[KEN CROCIE]

The solution is screaming at me! That HEI has a way to slow advance curve for the cam, engine size, and CR . Get full mechanical advance in by 2500 engine rpm. Limit that advance to 20 deg. crank. limit the vac. adv. to 12-14 deg. Try initial timing @ 16deg.(listen for ping).The RA4 cam itself is not to big , but the equipment surrounding it considerably reduces it's performance potential. The log manifolds just kill the performance of a big overlap cam. they allow adjacent cylinder exhaust dilution due to crosstalk in the manifold. in other words you can have one cyl. in the overlap phase sucking in pressurized exhaust from the other cyls. I have dyno tested RA4 manifolds vs. headers and lost 28 HP with the RA4 manifolds with the same size cam on a 400. In addition the headers allowed the engine to idle better and smoother.

[KEN CROCIE]

The Rhoads lifters are a good idea - IF - the were being broken in on a new cam and not on a used cam.

[ScumOne]

Originally Posted by 72LuxuryLeMansLa.

I'm no expert but given your stated driving situations B-Man is DEAD ON with the factory 068 cam suggestion. You want it to spin the tires but idle well (AC) at lights and drive it a bunch so that's that in my mind. Now, when they list pistons as being 9.5:1 Compression, that is useless information. The piston is one of five or six things that determine the Static Compression Ratio..........https://en.wikipedia.org/wiki/Compression_ratio#Formula

Maybe this will help.

The seller scanned & sent me the original speed shop 1st page.

Pistons: .030 over (guesstimate) Keith Black Hypereutectic Pistons, Dish, 4.150 in. Bore, 5/64 in., 5/64 in., 3/16 in. Ring (seems Summit sells these, and they only come in sets of 8). UEM-KB346-STD
Dome volume +17.00 CC

Block was surfaced, not positive that means it's a "zero" deck clearance, but let's say it is for giggles. 0.0 clearance.

Felpro gaskets, head gasket compressed is .039 thick.

62 heads have 72cc chambers, which may also have been shaved, but let's say they haven't.

Put that all in the compression calculator on the Summit Racing site and it comes back with the following:

Compression Ratio : 9.51 : 1
Total Displacement (in.3) : 202.9
Total Displacement cc's : 3326.23

[FrankieT/A]

I have run the SPC-8 in numerous 400's, granted with higher compression, and never had a problem with idling, the car dieing at stops or running hot. No Rhoads lifters, just Johnson's. No issues. I have also run it in a complete 12 headed Ram Air III with A/C and 4.10 gears and no compressor issues. You do have loosen the converter up a bit, not much.

Also 1.65 rockers will clear the pushrod hole in the head if you use 5/16 pushrods. Everybody always forgets Ram Air IV's come with 11/32 pushrods and THEY need the holes opened up.

[rtanner]

From experience, DITCH the ra4 cam right now, your driveability will improve so much, you will think its whole nother car!!!! BTW ive had your deal happen twice on cars ive bought, tried the dicking around with working on everything trying to keep from changing cam, total waste of time, car was great as soon as cam change, 2nd car changed it right off bat, was very happy, BTW my current 69fb has a ra 4 cam and i love it, But its 469ci 10.5 comp, 4.10 gears and 4 speed, my factory 400 cars all got 068 melling cams and i love em!!!!

[Steve C.]

It's very interesting how people tolerate different cams and the amount of duration involved. Over 20 years ago my origional stock RAIII 400 in my TA was changed to a old fashion Comp 280H cam with 230 degrees duration and it was no issue in my opinion. With the engine in stock form other than a change to headers and the cam it ran mid 12.80's at the time at about a 3800 lb race weight. Nothing to write home about today but ok back then. That said, it came from the factory with a TH400 and 3.73 gears and no A/C. What made it work out ok was a change in the torque converter, the appropriate stall up near 3000-plus give or take, yet coupled out on the street. It was a old B&M holeshot converter, similar to a tight 10-inch today from Continental.


