I've read somewhere (maybe here) that if a set of Cleveland heads had a dot and a 4 on them they were open chamber 4v heads. I took off my intake manifold today to reseal (or replace) it and I took a peek at the casting code on my heads. It said D1AE. According to this site: http://home.comcast.net/~jelerath/mustang/Specs/heads-fr.html they are closed chambered heads. But I have the 4 and dot stamped on it so I expected open chamber. I have the Tom Monroe "How to Rebuild For Engines" and in his table D1AE shows up as: 70-74 351C-2V and 71-74 400 . My 1974 is an H code on the VIN so it should have a 351 with 2V heads. The previous owner said the engine was rebuilt by a perfomance shop (he could be lying) so I guess they put an older pair of heads on. Also, do the rocker arms in the picture look stock for '71 heads. If so, anyone know the ratio? I have no idea what cam I have but I do have a dial indicator and am going to trying and measure the lift.
Need the suffix to the casting number - are they D1AE-GA? Look for the other letter or two and we can break it down further... Likely the statement was correct that a performance shop worked it and talked the owner into the the 4V heads. Be aware that your intake and exhaust gaskets are different with those heads than they would with 2V heads. The difference is huge and they don't interchange and can't be made to work one to the other. Those are the stock rockers and lifter arrangement. The rocker ratio is 1.73:1
Where are the the last 2 letters? Under a different intake runner? I got the 4v gaskets, they actually had them in stock at Advanced auto which was surprising. I just have to find a different intake manifold now as I don't think I want to put the Torker back in. I'd like to find something a little better in the lower RPMs. Any suggestions? Thanks
I'd have to pull an engine apart to tell you where to find the suffix, but... On further checking the heads you have are 4V open chamber - the closed chamber casting is D0AE. I use the factory cast iron manifolds correct to the application (351 CJ or 351 HO, spreadbore or Holley square pattern respectively - so I don't really have a suggestion. Have heard good things about the Blue Thunder manifolds, the Pantera build for the limited clearance mindset and they have high rise configurations as well. Not sure which is best. Have heard and read about an insert that you can put in the intake ports that improves the low RPM range of the 4V heads but I don't know anything about how effective they are. Sorry.
That's OK, under each intake runner there was different stamps. Maybe one of them has the last suffix. I'll check tonight. I see alot of posts about Blue Thunder manifolds on google, I'll see if I can get some prices on those. Last night I saw a brand new Edelbrock Performer 2665 for a 351C 4V for $25 free shipping on Amazon. It might be price mistake or fluke but I jumped on it and ordered it. If the order get's cancelled I'll look at the Blue Thunder more closely.
I took another look and under another runner was GA. So D1AE-GA is the complete casting #. I checked a couple sites and they say closed chamber heads: http://www.castingnumbers.info/site/browse/m/Ford/c/Cylinder_Heads/t/Cleveland_V8 but this site shows people with that same casting # who have closed and open. http://www.network54.com/Forum/119419/thread/1275006736/D1AE-GA+question+open+or+closed+heads- I guess the only way to be 100% sure would be to pull the heads. Edit: These heads have the same casting #'s and a dot so there is hope: http://www.ebay.com/itm/351-Clevela...Parts_Accessories&vxp=mtr&hash=item3a7d3642e6
Have seen them listed out as both and would agree - the only way to know for certain is pull them - not sure you want to do that at this juncture. I have two sources that read they are closed (quench) heads, and one source that reads they "could" be open chamber. Absent other indications on the need to remove them, I wouldn't. If you have some issues that would be better resolved if you pulled them though then go for it. Otherwise, it could turn into an awfully expensive "open and inspect" just to figure out what is there. But I think you answered yourself in your first post - you note that the dot with the '4' are in the casting and that is supposedly the sign that the heads are open chamber. That bears out with the engines (4) that I have available to look at - all the open chamber engines have the dot, the closed chambers just the bare '4'.
Hope? What are you hoping for, closed or open??? http://www.dscmotorsport.com/Cylinder/index.htm Scroll down and select the 4 Barrel Quench heads to see what Dennis is getting for a pair.
