CCC friendly aftermarket cam for N/A 231/252

charlief1 said:
The 2nd gen s-10 blazer and 4th gen F body cars all have the 7.5" except for a very few of the 4wd blazers.All of them have 28 spline axles but none of them will fit a G body car. The turbo regal after 84 came with 8.5" axles and 28 splined shafts and the axles will fit a 7.5" axle if the carrier has 28 splines. You take the carrier out of the F body or blazer and put it in your axle then get the 28 splined shafts out of a turbo regal
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Now it makes sense! thanks
 
Jeg's has the springs for 39.99 and free shipping. Summit has a 10.00 handling fee if the order is under 99.00. Those are the springs Comp recommends for their mild cams. 92 lbs. on the seat at 1.700" installed height. Yes, just bolt the rockers back on.
 
I'm still working on the intake and the have excess material around the primary bores removed along with the material between the primary and secondary bores. Now I'm working on the material in the secondary bores and making good progress on them. I only have a rotary tool and some bits for it but I do have a flexible wand attachment and it's proving to be priceless to me. Would it be worth the time to port match the intake to the valley pan and heads? Since it's been suggested to port the bowls a little I figure it wouldn't hurt to port match and maybe smooth the exhaust ports on the heads to help exhaust gas velocity. From what I understand the stock heads do not flow well "as is" so improving flow is important.

Also why does Edelbrock say to use stock springs with their cam? Usually cam makers suggest something stronger than stock. How do the Comp 980's compare to the stock springs in terms of pressure? For the seals I'm going with Vitons but not sure of size till I get the heads to the shop and see what guides they put in.

The Hooker GN headers are nice but for 875 bucks (ceramic coated) and not needing the pipes connecting the headers and turbo, the price seems a bit much unless I can find someone to buy the pipes to help offset some of the cost. I'd rather go with them over the Hedman headers as they're full length and I don't think I need full length for a mild build like mine. My choice of muffler is another Hooker Maxiumum Flow in 3" inlet/outlet, the 2" inlet/outlet version on the car now is pretty quiet at idle and at cruising speeds and it helped the 3.8 breath a little better so I figure why fix what isn't broken.

I also notice I have a build up of carbon in the EGR passages, could i put some seafoam in them after I'm done with with the intake to thoroughly clean them? Do I need some engine cleaning type brushes to get the gunk out?
 
The Edelbrock cam is a pretty mild cam, but I would not use stock springs. The 980's have more pressure than the stockers and will work fine. You can use spray carb cleaner and air pressure to clean the EGR passages after you get the big chunks of carbon out. I never tried Sea Foam, but it might work. Full length headers will give a little more torque down low than the shorty type. Shorty headers should give more top end power. I have used both and can't really tell any difference on the butt dyno.
 
The passage coming from the EGR between the secondary bores was kinda choked with carbon build up and I got most of what I could get out with a screw driver and a hammer. I might open up the intake a bit more to get better access to the passage, so far I haven't done much between the left and right sides except for smooth everything out and cleaning up where the cuts were made. It already looks quite a bit like Charlie's intake in his thread, I just have to finish the secondary bores and then smooth the ports.

If full length headers will give me more down low grunt, I'll just get a pair of ceramic coated headers (600 dollars!) from Hedman. Any suggestions on a high flow catalytic converter?
 
I don't use a catalytic converter. My engines go in a 74 Toyota truck, so no converter needed. Florida has no emission inspections either. I saw high flow Magnaflow converters in the Summitt catalog for $70-80. A 3" single exhaust will sound good with a converter to help quiet it down. It will be louder than a 2" exhaust. I went from a 2 1/2" Flowmaster to a 3". I had to put a big block 3" Flowmaster on it because it was pretty annoying with the short one. I run a 3" Magnaflow now since the Flowmaster rotted out, and I can hear the radio. Porting the manifold to the gasket will help high RPM power. The instructions for the old Kenne Bell intake used to say not to do any porting on the manifold because it would kill the velocity of the mixture at low speeds. The passages were really small. I ported both of mine to the size of the heads and it is fine. I ran one for years unported and it ran fine on a 3.8, but since I had ported heads or GN1's on my 4.1 strokers, I felt it would be better to get all the flow I could. Without a flow bench, it's a crap shoot, but common sense says it should be better to match the ports.
 
MY85pontiac said:
Would it be worth the time to port match the intake to the valley pan and heads? Since it's been suggested to port the bowls a little I figure it wouldn't hurt to port match and maybe smooth the exhaust ports on the heads to help exhaust gas velocity. From what I understand the stock heads do not flow well "as is" so improving flow is important.
Click to expand...
Any help with air flow is worth the extra effort. Port match does help some but the bowls are 99% of the issue with the heads. Don't forget to cut the guides down so very little sticks out into the bowl area.

MY85pontiac said:
For the seals I'm going with Vitons but not sure of size till I get the heads to the shop and see what guides they put in.
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Have the guides cut for standard SBC seals. They'll be cheap and work find with the heads. Make sure to replace the exhaust valves so the step at the top doesn't rip the seals up.

