Gert’s Engine Rebuild & Upgrade (Chasing 300Hp, yes another one sorry)

[Gertvr]

Recently while fixing some perpetually increasing oil leaks (’78 RoW SC engine) I discovered a broken valve spring and while digging deeper a broken oil control ring.

Since I was going to rebuild/ upgrade the engine in a few years time to start club and historics racing I decided to accelerate the program and perform the rebuild & upgrade in stages. The car would eventually be campaigned as ’74 RSR 3.0L (IROC with the correct tail ).

Stage 1: Chase 300hp with somewhat streetable engine as it will still be dual purpose, DEs, Racing schools, Mountain excursions and some limited Street use (Now)

Stage 2: All out dedicated race car max Hp with reliability to last at least 2 seasons (2 years down the line or as budget allows)

Stage 1 Build sheet (Overall budget $14K):

Short block, P&C
Mod Case for oil pump and line hone main bearing carriers
GT3 oil pump
Puater rods
JWE coated big end bearings
GT3 main bearings
Cross drill crank for 2&5 oiling
Magnaflux crank & polish journals
Bore and re-plate, hone Cyl (Mahle Nicasils)
10.5:1 Wossner pistons
Balance crank assembly

Heads, Cams, Chain boxes:
DC62 cams on 106 lobe centers
Re-bush rockers and new shafts
Upgraded valve springs (8Krpm safety margin)
+1mm Valves (SI swirl polished for this build)
Refurbish & Twin-plug head with new Ex guides
Home port heads and inlet manifolds (yes yes I know, but want to do this myself, will start a new thread for this)
Upgrade to later style chain tensioners and replace shafts
Replace all sprockets, ramps and timing chains

Ignition, Carbs and Exhaust:
Twin-plug distributor (Henry)
Twin MSD 6AL and related coils
42mm Venturi for 46 PMO carbs F16 emulsions etc
13/4” equal length primary header with Burns SS 3-1 merge collectors with reverse cone megaphones (Flowmaster series 10 delta flow or Burns slip on mufflers for street and sound restricted tracks)

I will update as things progress. Below is a picture of my car for reference

[lucittm]

You didn't ask for comments or opinions but, hey, this is a forum:

Potential budget busters-
Upgraded head studs?
Ti valve retainers?
I hope your shop is going to magnaflux the crank before they cross-drill and polish it.
With the eventual plan to compete with this engine, I would use stainless fasteners and safety wire all critical components.

Mark

[Gertvr]

Hi Mark,

Thanks for the feedback, yep, was assuming folks would chime in where necessary since its a forum. The head studs were upgraded by the PO and looks like they are all steel studs, is this still a point of concern that needs to be addressed?

Very good point on the fasteners, which ones should plan on upgrading to SS and safety wire.

[cgarr]

Are you using the original SC heads then? If so, Maybe to save some time and trouble, They say the stock Carrera heads flow good past 300 hp. "1topcat" looks like a similar build here except for some internals, He is using Carrera heads with DR racing springs which we just rebuilt for him.

1982 3.0L rebuild

[lucittm]

Since you are doing such a fine job inside the engine, I would use the studs that Supertec sells or maybe even ARP. Although it would be good to know what the PO used, maybe they are aftermarket and stronger than OEM.

For safety wiring critical fasteners, that usually means anything that secures fuel, oil, or the braking system. Also, obvious safety devices such as rollbar, seatbelt, etc.

Plus, it looks cool...

Mark

[Gertvr]

Originally Posted by lucittm

You didn't ask for comments or opinions but, hey, this is a forum:

Potential budget busters-
Upgraded head studs?
Ti valve retainers?
I hope your shop is going to magnaflux the crank before they cross-drill and polish it.
With the eventual plan to compete with this engine, I would use stainless fasteners and safety wire all critical components.

Mark

Mark, I am not sure about the benefit of the TI retainers on this relatively mild configuration, I would rather not spend the money there unless my view is ignorant and someone can correct me. Planned it as part of the 2nd Phase build.

