In a 454 what piston are you using? Whats your compression ratio? Piston to deck height? Final chamber cc's? I've heard some people comment on the lack of piston-to-valve clearance with some hi-po pistons. I see that Ross has some pistons that are supposed to be designed to help that situation. Is anyone here using Ross pistons in an open chambered 454? How are the SRP's?

Rod, I'm using the SPR "medium Dome" slugs and they are just giving .100( no head gasket) on the exhaust with the cam in +6, 110 lsa .580 net lift. The heads are NOT 049/781,but 074 OC heads milled rather a bit to 112.5cc.

last motor i had was 454 with 781 castings, heads were milled 10 thousands and came out to 120 cc chambers. pistons were trw L2307 12.3.1 advertised compression with a .039 gasket cam was a 620 lift and plenty of valve clearence! motor combo made 625 horsepower...mike

That's good info guys, thanks!

Any others?

I know there was someone here that said they had problems with TRW #2465 with a relatively mild cam.

i used the l2465 trws on a 454+.060 with a 595 lift solid cam, the heads (781's) were milled .025
the block was .025 in the hole. i had .080 clearence on the intake valve with head gasket (.040) installed and .024 valve lash. a bit close . you may consider to put 1 piston /rod together and check first no matter which piston you use . that way before everything is balanced and assembeled you can notch the piston a bit to be safe.on my current motor i had the block 0 decked , the heads milled .025 and a 612/630 lift cam. needless to say the piston hit . i had the piston releived on the intake valve side .120
and now have 125 clearence with head gasket and valve lash. hope this helps ray

I had used a KB 203 I think. .133 dome and the heads were around 120cc 9.0 comp. Now have SRP's but more dome and they came with the 489 kit from Eagle between 9.7 with 124cc or 10.2 with 118.

mr68, thanks! graemlins/thumbsup.gif

You hit on exactly the situation I'm concerned about. So, I guess that helps me clarify my question. Isn't there a piston available to give enough clearance so you don't have to have the extra machining done? Maybe what I'm asking is unreasonable to expect when you realize that every motor going together with a particular piston could have different needs for piston-to-valve clearance.

We originally ran a set of 049's with flat top TRW pistons 118 cc open chamber heads about 9/1 compression, alot of tork good street heads. (now setting on garage floor. We are now running a set of 69 427 vette heads with 219 intake 188 exhaust that have be ported and polished and upped the compression to over 10/1. This helped lower our E/T from a 13.71 to a 12.30 1/4 mile. Although it was not the only change we made. :rolleyes:

rod, not to my knowledge. i guess it becomes a custom situation with each individual setup. my guess is if you mill the heads and deck the block and use a hi lift cam (over .580 lift) you will probably need to have at least .100 removed from the intake area of the piston. ray

BTW, the SRPs ( although a bit spendy) are much lighter than the TRW/Speed Pro forgings. Neglected to add my slugs are only .007" down the hole.

don't want to veer off of the subject ,but you can get the 2465 trws in a light weight version. ray

Not off subject at all Ray. Supply of any 427 TRW slug was really ifffy when I redid my mill last year. Would have liked to spend less than $535 for 8 pistons. Bit much for a street motor IMHO.

I'm running K/B 257s, hypertuetic, with a 454 .030 over,zero decked,.039 head gaskets with 781s that are opened up with 2.19/1.88 valves. The heads are shaved to 116 ccs,and I am running a Crane hyd. roller 296/304 adv.,234/242 @.050. It has .610/.630 lift. No clearance issues at all, Pistons come heavily cut for valve clearance. I bought these pistons because the TRW L2399s that came in the engine when I bought it wouldn't clear the valves.Fortunately it wasn't fired up yet and I took it apart to check it out.

I use the SRP 10.25 mid-dome with my 049 heads which are milled .030 for a 118 cc chamber (same as 781). These are good forged pistons and just as light as the JE 599 grams. I use them with a 650 lift solid roller and piston ot valve issues. Runs on pump gas just fine.

TRW and Weisco are very heavy, over 700 grams for almost the same money. Go with forged pistons, it's cheap insurance!

mabye the srp's are the better way to go. if you have to releive the trw's that will set you back
a few bucks anyway.summit sells the 2465's for 319.00. the standard pistons are a bit heavy ,but i did run mid 11's at 118 mph in my 4000 lb 70 chevelle.

Originally posted by mr68:
mabye the srp's are the better way to go. if you have to releive the trw's that will set you back a few bucks anyway.I agree, that's a good point.

Click here for a sweet deal on SRP pistons (http://cgi.ebay.com/ebaymotors/ws/eBayISAPI.dll?ViewItem&rd=1&category=33623&item=2443624892)

Was browsing eBay and found this, looks like about 150.00 or more off the SRP's