Blue Thunder CJ heads/Stroker combination questions

Hello-

I'm new to big block Fords, but not new to Fords or racing. I picked up the top half of an engine from a local racer (impulse buy), and I'm still figuring out what I should do with it. I was impressed by the engine it came off of, because it was a relatively low budget combo. Ported blue thunder heads (BBC exhaust), victor 460 intake, cast crank, cheap aluminum rods, stock block, 532cid. From what I understand the cam was around .700 lift and was limited by piston to valve clearance. Compression was around 13 or 13.5:1. This engine made 870HP on the dyno, which I thought was great. It went 148mph @ 3200#, so I don't think it was a happy dyno either.

Regardless, I'm trying to decide if I should put together a similar combination and have fun, or if I should build a bigger engine, or if I should tame it down and build a bigger engine with less compression and run it on pump gas.

My questions are:

1. How big a motor can this top half support (I got heads, intake, rockers, pushrods, etc from the engine above) ?
2. How big a motor can a stock block support?
3. How much power can be made on pump gas (if I go that route), and how big should the engine be if I do that?

Thanks very much for any help you can provide.

#1and 2. Sounds like you are wanting to do a stock block deal. 557ci is normal for top ci in a stock block. These heads would do fine.
#3. Stock block, big stroker, and pump gas, possible to do, but you will need some big dish pistons. If you want to do this, a smaller ci engine would be more friendly. Maybe a 514ci with a 4.15" crank, or a 521ci with a 4.3" crank.

Be aware, that these heads are going to make a lot of hp, and you will be at the limits of the stock block capabilities. An A460 block should be strongly considered at this power level. There are a couple of ways to make the stock blocks better, but that money to upgrade would be better served towards the purchase of an A460 block.

wrong post

schmitty wrote:#1and 2. Sounds like you are wanting to do a stock block deal. 557ci is normal for top ci in a stock block. These heads would do fine.
#3. Stock block, big stroker, and pump gas, possible to do, but you will need some big dish pistons. If you want to do this, a smaller ci engine would be more friendly. Maybe a 514ci with a 4.15" crank, or a 521ci with a 4.3" crank.

Be aware, that these heads are going to make a lot of hp, and you will be at the limits of the stock block capabilities. An A460 block should be strongly considered at this power level. There are a couple of ways to make the stock blocks better, but that money to upgrade would be better served towards the purchase of an A460 block.

Thanks for the info!

If I was to do a pump gas 521 with this top end, how much power can be made with a fairly streetable engine? It would be a stock block with a forged crank and rods, and good pistons.

You can make way more power than you could ever hope to control on the street. With a 521 combo, on pump gas, over 600hp/600tq is possible. I don't know what you are putting this in, or your abilities as a driver, but that is too much for a street engine. With the kind of torque you will be generating, it will be hard to control tire spin and will be a real bear to drive. If this is going to be a strictly street deal, just do a 460-472ci deal with a factory crank. IMHO put a relatively small camshaft in it, to keep the peak tq/hp in a drivable rpm range. I don't do cams, but there are several here that do in our vendor list. Be very honest with them in that you want a "street", not an all out optimum cam.

schmitty wrote:You can make way more power than you could ever hope to control on the street. With a 521 combo, on pump gas, over 600hp/600tq is possible. I don't know what you are putting this in, or your abilities as a driver, but that is too much for a street engine. With the kind of torque you will be generating, it will be hard to control tire spin and will be a real bear to drive. If this is going to be a strictly street deal, just do a 460-472ci deal with a factory crank. IMHO put a relatively small camshaft in it, to keep the peak tq/hp in a drivable rpm range. I don't do cams, but there are several here that do in our vendor list. Be very honest with them in that you want a "street", not an all out optimum cam.

I do appreciate the reply, but I need more than that. It will be street driven, but not street raced. When I do take it to the track, I'm looking for single digits on pump fuel and on motor. I already have a small block car that almost does that (real close). This will be going in a 1965 Comet that won't be heavy, but won't be light either. I also have a small tire turbo car with 1300+hp, so I know how to get down the track, and I'm serious about doing it.

So I guess I'm honestly asking what the most I can do on pump gas with a streetable stock block combo is.

Thanks again for all your help. I've never owned a big block before.