.

[East]

I remember purchasing a Crane Blazer cam back in the early 1980s under recommendation of Fred Garcia who worked at National Performance on Fremont Street in Las Vegas. I bought a lot of parts from him for my 1969 Firebird in search of more performance. He also had a 1969 Firebird and was heavily into Pontiacs, which was a good thing back in those days because Pontiacs were rare compared to all else. Whenever I would seek information for more performance, it was a Chevy or Ford guy offering up what worked for their brand.

The specs were .450 int .465 exh 288° dur int and 302° duration exhaust. The cam was installed in a 400 using either an Edelbrock P4B with a speadbore Holley 6210 or Holley Street Dominator with same carb later switched to Holley 750 vac sec 3310-3. The cylinder heads were 1968 #16 heads that I bought from Fred for $50. Three tube headers were used for the dual exhaust system. Transmission was a TH400 and the gears were most likely stock because I had yet to get into modifying the rear. I was also using the popular torque converter swap of a TH350 if that makes any sense. I believe it would be something like a 2200 stall speed.

The engine pulled hard and Big Fred was impressed. He actually asked me what cam I was using because I was always swapping parts and was surprised how well the Crane Blazer cam performed.

I could tell the differences between the two intake manifolds in performance when I was getting on the freeway ramp and building speed to 65 mph. The single plane pulled hard above 3000 RPM and on where the P4B pulled hard early but dropped off much earlier than the Street Dominator single plane.

I would be satisfied with either but the Holley Street Dominator seemed to be the better of the two all around.

I haven't been able to find the exact cam and wondered what current cam would be a current version.

[Steve C.]

I should also note my previous comments with the Comp 280H 230 degree cam is certianly not apples-to-apples here. it has a lot less seat duration than the origional 041 cam.

Side topic, but not related- the Holley Street Dominator intake often doesn't get the credit due. It is a very good intake and works well in many applications on the street. And fits well under stock hoods !


.

[dmac]

Since changing lifters is soooo easy compared to a cam swap. try that. I've had rhoads in two 400 motors, one with a RAIV cam. They 'tame' a cam a bit at low rpms and the slight 'ticking' never bothered me. Of course, those cars were load enough to mostly cover up the sound of the ticking. Your cams duration is reduced with rhoads.

As far as exhaust, stock manifolds really won't cut it at higher rpms. They don't move enough air quickly enough. Maybe just lifters and headers or Ram Air manifolds will do the job. You don't need 1.65 rockers if the motor is already overcammed. And Rhoads now has what they call adjustable lifters. As a plus, you don't see any complaints about rhoads lifters wiping cam lobes.

Timing and vacuum advance setup can also really affect power if your carb is good.

One of my motors went from about 8-9 inches of vacuum to about 17 with rhoads at idle. I don't recall if that was the motor with the RAIV cam. Plus I had right at 10:1 CR

[FrankieT/A]

Not intending to hijack this thread and no disrespect to the OP.....
I've always used the RA IV cam and as Steve said its amazing what people will put up with. I really have no drivability issues. But I'm seriously considering the Lunati VooDoo 705. I like the high lift aspect of it and moderate duration.

[ScumOne]

Thanks for all of the replies. The Bird is in the shop getting it's minor electrical issues checked out, then it gets a new turn signal switch, and a check of the A/C system.

After that I'm going to have the distributor advance checked (swapped HEI dizzy in there now), and the carb as well to see if it's set too rich.

I know the torque converter and TH400 have been rebuilt, not sure what the TC specs are, they're not on any of the mountains of paperwork. The TH400 did get a shift kit installed, and it's working well, so I have to think the timing, dizzy advance, old spark plugs/wires, and a carb adjustment should take care of it.

If not then I'll consider getting the Rhoads lifters next before swapping out the cam.

[rtanner]

Originally Posted by ScumOne

Maybe this will help.