I'm definitely not taking the heads off at this point. My truck has some pinging issues. The closed chamber heads should bring the engine to a higher compression ratio than the open so that may have something to do with it. But I still have a bunch of other issues that might be causing it but in theory these heads would be more susceptible to pinging from what I've read. It kind of sucks that I don't know the compression ratio after the rebuild. But first, I wanted to replace the intake manifold since I believe I had an internal vacuum leak and I don't like the Torker anyway. I ruled out external vacuum leak in this thread: http://www.ranchero.us/forums/showthread.php?t=30723 . I'm hoping for closed chamber because they should make more horsepower and are more desirable from what I've read online. Who's Dennis? Is he a member here that runs that site?
Yeah, I'm really hoping I do. They haven't shipped yet but I was billed $24.95. Fingers are crossed... Amazon says: Delivery estimate: Jan. 10, 2013 - Jan. 15, 2013 Hope I get them by the weekend.
When is it pinging? All the time? Cruising on the freeway? Acceleration from cruising? All acceleration? Pinging is usually easy to correct.
Yes, a bit more HP with the closed chamber heads. Dennis Carrico does own DSC Motorsports - and is not a member here that I know of. Just did a lot of business with him in the past and he has been good to work with. Good luck!
When I first start it up, it doesn't ping. Once the engine warms up after 10 minutes it'll ping under load such as going up a hill and heavy accelerating. It cruises pretty smooth. Plugs are new, wires are new but I've got an HEI ignition if that matters. I tested the vacuum advance and it's working. I tried to correct it by changing the timing. It was retarded at around 5 ATDC if I recall correctly. The most advanced I could get it to run is 5 BTDC. I know that initial timing is way off what it should be. Could be the timing tape is off so I ordered a piston stop and I'm going to check to make sure the timing tape is correct once it arrives this week. Found a good how to video here: http://www.youtube.com/watch?v=bhIP5YKCgRE I've always put 93 octane in it. I was going to experiment by putting 100 octane (there's a place 20 minutes away) but that stuff is over $8 a gallon over here. So I got the manifold off, valve covers off and it's garaged and not my daily driver. Are there any other tests you recommend to check the valve train while its apart? I'm doing the TDC/balancer check and measuring the valve lift. All the pushrods look straight.
Try disconnecting the vacuum advance, and see if the problem goes away. If it does, look inside the vacuum tube on the distributor. If you see a screw head or allen hole, you have an adjustable advance. If it is, tighten the screw 1/4 turn, test, another 1/4 turn etc until the problem goes away. If deleting the vacuum advance does not get rid of the ping, your carb is running lean under load.
Thanks I'll try that once I get a new manifold back on. I tried tuning the carb but with the vacuum leak I had trouble adjusting it. Turning the A/F mixture screws had no affect . In the other thread linked above you said it probably wasn't running on the idle circuit and it looks like you were spot on with that. All of the symptoms I had point to this: http://www.crankshaftcoalition.com/wiki/Intake_manifold/cylinder_head_internal_vacuum_leak
Order got cancelled. I kind of expected that but I had to try. I called Blue Thunder and they had me call a couple of the resellers and it looks like their manifolds also might be in the higher RPM range for what I'm doing. It seems like it would be a pain in the ass to order as well. I called Edelbrock to ask about the RPM Air Gap manifold. I was suspicious because they say it fits both 2V and 4V heads. Their tech said there is no problem running them on 4V heads as long as I keep the RPMs under 6,500. I'm leaning toward this over the Performer Manifold that I originally ordered. http://www.amazon.com/Edelbrock-7564-Performer-Air-Gap-Manifold/dp/B000VDHZOA http://www.summitracing.com/parts/edl-7564/overview/make/ford
Vman, I'm curious about the manifolds you now have -- both intake and exhaust port openings are different for the 4v heads, but do the holes in your manifolds match the heads? I would never have guessed that a 2v manifold would be right on a 4v head, either intake or exhaust.
I only have 1 right now. The Edelbrock Model # is 2760 and shows up on Summit Racing as Torker II 4V. The holes match perfectly, they're both around 2.4" high. I'm ordering the Air Gap tomorrow. It's supposed to fit both heads but delivers less flow to the 4V. I did some "googling" and read mostly positive things about it from people who have used both the Air Gap and the base Performer. The price difference is $311 vs $250 so I'm going to give the Air Gap a try.
