leaks,looks ugly?

[andy74]

Thanks Firefighter!
Wakko,why do you say dump the chrome thermostat housing .......leaks,looks ugly?

Larry, the chrome thermostat housings almost always leak,and they are a pain in the ass when it is all over your freshly painted and detailed engine bay!,thanks again for the hook up on the rear bumper!Andy

[71charger_fan]

I tossed my chrome water neck years ago because I couldn't get it to seal. Tom, whose '74 was parked next to me at Carlisle, was in the process of tossing his chrome neck and putting an iron one on Saturday afternoon because of being sick of the constant leaks. I'm sure they don't all leak but every one I've seen has.

[dodge freak]

Mine leak as well. Some guy on e-bay sells stainless steel ones that he claims looks like chrome but do not leak for like $38 plus shipping-too much for me but sounds like it should work.

[Chryco Psycho]

for what it is worth I agre with Ron the 2355 piston works

[BrianShaughnessy]

Mine leak as well. Some guy on e-bay sells stainless steel ones that he claims looks like chrome but do not leak for like $38 plus shipping-too much for me but sounds like it should work.

The stainless thermostat housings from Weldtech WORK very well,  do not leak,  do not bend, do not chip, flake or rust.      It's the last thermostat housing you'll need (1).



Note 1.   No whining from the facotry correct painted engine folks