MY85pontiac said:
The Hooker GN headers are nice but for 875 bucks (ceramic coated) and not needing the pipes connecting the headers and turbo, the price seems a bit much unless I can find someone to buy the pipes to help offset some of the cost. I'd rather go with them over the Hedman headers as they're full length and I don't think I need full length for a mild build like mine. My choice of muffler is another Hooker Maxiumum Flow in 3" inlet/outlet, the 2" inlet/outlet version on the car now is pretty quiet at idle and at cruising speeds and it helped the 3.8 breath a little better so I figure why fix what isn't broken.
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Check the forum for sale section and you may find a set cheap. I've bought 2 sets for less than $150 so I know you can find them.
MY85pontiac said:
I also notice I have a build up of carbon in the EGR passages, could i put some seafoam in them after I'm done with with the intake to thoroughly clean them? Do I need some engine cleaning type brushes to get the gunk out?
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My land lord works at a car wash and he brought a 5 gallon bucket of the engine cleaner home for me. I dipped the intake into it and left it all day. When I pulled it out I used a high pressure washer to blow the carbon out.
 
charlief1 said:
Any help with air flow is worth the extra effort. Port match does help some but the bowls are 99% of the issue with the heads. Don't forget to cut the guides down so very little sticks out into the bowl area.


Have the guides cut for standard SBC seals. They'll be cheap and work find with the heads. Make sure to replace the exhaust valves so the step at the top doesn't rip the seals up.


Check the forum for sale section and you may find a set cheap. I've bought 2 sets for less than $150 so I know you can find them.

My land lord works at a car wash and he brought a 5 gallon bucket of the engine cleaner home for me. I dipped the intake into it and left it all day. When I pulled it out I used a high pressure washer to blow the carbon out.
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I was going to cut the guides down in the bowl area and have new guides put in to keep the full length support of the original guide without all the excess material in the way like the original guides. I've been studying pics of before and after of ported bowls and bronze guides are much smaller in diameter than the original guides so I thought porting them first then taking the heads in since I wouldn't have to work around new guides. Also it seems most of the porting is between the guide and the seat on the long side of the port with a little smoothing on the short side. I don't want to lower compression but would smoothing the combustion chambers be worth the time? The problem I'm having is the pics I'm looking at regarding porting the bowls is that the pics aren't taken at the same angles, the before and after are at different angles and different lighting making it hard to really tell what has been done besides removing material where the guides are. I have a pretty good idea where to do the porting but better pics would be more helpful. I might pick up an extra set of heads to work on so I can compare the unported next to the one I'm porting and hopefully not ruin a head.
 
I've posted side by side of ported and un-ported heads before. Try looking in this section for a little head work under my name and you might find the pics.
 
charlief1 said:
I've posted side by side of ported and un-ported heads before. Try looking in this section for a little head work under my name and you might find the pics.
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I found a thread by you with some pics that are much better and show more clearly what I'm looking at. It looks like the valve guide area, a little bit above the valve seat all around and the bowl from the valve guide to the valve seat on the long side. Does that seem about right? What about the ports themselves, just smooth them out?

The more I work on the intake, Since it is a single plane, what the point is in keeping the divider? Would there be any harm in just making it an open plenum?
 
The ports really just need a good smoothing and straightening but the bowls are 99% of the work. I'm a bit of a perfectionist so I spend more time on the ports than is really needed to get them as perfect as possible. I can do a set of bowls in about 8 hours since they're as open as they are, but the ports take longer to equalize because they're not as open. I've got some long burs just for this purpose.

It's a dual plane, not single. Single would be completely open. When you start cutting at the front you expose more of the EGR passage which equalizes the vacuum between the sides of the carb better.
 
With the holes in the divider it might as we be a single plane. That's why I was wondering what the point is in having it if it's not a real divider. If it was removed the air/fuel coming from the other side wouldn't be obstructed. I'm curious how that would affect performance.
 
MY85pontiac said:
With the holes in the divider it might as we be a single plane. That's why I was wondering what the point is in having it if it's not a real divider. If it was removed the air/fuel coming from the other side wouldn't be obstructed. I'm curious how that would affect performance.
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You'd need to weld up the hole to some degree since they're be a giant hole where the EGR comes in.
 
charlief1 said:
You'd need to weld up the hole to some degree since they're be a giant hole where the EGR comes in.
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Well, I could remove just the material in front of the EGR hole since most of it has a hole in the middle of it so removing that wouldn't make the EGR hole any larger. I could also trim around the EGR hole and not enlarge it. Definitely the material around the existing hole between the left and right ports can be gotten rid of and that alone might do more to even allow more air/fuel to reach from the opposing side. Especially since it's between the primaries that may help more than removing the divider between the secondaries, those things are so large I doubt they have a problem feeding any port.
 
140607_001.jpg


Polished secondary,
140607_002.jpg


Good enough?
 
See of you can smooth and round the bottom out a little more. Getting rid of that sharp corner really helps the flow.
 
I've rounded it to a 1/4" radius or so but I'm working up to 3/8" and see how that feels and looks. I'm almost done with the other secondary and I'm removing the piece in the middle between the gap they put at the bottom of the divider and the top of the divider. I don't think any more really needs to be removed but if I get a 1" spacer I'll probably remove the part at the top and angle the part above the EGR hole downward.

I'm wondering if adding some JB weld to fill in the voids around the front carburetor bolt hole bosses to turn them into smooth transitions into the runners would help since they'll be low vacuum areas and could affect air flow. I'm probably over-thinking this part but every little bit helps and I'm wanting to make everything smooth and eliminate areas that might create turbulence. Then again, adding JB weld could come loose and cause a lot of destruction.
 
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With the alky in current fuel, JB weld would dissolve and screw things up. You could get some long threaded bolts and run them all the way down.
 
Good work on intake, keep it up. Charlie showing your age?? Lol 4.1L 4bbl intake manifold is single plane for sure not a dual plane.
 
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