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Need some engine advice . . . are you listening Gordon?

FM Former Member
Almost finished up shortening and welding up the chassis for the Fiat; shortened/welded the pans, but I'm waiting to put them in until I raise the e-brake and shifter boxes and run the tubes.

With the weather as it is, it seems like a pretty good time to begin getting the engine underway and I could use some advice (not just opinions) on the parts going into it. I already have a little stroker with 92mm barrels all set for the 356, the engine for the Fiat will mainly be built out of the used left overs.

What I got so far is:

78 eight-dowel stroker crank
Eight-dowel lightened flywheel
KEP pressure plate and clutch
Dual relief case opened up for 94s and full flowed
Windage tray
Deep sump
94mm A pistons, buttons, and pins
Stock rods
40/35 heads, amateur porting, cleaned and smoothed but nothing special
Stock ratio rockers on solid shafts
HD single valve springs
Titanium retainers
VZ25 cam
Scat lifters
Straight-cut steel on steel gears
Single DCOE carb
Scat manifold


I was wondering if this combination of parts would yield a streetable engine?
Can I use the A pistons with the stock rods and 78 crank or will I need to switch to Bs?
If I switch to B pistons, what length rods and what size shims should I go for?
Am I getting close to trouble with the VZ25 and single HD springs? I know that the ramps are a touch radical, but . . .
Will the stock rockers hold up considering the better, wider retainers and single springs?
Should I switch over to chromoly push rods or will they stress the rockers further?

Is there any thing else that I need to be aware of, include, etc. I'm trying to get away with parts on hand, so I kinda don't want to add much to the mix, but I can subtract easily if needed. Of course, I could add just a bit if it will make a difference. Like I "said," it wont be the perfect combination nor best performing engine, but I'd like to know if the combination will at least work.

Thanks ! I thought that I would try here first before exposing my tender neck to those tiny fools on The Samba.

TC



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FM Former Member
Almost finished up shortening and welding up the chassis for the Fiat; shortened/welded the pans, but I'm waiting to put them in until I raise the e-brake and shifter boxes and run the tubes.

With the weather as it is, it seems like a pretty good time to begin getting the engine underway and I could use some advice (not just opinions) on the parts going into it. I already have a little stroker with 92mm barrels all set for the 356, the engine for the Fiat will mainly be built out of the used left overs.

What I got so far is:

78 eight-dowel stroker crank
Eight-dowel lightened flywheel
KEP pressure plate and clutch
Dual relief case opened up for 94s and full flowed
Windage tray
Deep sump
94mm A pistons, buttons, and pins
Stock rods
40/35 heads, amateur porting, cleaned and smoothed but nothing special
Stock ratio rockers on solid shafts
HD single valve springs
Titanium retainers
VZ25 cam
Scat lifters
Straight-cut steel on steel gears
Single DCOE carb
Scat manifold


I was wondering if this combination of parts would yield a streetable engine?
Can I use the A pistons with the stock rods and 78 crank or will I need to switch to Bs?
If I switch to B pistons, what length rods and what size shims should I go for?
Am I getting close to trouble with the VZ25 and single HD springs? I know that the ramps are a touch radical, but . . .
Will the stock rockers hold up considering the better, wider retainers and single springs?
Should I switch over to chromoly push rods or will they stress the rockers further?

Is there any thing else that I need to be aware of, include, etc. I'm trying to get away with parts on hand, so I kinda don't want to add much to the mix, but I can subtract easily if needed. Of course, I could add just a bit if it will make a difference. Like I "said," it wont be the perfect combination nor best performing engine, but I'd like to know if the combination will at least work.

Thanks ! I thought that I would try here first before exposing my tender neck to those tiny fools on The Samba.

TC



FM Former Member
I know, it's an odd list, but it's what I have on hand and would like to use rather than buy new stuff . . . you know?

Most of it will probably work without resulting in a four cylinder grenade, I just want to be sure that I can make the package perform as it is or do I need to change/delete something?

Like the cam, maybe. It's a wonderful cam, but it has severe ramps and can pound the case after a time. It has that buzz-saw rev capability like the ricers have and with the lightened flywheel it's beyond insane, but what about the single hi-rev springs, with they last? Dual springs would further pound the case and stress the stock rockers, but you can't use ratio rockers with a VZ. I don't really want to buy an FK and a small W Series isn't worth shit, so do I really need to spend new $$ for a WEB, or can I adjust the mix of what I have, maybe just find some stronger SCAT rockers or . . .

Like I said, an odd mix, but it's a build-up of the leftovers, just want to know if they'll all work together.

Gordon? Where the hell ARE you ? ! ? ! ? !
Gordon NicholsGordon NicholsMassachusetts 1993 CMC Supporting Member
I was working on my new build. I find I get lots more done when I'm NOT on here!

Th "A" pistons should be OK, but you didn't mention what you're using for jugs, so I'm jus' guessin, here. Heads are fine, considering.

That AZ25 cam scares me. It's built for dirt tracking and likes revs way North of 4 grand, will certainly wind up fast but probably won't idle for beans below 2 grand. Or if you can get it down under 1,500 at idle it'll lope like hell. You might consider an Engle 120 instead. Smoother, less radical, slower ramp-up but it'll idle "normally" (800-1,000) with normal asperation. (might run cooler, too)

Speaking of carbs (nice segway, that) I'm not familiar with that carb (never used them), but Scat's single carb manifold used to also fit a small Holley which was da bomb. I ran them on dune buggies years back - bolt 'em on, adjust the jets and never look back - for years! Merklin had something similar on one of his builds and liked it, too - WAY better than screwing with duals, PLUS you can run vacuum advance!!!!

On the high end, single valve springs are ok (HD, of course) and should get you a 6,500 rev limit. Dual HD springs will get you to 7,500 or better, but why? Is this for the street or strip? Dual HD springs will wear everything out in a few, short seasons fo another grand of rpm and no appreciable increase in torque.
FM Former Member
Thanks Gordon.

A buddy has a couple of used W-Series cams, but no lifters matched to them. I may tap him for one and try my new lifters with it or maybe work a trade on The Samba with the VZ25 and go for a 120 as you suggested.

The DCOE is a big side draft carb, the one that you always see hanging off of draw-through turbos on drag cars. I have an antique intake for it that orients the carb so that it points straight rearwards. From behind the car, it looks like a 2in bore double barrel shotgun is pointing at you. We ran the two of them on a cross-ram manifold on one of the TR8s, I figure that the 8 had a 4.1 liter in it and the VW engine will be kinda close to 2 liters, so it just might work. Otherwise, I have an old EMPI manifold and a Zenith that I'd like to use up. Without resorting to duals, I could also try a BugSpray/Holley or a 2.75 in SU on one of my home made manifolds.

Choices for sure, but no knowledge to make any sort of educated decision, you know?

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