[BReyes]

That is so Jose Gaspar! Lol, you know it is Gasparilla in Tampa this weekend.

Been a while since been to your parts. Jack Lewis did a PPI for me several years ago. Looks like a fine example you have there.

That is some serious plan. Should be a very strong competitor.

Regards,

[Gertvr]

Funny you should mention Jack, he is very knowledgable , I am getting a lot of good help form him on the engine

[Kroggers]

Sounds like an interesting build, looking forward to the details...

[carslutt]

wow!... i will have to watch this come together. i just picked up a 78' SC my self and plan to do a motor build a lot like this but with mega squirt injection added into the mix.

[Gertvr]

Its a been a while since I started this thread and its time for an update:

After some investigation i came apon a ratio for throttle to venturi sizing and the 46 PMOs were slightly over the edge with 42mm venturis. That lead to the decision to be "future proof" by upgrading to 50mm PMOs with 41.5 mm venturis for the current configuration. This leaves room for expansion in the future when the engine will be in full race trim and should still be somewhat driveable.

With the funds i had available I ordered the following already:

Wossner pistons
Pauter Rods
Bored and replated cylinders
GT3 oil pump
Burns SS merge collector
Valves
rocker shafts

The cams are still work in progress and i expect them to be complete some time this month. One head was updated with the new +1 mm valves as a base for the headwork that i am doing in another thread.

The collectors on my current headers are not the most efficient and opted to go with these Burns SS merge collectors as the header primaries (1.75") are also a little on the big side. I didnt want to go one size down on the primaries as there are a few things i want to try to minimize reversion on overlap at the port header intersect. This merge collector will be used for trail fitting and will go back to them to complete the exhaust. The craftsmanship on these collectors are outstanding.

The list of things to order is still very long but I am out of moolah for now and will focus on headwork until mid April.

Here are some pictures















Current Header



Cheers

Gert

[Gertvr]

Hi,

Finally.... out of hibernation, it felt like I would never get to this point...

A lot has happened since my last update. I will probably be able to complete the build by the end of the winter ready for the Spring season and will document the build for future DIY reference.

If anyone has any objections to me posting researched data please let me know. All sources for the data will be kept confidential if not publicly available and will reflect my final build criteria and critical tolerances. Comments and critique are always welcome.

The budget for the build has gone through the roof (not that I’m totally surprised but it’s still painful) due to initially unplanned upgrades and component changes which delayed the build till now.

To name but a few:

1) Straight cut steel IS shaft gears (gear reliability for use with high tension valve springs and high capacity GT3 oil pump)
2) Change from Glyco to Genuine Porsche on IS, main and big-end bearings (insurance )
3) Manually adjusted chain tensioners (insurance)
4) Adjustable Cam Sprockets (ease of cam timing , had to replace the sprockets anyway)
5) New head studs (insurance)
6) Extensive work on exhaust ports with race valve job by Bill D @ Xtreme cylinder heads (get exhaust ports to flow better)
7) Sleeving of the main bearing webs (insurance)
8) Genuine Porsche parts (timing chains, IS sprockets, ramps and cam feed oil lines) (insurance)
9) Change direction on headers with stepped primaries and merge collectors. (better torque)

In the mean time the following items were completed :

1) Refurbishing of the chain tensioner idler arm bushes and new shafts in chain boxes (CGarr)
2) Engine Case work i.e. cleaning, Oil pump mod, boat tailing, sleeving of the main bearing webs, JB Racing oil squirters (JB Racing, Self)
3) Crank oiling mod for #2 & #5 rods & new distributor drive gear (JB Racing)
4) Magaflux, polish and balance crankshaft and other engine components (KSS Sunbelt)
5) DR62 Cams and Refurbished rocker arms (Camgrinder)
6) Measuring and tabling of all journals diameters and clearances (Self, KSS Sunbelt)
7) Convert cam tower spraybar end plugs to screw in plugs (KSS Sunbelt
8) Machining lower valve covers for 2 plug heads. (CGarr)
9) Set ring gaps (KSS Sunbelt)

One of my main focus areas so far was to ensure that I get as much as possible data on suggested critical clearances for a race type engine, ensuring that they are as indicated and that all other measurements are within spec.

