https://www.fmmotorparts.com/fmstorefront/federalmogul/en/USD/Engine/Cylinder-Block-Components/PSTON-EnginePiston/Sealed-Power-Cast-Piston-(Carton-of-8)/p/PH273CP?categoryCode=PSTONEnginePiston#.W13gN7hG0iw Got curious so I googled those pistons. Pretty heavy total weight(piston isn't totally horrible but at 153 grams pins must be 3" long ).. so probably not very far off from standard stock OEM weights. Also has offset pins so be sure they are installed correctly with dots facing forward on both banks(check install literature to confirm). They are hypereutectic alloy so clearances can be run fairly tight.. which is one of the biggest benefits to running that alloy in the first place. Be sure to use the piston mfgrs ring gap spec's since hyper's can be gapped different than forgings. Hopefully your machinist knew about this intended piston design and didn't get carried away with final bore sizing for anything of forged design. If he did something like this without asking or knowing what he was final sizing the bores too?.. most definitely time to find a new machinist who knows and cares what they are doing. Good luck with it.
I just wanted to give this posting a quick update. I have since had some issues which are concerning to me. I had gotten the rotating assembly balanced by a new machine shop and am very happy with the results and also with the company who worked on it. Now the bad news is I have recently started the assembly but hit an issue right away when installing the cam, it did not spin freely at all in fact you had to use a socket with moderate force to get it to spin which it would then spin smoothly as long as you cranked it. I called my original machinist since he was the one who installed the cam bearings and he said: "that was normal". But after talking to my new machinist he said that is wrong... So I am told I must get the block line bored and have new cam bearings install I am about to purchase some more parts and was thinking about a stealth intake holley 650 carb and i had a chance to get some afr 165s which i might jump on.
They might have cocked a bearing when they installed them and distorted enough to cause a problem. If you ran it as is you would have problems in a hurry. My bet is new bearings installed by a competent installer would solve the problem.
I'm running that top end combination with a 750 Demon carburetor. You might prefer the 650 Holley carb for your intended purpose. I agree with RMiller, improper cam bearing installation should be the first item to check.
Ya thats probably what it is the machinist who installed them first didnt even have the cam when he was doing it so i will try that first. How does the motor feel with that 750 on it that seems to be a pretty big carb?
I had a 650 Speed Demon for several years prior to the 750. No change in 1/4 mile performance. The 750 is just a much finer operating carburetor than the ancient Craig's List 650. The 650 Speed Demon has a fuel evaporation issue that I have never been able to correct. If my Comet sat for a long period of time (as in days or months) the engine would not fire right away due to lack of fuel in the fuel bowls caused by evaporation. The newer 750 is much less an issue. According to what I have read on the web, fuel evaporation can be an issue with older Speed Demons. If I had an electric fuel pump it would mask the problem.
Still have the C4 with a 3,500 stall convertor. Runs 12.50s. Never trailered. Nice streetable combination. Check it out in the Garage section of this site.
Line boring the mains will have 0, nada, zilch impact on cam bearing bore alignment. My guess is you have some bearings installed a little skewed in their respective bores. Another thing to check is cam straightness, runout on a granite table of v-blocks made specifically for that task. Lots of cams get bent after grinding or when stored improperly.
do you think I could fix this issue myself or is it best to just let the machinist do this?Keep in mind i do not have the correct tool but could get one from a friend.
so possible change of plans. My dad and I found a pair of Edelbrock rpm heads, these ones specifically. https://www.summitracing.com/parts/...Fvt4QIWchh78bjT-2mfvScDiSU_SVkbhoCK48QAvD_BwE and we are thinking of going with these they are really cheap and leaves us enough room to get them milled and possibly have some porting done to them. I have read up what people like and do not like about these and wanted to see what you guys thought this would perform like with my choice of pistons etc. If we go this route we will have them milled to something like 54cc or 58cc. There were also some twisted wedge heads local for a pretty good deal aswell s might be another possible route.
You would first need to measure the bearings ID's and confirm that cam is sized properly per journal. Seems doubtful they could be swapped around into the wrong bearing bores but another thing to check is the right bearings went into their correct positions. SBF has stepped ID sizings from front to rear.. larger to smaller and a snap gauge should tell the tale when mic'd. Very tough to do this on a complete shortblock though. Just a quick copy and paste from an old forum post but looks right from memory. Ford Small Block, 351 Windsor & SVO Block Journal #1 – 2.080" Stock Ford Bearing Size Journal #2 – 2.065" Stock Ford Bearing Size Journal #3 – 2.050" Stock Ford Bearing Size Journal #4 – 2.035" Stock Ford Bearing Size Journal #5 – 2.020" Stock Ford Bearing Size
I don't think he does. Those are decent enough entry level castings but there are notably better offerings at that same price point these days. I'd pick a similarly sized trick flow or AFR piece over those if spending $1,700+ and then adding porting costs of at least another $500. IMO, just pick a better CNC casting up front and be done with it. I have a set of Trick Flows 170cc 11R head and they're already awesome pieces out of the box. These are the ones I bought. Kinda weird that they're cheaper than the Eddy's too. https://www.summitracing.com/parts/tfs-52515301-c00
I should have mentioned they are used from a Friend of ours for 650 for the pair. The link was just to refer to the heads that they are. He has also stayed he can throw in some ford svo 1.6 roller rockers for free.
