Yet another cam question...

#24
Yes,the springs and pushrods have to match anytime you do a cam change.If your engines original rockers are in good shape,you'll be able to use them with that cam.DO NOT attempt to use the aftermarket stock rockers,they're JUNK,even on a stock cam and springs.:deal
If you go with the 0950 I would use stiffer springs and be sure to use chromoly push rods. Ask me how I know:dunno
I was just out in the garage and took a few pics of the heads. When I got this car in 2004, it looked to have been gone through at some point. Looks to me like it has dual valve springs installed and they look like Comp Cam units. The heads were just gone through and I told the machine shop guy to basically just get them up to specs so I can put it back in service. I told him I wanted hardened seats as well. Thoughts on the valve springs in there? Especially as it pertains to running a 0950 cam in the engine?
 

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#27
Say I didn't want to change out all the valve springs and machine the heads out for bigger valves, because I already had the machine shop go through the heads and don't want to get that far into this car at the monent but do want to get it back on the road as a good-running cruiser and work in progress so that I can put my '54 Bel Air that is frame off at the moment back together, is that 0950 cam too big to be ran in there? I'm not looking for performance, really, I realize the way my 348 is currently set up is pretty limited. I'm looking for a good-running engine that looks good and maybe get a good little lope out of the exhaust while I'm replacing the worn out stock spec cam that was in there. I like the ideas on reworking the ol' 348 with a 409 crank and redoing the heads to flow better, but that's not in my budget or plans at the moment. Maybe once the '54 is done and I put more money into the El Camino. With that said, is something like the 0950 cam feasible in a bone stock 1960 348, or should I just stick to a station wagon cam? If so, what station wagon cam would you recommend? I just thought a little lope with the 12-inch glasspacks would sound great, and since I was recommended to replace the old cam in the engine by the machine shop, I figured I'd explore the possibility of getting a little bigger one in there. I've been wrenching on cars long enough to know that pretty much any modification causes a chain reaction, but was hoping to be able to get away with a mild cam.
 

Don Jacks

Well Seasoned Member
Supporting Member 3
#28
This cam will work fine in an otherwise reasonalibly stock 9.5-1 engine.Have your head guy check for about a 1.73-1.75 installed height ,with about 115-120 on the seat,and 275-290 open .Also,the max.lift when using the stock rocker ratio of 1.75-1 is .525 so that clearance needs to be verified.Those springs just might work.
 

4speedman

Well Known Member
Supporting Member 1
#29
Without the paperwork for the springs only way to tell what they are is to have them tested. You might want to shy away from the hardened seats and just run stainless steel valves.
About testing the valve springs,how do those testers that work in a vice and have a dial readout work out.I have not used one and was thinking of buying one,a customer of mine just had a valve spring problem with a small block on a set of heads that were just worked by a machine shop,i don't think they[machine shop] pay much attention to spring tension on a normal valve job.
 
#31
This cam will work fine in an otherwise reasonalibly stock 9.5-1 engine.Have your head guy check for about a 1.73-1.75 installed height ,with about 115-120 on the seat,and 275-290 open .Also,the max.lift when using the stock rocker ratio of 1.75-1 is .525 so that clearance needs to be verified.Those springs just might work.
So say I bought these set of springs, can I just swap them out with the ones on there and be good to go? Again, I feel like a dumb ass asking these questions, since it's stuff I should've learned in high school auto shop, but I never took high school auto shop, I stuck to auto body instead.

http://www.speedwaymotors.com/Speedway-Racing-Valve-Springs-1-25-Inch-O-D-Set-16,88.html
 
#32
:yupAnd since you're going to replace those 2 piece valves[:pray I hope] anyway,it doesn't cost any more to go up to the 2.09 in.,1.725 ex. valves.Show Cars has them for 159.95 in all the stock 348/409 valve sizes.Your engine will love it!:love
How can you tell they're two piece valves? Is that what the "TP" stamping means?
 

models916

Well Known Member
Supporting Member 7
#33
The spring in the pic is a single with an inner dampener. Unless your machine shop has done 348/409 valve seats, he is going to ruin your heads when he hits water. Stainless valves are 1 piece and don't really need the hardened seats. Serdi valve job with multi angles is the way to go to pick up some air flow. JMO
 

Clint

Well Known Member
#34
About testing the valve springs,how do those testers that work in a vice and have a dial readout work out.I have not used one and was thinking of buying one,a customer of mine just had a valve spring problem with a small block on a set of heads that were just worked by a machine shop,i don't think they[machine shop] pay much attention to spring tension on a normal valve job.
I have never used one. I have my machine shop test them for me. You are correct I don't think that they pay much attention to the springs either on a normal valve job.
 

Don Jacks

Well Seasoned Member
Supporting Member 3
#36
If those are stock valves,or stock replacement valves,they are 2 piece valves.The material in them is incompatable with unleaded gas and will not live long,and they have a tendancy to break.Those springs that you asked about will work with the cam that we've been discussing as long as they've been set up correctly.One question is what are you doing about head gaskets,and what is the distance between the top of the piston at top dead center and the top of the block?
 
#37
If those are stock valves,or stock replacement valves,they are 2 piece valves.The material in them is incompatable with unleaded gas and will not live long,and they have a tendancy to break.Those springs that you asked about will work with the cam that we've been discussing as long as they've been set up correctly.One question is what are you doing about head gaskets,and what is the distance between the top of the piston at top dead center and the top of the block?
Honestly, I was planning on assembling the short block and going from there. I will say that the top of the pistons were close to the top of the block, so I might have to figure that out once I'm there. Otherwise, I have some FelPro's that came in an engine gasket kit.
 

Don Jacks

Well Seasoned Member
Supporting Member 3
#38
Please do measure that.The reason being that just about all the Fel-Pros,as well as the other gaskets made now are too thick.The minimum quench area[the distance between the piston top and the cylinder head ]is about .034 but there's a maximum of no more than .060 that must be taken into account.Failure to do so will make the engine much more detonation prone.In the case of my 380,after the block decks were squared,the pistons came in at .014 down,and the only gaskets that I could get rather cheaply were about .050 and up.Show cars to the rescue as they recently bought out somebodys stock of the original steel shim gaskets which come in at .022[giving me a quench of .036].They're a little pricey at about 43.00 each,but the only other option was Cometic gaskets at .030 which come in at about 100.00 each.If your gaskets are from an older set,they may come in at .040 or so.The thing here is under no circumstances do you want more than a clearance of .055.Measure the gasket thickness and subtract .003 from the measurement to arrive at your compressed gasket thickness.Add the numbers up and see what you have.
 
#39
Please do measure that.The reason being that just about all the Fel-Pros,as well as the other gaskets made now are too thick.The minimum quench area[the distance between the piston top and the cylinder head ]is about .034 but there's a maximum of no more than .060 that must be taken into account.Failure to do so will make the engine much more detonation prone.In the case of my 380,after the block decks were squared,the pistons came in at .014 down,and the only gaskets that I could get rather cheaply were about .050 and up.Show cars to the rescue as they recently bought out somebodys stock of the original steel shim gaskets which come in at .022[giving me a quench of .036].They're a little pricey at about 43.00 each,but the only other option was Cometic gaskets at .030 which come in at about 100.00 each.If your gaskets are from an older set,they may come in at .040 or so.The thing here is under no circumstances do you want more than a clearance of .055.Measure the gasket thickness and subtract .003 from the measurement to arrive at your compressed gasket thickness.Add the numbers up and see what you have.
Good info, thanks yet again! It did have steel shim gaskets in there when I tore it down.
 
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