My measuring tools are not the best and I had to get 2nd opinions on all critical measurements. Luckily the Kinetic Motorsports group's Sunbelt Engine shop is within driving distance and they did all the measurements, sonic cleaning and miscellaneous machining.

Some setbacks:

The finished cylinder bores were too big 0.004" after the boring and plating and had to be redone, one piston wrist-pin to bore clearance is out of spec and one rod small end to wrist-pin clearance is out of spec and has to be double checked and rectified. I will post the measurements in the next update

Updates to follow:

Cheers

[Gertvr]

I had a few setbacks with getting all components together to complete the build. The Wossner pistons I had, had a myriad of problems and a friend lost a motor as a result and I had to change direction.

I worked with Mike at JB Racing and he specified JE pistons with CR@11.5 to work with the camshaft (314/296-106 Elgin). All other components are now in house and the build will start this weekend

I Completed all measurements and all are in spec. Here are some pictures before assembly.

[Jeff Alton]

looking good! However if you are running 11.5:1 CR the heads in your picture are all missing a spark plug hole....

Cheers

[tom1394racing]

I agree with Jeff that 11.5 CR will need a twin plug set up unless you run race gas only.

Here what you might expect with your build:

Another RSR Clone Project - Dyno Day

[AlfonsoR]

^^^^ Guys, I think he mentioned that twin plugs are in the plans.

I never get tired of these posts. Hope to learn some good stuff here.

Good luck!!

[Gertvr]

Originally Posted by Jeff Alton

looking good! However if you are running 11.5:1 CR the heads in your picture are all missing a spark plug hole....

Cheers

Originally Posted by tom1394racing

I agree with Jeff that 11.5 CR will need a twin plug set up unless you run race gas only.

Here what you might expect with your build:

Another RSR Clone Project - Dyno Day

Taking your advice, added another plug hole :-)



Headwork was done here Homebrew Head Porting: Attempting the dark art .....

[Gertvr]

Started assembly yesterday in an exteremely hot in Atlanta, low 90's with very high humidity. Used Henry's case sealing kit with "Wrightwood Racing" gasket set with the viton seals. Everything went well up to the time that I had to get ready to mate the cases. I spread the 1194 for perimeter sealing with a small wide brush and kept the layer thin as was suggested on the tube and covered all areas well and 574 on the webs, again a thin layer and the 1211 on the #8 bearing mating surface. By the time i mated the cases which could not have been 10 minutes after i started spreading the 1194, the 1194 was already kind of dry i.e. not very taky.

There was squeeze out after i mated and bolted the case down but not as much as i have seen from others. I worked as fast as i could and bolted the through bolts down 1st it took about 15 minutes and the perimiter another 10 minutes there after.

As this is my 1st Porsche engine i am now doubting myself about the perimeter sealing because of the small amout of squeez out. Attached some pictures of the process showing the case with the sealant before i mated the cases. The big question for me is do i have enough sealing or not, and, do I stop and do it over or continue and trust that all will be ok. Hopefully some experts can chime in.














Cheers

Gert

[Walt Fricke]

From what I can see, you have plenty of "squeeze out." Your before picture seems to show complete coverage. Unless your fingers unintentionally wiped some part clean when putting the halves together, you should be good based on that alone. Even very small squeeze-out ought to verify that you have a full seal behind it.

I'm only familiar with the orange Loctite, but this stuff ought to behave the same way in that regard. I'm a bit slapdash, but have never had a case leak at a seam.

[Gertvr]

Thanks Walt, I also looked at the squeeze out on the inside of the case and it was roughly the same. I am going to move ahead with the assembly.

Cheers
Gert