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Hey guys. I think I've finally decided on the engine I want to build for my 78. I'll be using the stock short block with new rings and bearings. The heads are D0VE-C's, ported, polished, 2.08int/1.75exh ss valves, Manley roller rockers and guide plates. The cam I'm thinking of using is a Lunati solid lifter .559"int/.572"exh, 236/246 dur at .050. I'll be using a Weiand Stealth intake and a Holley 750. Exhaust is Flowtech headers, 3" pipes and Flowmasters. The question I want to ask is, is this too much cam to run on the street in a daily driver? Actually, I won't be driving it every day, probably just on weekends and occasionally to work if needed. I'm open to suggestions and comments. This is my first real engine buildup. Thanks.
I think youre probably going to find that cam to be a bit on the big side. are you going to be using a high stall converter? if not, youll definitely want something a little smaller in that heavy of a vehicle. in that engine, going with a cam in the 220/230 range will give you as much 50 lb-ft of torque more under 4000 rpms, while only giving up 20 or so horsepower in the 5-6000 range (as opposed to the 240ish cam). i guess it just all depends on how much bottom end youre willing to give up, and how fast youre looking to spin it.
I agree with 83F2504X4...your going to need at least a 2400 stall converter and gearing in the neighborhood of three ninetys to four elevens with a 31 inch tall tire. Even more gearing if you run taller tires. When you say "stock bottom end" with your cam-head combo you'll be spinning the engine in the 6,000-6,200 range to extract the maximum power. Your going to need at least 10-10.5 compression ratio (KB pistons or forged), CJ style rods with ARP bolts and Clevite bearings, while you have it apart also use a high-volume oil pump. Deen
Thanks for the replies. Sorry, I should have mentioned all the parts I'm putting in there. I have a 4.11 and 4.56 locked rear to choose from for it(truck has 3.50's now), either a 2500 or 3000 stall converter(have both), truck/CJ rods, ARP rod bolts, Melling HV oil pump and Clevite bearings and rings. I was hoping to be able to use the stock pistons, but now after thinking about it, I'll probably get new pistons. probably get forged pistons, Compression should be in the 9.6-10.2 to 1 area(need dished pistons). I know what your thinking, why would I use the stock pistons? I don't want to spend any more than I have to(and already have). The heads are going to run about $900 when done(hard seats, bronze guides, valve job, valves, porting, surfacing) The block is in great shape and should only need a hone to make it good. I don't want to bore it if I don't have too. Does anyone have a suggestion as to which cam grinds to check out? I'll probably contact Comp this week and I've already contacted Lunati. Maybe go with a custom ground cam? Thank for your time, I'm kind of clueless here
Check with a custom cam grinder who knows your heads. Those heads have difficulty flowing 200cfm at .550 lift on the exhaust side even with an all-out porting job. Every shop has different porting standards, especially on 385 series heads.
Stock DOVE heads flow 135cfm max at .400+ lift on the exhaust side, so getting to 200cfm to accomodate your current cam selection will require hours and hours (read very expensive) of careful porting on the exhaust side.
I'm surprised the shop didn't take the intake valves to 2.19". Same price and even Ford recommended the 2.19" intake valve during that era. I'd be very careful that the hone pattern is correct on an unbored, seasoned block. You're putting some good money in it and new pistons, so why not line bore it instead of taking a chance on the rings never seating.
Thanks for the input George. The reason I am staying with the 2.08 intakes is that I've heard only a 5-10% increse in flow with a 2.19 valve. The machine shop told me that with the porting they are doing to the intake it should flow about 300cfm with the 2.08 valve. That's more than enough on the intake side. I can still go with the 2.19's if needed as I haven't bought the valves yet, but I will be ordering them either Monday or Tuesday. I believe they(machine shop) are only going to pocket port the intakes and do the most they can with the exhaust. I'll know more when I bring the valves to them this week. I'll probably end up taking the block in too. Looks like my budget just got upped for this build up. Keep the suggestions coming. Thank you.
Well, back to the cam, i think if it were me i would go with about a 225/235 (or maybe a tad bigger), the 3000 stall, and make shifts at 5500. im sure something in the 240 range would work well, but, as others have said, you would have to be spinning around 6k to make use of it, and it wouldnt pull as hard off the line. peak horspower shouldnt be too much worse, it would just come in earlier and drop off faster...whereas, youd be getting in the area of 20 more hp and 40 more lb-ft when the converter grabs. (can you tell i was playing with the desktop dyno?) =)
That cam will be fine, a 235* solid is acting more like a 225* hydraulic cam because of the lash being taken up. You'll only have to shift it at 5500 for good performance, 6000 in an "emergency". That bottom end will take 6500rpm, so you're safe. Nice buildup, should run very well.
Thanks for the input guys. I'm going to call Lunati tomorrow. And probably Comp, Crane, and Crower. I decided to go with 2.19" intakes also. They cost the same as 2.08" and it's only $30 more machine work. I've always heard that you can run a bigger solid cam than hyd. because of the valve lash of the solid. I might have a problem with the vacuum to run the power brakes. Probably have to get a vacuum can. I'll keep you all posted, I hope to have the motor done in 2-3 more weeks. Thank you.
Your engine combo sounds really good, except I see maybe one problem, I dont know how many times a stock cast 460 crank will take a 6000 RPM shift. I thought that you had to run a forged crank for somthing like that. I could be all wrong but I figured that a stock crank couldnt take that. Could I be wrong?? Anyone??
Well, with the truck being driven mostly on the street, it probably won't be seeing 6000 too many times. If I decide to run it at the strip, it might see 6000 a few times. This is going to be a street engine for the most part. I just want something that will be fun to drive.
Just a little update. I'm going to take the truck in and run it on a chassis dyno to get a baseline for HP and Torque. Then after I get the new engine together, I'll run it again. Going to be interesting to see the difference.