Help with my 400
 

I pulled the 4002bbl on my 68 wagon. It’s got 60k. I pulled it because it had some leaks and a broken engine mount. The lower end checks out good. Just looking for some tweaks for the top end while keeping the 2bbl setup

This is what I need to fix or shop for.

Harmonic Balancer-
It’s not bad, But it has a good size groove where the seal sat. Buy new or use one of those sleeves?
Timing chain-
it’s plastic and missing some teeth. Is there a need for a double roller?
Cam-
Is there a better 2bbl stick to put in than stock?
Heads-
The push in studs are pulling out, the previous owner doubled up the nuts to get the correct valve lash. Do I rebuild or look for a better used head?
Timing cover-
It’s really rotted out... do I Put a 1970 11 bolt on it or buy another 8 bolt ( it’s has a/c) also do the pulleys match up to a 70’s setup?
Gasket set? Who makes a good compete set
Thanks for your recommendations
John-

Balancer: if it isn't wobbling you can get by with a sleeve.

Timing chain: just get a good metal timing set, no need for double roller.

Cam: yes. The arguments are long and varied...

Heads: this really needs to be fixed. Convert to screw in studs or a later set of heads to handle manageable compression ratios that already has screw in studs (6X).

Timing cover: I would replace it with an 11 bolt cover, I don't believe the balancer will have issues clearing it like a '67 or earlier would. I'm fairly certain the alternator mounting bracket works with both the 8 & 11 bolt cover, but someone may know for certain. Keep all of your pulleys as one set together regardless of what you choose (don't mix and match a '70 set with a '68 set).

What heads are on it now? You may already have low compression heads, since your engine is a 2 BBL.

The stock replacement cam for all low compression V-8's is the Sealed Power CS641. It is a duplicate of the 066 cam, which is a great choice for a low compression 400. It doesn't need fancy springs or any other modifications. Many will suggest the 068 cam (smelling SPC-7) it too was the is with stock springs.

Do you plan to remove the heads?

You can helicoil the rocker stud holes and install 7/16 studs. The special helicoil tap will work in the old rocker stud holes, no need for any drilling. This could be performed with the heads on the engine, but would require a lot of masking off of the rest of the exposed head area to keep metal shavings from going where they don't need to be.

BOP engineering makes a one piece oil pan gasket, that many here have used it with success. They also make a neoprene rear main seal, but most recommend using a graphite type rear main seal with a stock crank. Butler performance has them.

Fel Pro makes great gaskets, just don't use the rear main seal or pan gasket in a kit, the reasoning for my mention of the afore mentioned rear main and pan gaskets...

Butler offers a new 8 bolt timing cover for $215.00. They also show reconditioned units for much more...I wonder why those are higher...

Timing chain info: https://www.enginelabs.com/engine-te...d-application/

Im actually am building 2 engines
The Blocks are YE and YC
Both have 60 k
I didn’t notice at first but Both have 15 heads on them
I was going to leave the heads on the 2bbl engine
But I will have a second set from the YE that I can fiddle with...

The ye is getting aluminum heads....eventually

My cart is loading up I’m going to go with the sealed power kit
I might try to re-stud the heads that are off the YE engine... to get the studs out I’m guessing heat and a slide hammer?
Where do I order the studs - helicoils from?

The missing teeth on the cam gear are either in your oil pan or possibly sucked into your oil pump. Lots of info on this site about that issue. FYI

No, no. A stack of washers and a fine thread nut will remove the press in studs. Have to use an impact though. Make sure to oil up the threads. Get more than one nut.
Helicoil is a brand name. Call part s stores, industrial supply places, possibly Fastenal.

If you are ordering Pistons, you should be able to get forged Pistons in their kit. Costs more, but worth every penny.

The only engine Iknow of that came with 15 heads was the 1970 455. I did not know 400's came with 15's...anyone?

15 heads (sometimes referred to as 215) were the small valve high compression head used on most fullsize car 400's. They were used on both the 290 horse 2bbl engine and the 340 horse 4bbl engine. If the car had the no charge regular fuel option (therefore it doesn't show up on the PHS) it would have 14 heads which had much larger chambers.

The 066 type cam would be a good fit as the original 2bbl cam while very smooth is very demanding on octane due to very high cylinder pressure. Of course if you drive it gentle the original cam is best as it provides better bottom end power which works well with the 2bbl carb.

