btharbold

Hello,

I have been reading through pages and pages of good material on here regarding the various builds for a fairly stock 327. I want to build a good strong 327/365 for my 65 coupe. I want to retain the stock 11:1 compression and use an original 30/30 solid grind.

It seems that the best piston option is the Speedpro forged unit LF 2166. From what I can tell it only is offered with a pressed pin option? I plan on using aftermarket rods and was looking at the Eagle ESP lightweight H beams, but they use a floating pin.

Does anyone know if the Speedpro pistons come with the grooves machined for pin locks or would I have to get different pins and have the pistons machined? I like the idea of a full floating pin, I am going to spin it up, and will take all the gains I can get. Or is there some other piston that would be better to use with the stock deck height and dome volume that will allow the floating pins?

Otherwise I am looking to use 461 heads, stock type springs, pocket port, 2.02/1.6 valves, stock intake, 2818 carb etc. I was thinking of throwing some ARP main studs in there. I cant really see the need for the program 4 bolt caps, I am not stroking it out, anyone have thoughts on these?

Thanks

Brad Harbold

wolfman64

I have an original aluminum intake for the 327/365HP engine for sale if you are interested. Send me your email if you'd like some pictures.

Wolfman

NOM61

There are other piston options.
It just depends on how much you want to spend.
I bought Speed Pro Power Forged "LW" lightweight pistons for my 302 and the weight variance was so bad my machinist almost refused to balance them.
I wish I'd spent a bit more and bought Wiseco or SRP.
SRP has a forged 12cc pop up piston with a floating pin for just a bit more than Speed Pros. Part no. 147752 for .030 over.
You can always adjust your compression ratio with your head gasket.

DT

65tripleblack

For the kind of build that you're talking about, I believe that you're wasting your money on fancy pistons.

But, if you lose the boat anchor carb/intake manifold setup, and install a set of headers, then these are what you should be looking at:

http://www.jepistons.com/Catalogs/SR...-327_dome.aspx

The net dome volume on these is larger @ 12cc than the FM @ 5.3.............but these are a MUCH better piston. They are lighter, come with super light pins and use narrow rings.

I HIGHLY recommend these. If you use tight quench and open your chambers to compensate for the bigger dome, you'll have a potent little screamer. The domes can be machined.

btharbold

Thanks for the replys guys. Wolfman, I already have the intake from my L 79 setup, it was my understanding that the 350 and 365 HP intakes are the same. Thank you though.

With regard to the SRP pistons it looks like the dome volume on their 327 piston is 12 CC. I am not opposed to using the better piston, I just dont want compression to get too high. I like the idea of the lighter piston and the better ring pack. I assume these would accept floating pins? I could also possibly machine off some of the dome?

Does anyone know if the Speedpro pistons are machined with grooves for the spiro locks? I know they are listed as pressed pins but...?

Thanks

Brad

robert miller

get the SRP that is what I just put in my new rebuild 327 60 over 365. They are nice pistons...

BLOCKMAN

We have done quite a few of those builds over the years and it is hard to find pistons, We have been using the Keith Black Forged pistons and they offer one for a 6 inch rods as well!!!!

Here are some links to look over

http://kb-silvolite.com/icon/icon.ph...tails&P_id=378

http://kb-silvolite.com/icon/icon.ph...tails&P_id=380

With a 3.250 stroke the 4 bolt caps are not needed.

If your boring the cylinders and not decking the block find a shop that can bore of the mains instead of the decks, Boring off unsquared decks is not really recomended in a performance build.

There are shops out there that can deck your block with out cutting of the VIN number. So far I have never seen a GM deck that was flat from the factory.

A line hone is recomended as well more so if your changing to a stud kit.

ON the rods more likely then not both ends will need to be sized for your bearing clearance and wrist pin clearance.

And check the pin bores in the pistons as we have had to hone them for proper sizing.

Balancing is a must

Last if you are boring and honing spend the extra money and your block plate honed using the same gasketand hardware you will be using in the end build as ring seal is key with a 11:01 performance engine.

Hope I have helped and good luck with your build

Carl

Donny Brass

I run the Speed Pro Pistons..... and I would not recommend them to be used as an ashtray.

MikeM

For what reason? Just curious as I have them also.

robert miller

I have always be told and seen from 3 or 4 guys in past years using these pistons were junk. Have you had any problems with them..Plus one guy got a set and was so far off couldnt be balancing them.

BLOCKMAN

So far we have seen no balancing issues with them and have worked fine and these are the forged ones not the hypers as I try to stay away from them!!

We have used there 383 pistons in some builds and we did not ever see a problems and one was built for a marine application and that was 2 or 3 years ago and no problems so far.

Now the Speed pro stuff thats made in Mexico I have heard and seen issues with those pistons and have seen balance issues with through other shops we have balanced for but not 327 pistons.

If we got a set that was not right we would send them back and get a better set!!

robert miller

Yes the hypers in KB is junk for sure you get what you pay for. But these were in the forged for the 350 and 400 chev ci builds that I saw was bad. Glad you have had good luck with them...

Donny Brass

the wieghts were off, and they are a ton heavier than even the stock piston......

they will last forever, but at a cost

NOM61

Ouch! At least the LW's were lighter than the orignial TRW's for all the weight hassel!

DT

Scott Marzahl

The 2166s are not cut for spiro locks but you can have them cut like Mark did. I recall that he had Arias pistons cut his, not sure that floating pistons are going to buy you much. These things spin to 7K regardless of press or floating.

BLOCKMAN

Interesting the ones we have used must have been lighter then the stock pistons as we have always had to take weight out of the crank which tells me the pistons are lighter if they were heavier I would be adding weight to counter weights.

Scott Marzahl

That is interesting because the newer design 2166 piston has the shortened and rounded off skirt unlike the OEM piston with that long tab that sticks down.

NOM61

Are the pistons you're looking at part # L2166NF 5.3 cc dome 580g?
These are pressed pin - no grooves machined - its one or the other.
You can have the grooves machined in the pistons, but that would be a huge waste of money on an inferior piston.
For the cost of the machine work you can upgrade to a better floating pin piston.
All of the alternative pistons mentioned so far have floating pins as will any modern performance piston.
As long as it isn't a hollow dome piston you can always machine the dome.

DT

MikeM

My crank didn't get any weight added to it either and it had a factory balance with the stock domed pistons.

I was just curious what might be wrong with them.

I can't think of much reason why anyone would want floating piston pins on a street engine.

midyearvette

about the piston pins
there is no advantage at all for a full floating pin on any build....it just makes it more convenient when building or re building an engine.....