The seller scanned & sent me the original speed shop 1st page.

Pistons: .030 over (guesstimate) Keith Black Hypereutectic Pistons, Dish, 4.150 in. Bore, 5/64 in., 5/64 in., 3/16 in. Ring (seems Summit sells these, and they only come in sets of 8). UEM-KB346-STD
Dome volume +17.00 CC

Block was surfaced, not positive that means it's a "zero" deck clearance, but let's say it is for giggles. 0.0 clearance.

Felpro gaskets, head gasket compressed is .039 thick.

62 heads have 72cc chambers, which may also have been shaved, but let's say they haven't.

Put that all in the compression calculator on the Summit Racing site and it comes back with the following:

Compression Ratio : 9.51 : 1
Total Displacement (in.3) : 202.9
Total Displacement cc's : 3326.23

very good build, same as stock except for reduced compression, get that ra4 cam, which is a terrible match for a STOCK 69 fb auto, air, p/s, DRIVER, regardless of these other comments about other cars, engines, and combos, you will be very happy with your car when you do.

[AG]

Originally Posted by ScumOne

Maybe this will help.

The seller scanned & sent me the original speed shop 1st page.

Pistons: .030 over (guesstimate) Keith Black Hypereutectic Pistons, Dish, 4.150 in. Bore, 5/64 in., 5/64 in., 3/16 in. Ring (seems Summit sells these, and they only come in sets of 8). UEM-KB346-STD
Dome volume +17.00 CC

Block was surfaced, not positive that means it's a "zero" deck clearance, but let's say it is for giggles. 0.0 clearance.

Felpro gaskets, head gasket compressed is .039 thick.

62 heads have 72cc chambers, which may also have been shaved, but let's say they haven't.

Put that all in the compression calculator on the Summit Racing site and it comes back with the following:

Compression Ratio : 9.51 : 1
Total Displacement (in.3) : 202.9
Total Displacement cc's : 3326.23

The block doesn't look like it was decked before assembly. Is the deck height reported on the paper work?

[Blued and Painted]

Originally Posted by ScumOne

The Bird is in the shop getting it's minor electrical issues checked out,

Some young tech's run into problems if they are unable to connect there laptop to the car.

[ScumOne]

Originally Posted by AG

The block doesn't look like it was decked before assembly. Is the deck height reported on the paper work?

The machine work portion states the following work was performed:
Machine Work, Line Hone, Bore, Hone, Vat, Turn Crank, Balance Rotating Assy, Resize Rods, Press Pistons on Rods, Valve Job, Install Hardened Seats, Guides, Surface

I'm guessing surface means they had to shave a few 1000th off of either the block or heads, it's not exact on which.

Originally Posted by Blued and Painted

Some young tech's run into problems if they are unable to connect there laptop to the car.

I've got old school techs working on it. Pretty sure the only computerized options in this car is the HEI dizzy and the upgraded AM radio that's now also FM with MP3 hookup.

I did a youtube search and found a 69 TA vid with the motor running. Mine doesn't lope like this. So I'm guessing it's not an RA IV cam that's in there, and probably the 068 or 067 grind.

https://www.youtube.com/watch?v=tds9QtGYsik

[rad400]

maybe 744 cam.

[Will]

Those are some pretty healthy dishes in those pistons. If they didn't mill the heads (anything in the receipts about that?) then I'd guess your actual compression ratio is no higher than 9.5:1 and possibly less. Not really a big deal though, anywhere from 9-9.5:1 will work fine.

I'll pile on with b-man's suggestion of the 068 cam being a better choice than the RAIV. Your combo is just not suited to take advantage of the RAIV's characteristics. For it to work best in a 400 you need better flowing heads and a free flowing exhaust at a minimum.

Another good choice would be the Summit 2801. That might actually be a slightly better choice than the 068 with a lower compression ratio and it has more lift than the 068.