I'd try to find a good used 8 bolt timing cover and if not readily available go for a 69+ 11 bolt. As for using a 11 bolt timing chain cover you can keep your pulleys if you use the early 69 water pump (9796351) but if you use the later pump you will need the matching deeper water pump pulley. All other pulleys are not affected. I've heard mixed reviews about the repro 69-70 timing cover, apparently some issues about the centering of the oil seal. The 68 and 69 front alternator strap are different but they can be used interchangeably in a pinch but they won't line up with the rear strap aesthetically.

"...You can helicoil the rocker stud holes and install 7/16 studs. The special helicoil tap will work in the old rocker stud holes, no need for any drilling..."

Are you sure ? :confused:

If I remember correctly, everything I've read here has indicated that you can tap the stock holes for the 1/2" bottom thread ARP studs, but a larger hole is needed for heli-coils. ???

http://forums.maxperformanceinc.com/...7&postcount=13

I've never done it. So, I'm just going by what I've read.

Several have posted that if you go with the 1/2" bottom thread ARP studs, you must remove some of the bottom threaded portion, because that portion is too long, therefore will bottom out in the hole. Don't know if a thick hardened washer, under the stud, would work, instead of removing stud material, or not. ???

" 15 heads (sometimes referred to as 215)..."

The 455 Ventura bracket car I bought had "215" heads on it. And, the numbers cast with the heads was 215, NOT 15. So, they may have been VERY similar. But, there were some heads that had a 15 casting number, & some that had a 215 casting number. Maybe one was used earlier in the model year than the other. ???

http://www.wallaceracing.com/enginesearch4.htm

Why change the studs. Unless you are using a more radical cam with high lift or heavy duty springs for a more radical cam, what's the point. I never saw press in a problem for stock or close to stock cams.

he mentioned that some had lifted

Drilling & tapping for screw-in rocker studs should be left to an accomplished machinist. Mention that as have examined several cracked rocker stud bosses on previous press in stud Pontiac heads, heads that were MUCH more Desirable/valuable than later 60's Pontiac press in stud heads.

Swapping to an 11 bolt timing cover, will need the correct "stagger" wp pulley & a '69 front alt bracket as the lateral spacing is also different. Not exactly an easy to find pulley in the AC diameter. Know this, as I ship out a ton of nice original Pontiac brackets, pulleys every year & never post a for sale listing here on PY or on eBay. Desiring a nice used '68 timing cover, stock those as well, currently have two.

I haven’t checked to see if the studs are lifted. But the doubled up nuts don’t make me think they arnt.
The YE has the same heads and they look good so I may just swap them over to the 2bbl engine

Are the butler timing covers out of round? They have a kit

A390GT, Those 15 heads look like my '70 15's from a 455 motor. What are the casting dates? That will help to know.

Dennis

I missed the part about some studs pulling out.

BTW, '70 #15 small valve heads came only on the B-body 360 hp 455. Mine cc'd at 90 cc's after a minor cut to true them up. The advertised compression ratio for the YH 455 was 10.0 to 1 in 1970. The HO #64 (D-port) heads had
slightly smaller chambers at 86 cc's and rated at 10.25 to 1 compression.

The optional 330 hp XV code 400 4-bbl (advertised 10.0 to 1 compression) in 1970 for the non-GTO A-bodies had #16 small valve heads that measured 82 cc's. I am having a set of these #16 heads gone through for a new Pure Stock Drags motor, so will report back when they are finished and cc them to see where they are exactly...again, just cutting enough off to true them up, not going crazy with a compression bump. The B-body 400 4-bbl and high compression 2-bbl used the same heads (#16's) as far as I know.

Dennis

My 455 originally had #15 heads. I have owned this car since 1979, when "real" high octane leaded gas was still available. When they phased it out leaded and replaced it with 93 octane unleaded, I had a continual pinging problem. I struggled with that for a couple years. Back off the timing and it ran hot. Octane boosters were for the most part snake oil. For a street driven car, it was a major pain to be constantly chasing the right sweet spot to eliminate the ping and not kill performance. The only fix was head replacement to lower compression. I ran 1971 #96 and they were great until previous repaired cracks let loose. Now I run 6X and have about 9.25 to 1. . If you plan a compression increase, make sure you get a cam that will control the pre-ignition. If it's for the strip, then you probably will buy race gas.

Here is an application chart from Ron's Pontiac Page website...

Dennis